Browse Topic: Air pollution

Items (1,298)
Public transportation serves as a crucial component of urban mobility, contributing to the alleviation of urban congestion, reduction of travel expenses, and mitigation of air pollution. Nonetheless, the dynamic passenger demand and the complex traffic conditions render traditional bus timetables inadequate, leading to ineffective allocation of public transportation resources. Consequently, it is essential to create bus timetables that are responsive to actual traffic scenarios and fluctuating passenger demand. This study regards the bus timetable planning problem as a Markov decision-making process within a discrete time framework, proposing a deep reinforcement learning-based optimization model for bus timetables. In particular, the model is designed to account for both bus companies and passengers, incorporating a state space and reward calculation method that emphasizes passenger comfort. Then Deep Q-Network (DQN) methodology is employed to issue instructions on whether a bus departure at each time, and bus timetable is generated gradually over time. Experimental results indicate that the proposed approach significantly reduces bus travel costs and enhances the overall travel experience for passengers in comparison to traditional methods.
Xu, JieXia, DongYang, JianxiWang, Bing
Heavy-duty vehicles significantly contribute to greenhouse gas emissions and urban air pollution, especially during cold-starts and transients when engine and aftertreatment efficiencies drop. Waste heat recovery (WHR) via Organic Rankine Cycle (ORC) systems offers a practical solution to improve fuel efficiency and cut CO₂ in real-world heavy-duty operations. This study examines ORC-based WHR integration into conventional and hybrid powertrains of an Isuzu FTR850 truck, analyzing four configurations: Shell-and-Tube or Plate heat exchangers with simple or regenerative ORC layouts. For hybrids, it compares two engine sizes and energy management strategies: an optimized fuzzy logic approach versus constant-power operation to enhance exhaust heat recovery. A validated quasi-static simulation framework is used to predict fuel consumption and exhaust properties over representative duty cycles. 2D performance maps using exhaust temperature and mass flow as inputs are used to model the WHR under off-design conditions. Results show that the recovery of waste heat WHR depends on the hybridization level and strategy. Conventional powertrains benefit most from Shell-and-Tube exchangers, recovering ~2 kWh of electrical energy per 8-hour cycle and reducing fuel consumption by 0.5%. Hybrid setups recover up to 3.9 kWh from exhaust gases with a simple layout coupled with a Shell-and-Tube heat exchanger under constant-power control. Electricity is used to support onboard auxiliaries and battery charging, further lowering fuel demand (-44%) and emissions. Finally, a multi-objective optimization was performed to exploit the synergy between hybridization and WHR while maintaining acceptable payload and battery operating conditions.
Donateo, TeresaMorrone, Pietropaolo
Passenger comfort within vehicles and aerospace cabins relies on finely tuned management of temperature, air quality, and energy use. This paper proposes an integrated HVAC framework that combines zonal climate control, intelligent airflow distribution, and real-time sensor data to maintain thermal balance across different cabin zones. Leveraging predictive thermal load modelling and machine learning, the system anticipates environmental changes—such as sudden shifts in external temperature or passenger load—and proactively adjusts heating and cooling outputs. Simultaneously, air quality is enhanced through a multistage filtration system, active air purification technologies, and dynamic CO₂ concentration monitoring. Comfort assessment integrates PMV (Predicted Mean Vote) and PPD (Predicted Percentage Dissatisfied) indices to adapting environmental conditions. Simulations and early-stage prototypes improve energy savings and improve occupant comfort and air quality. The proposed HVAC approach is a promising avenue for enhancing passenger experience and operational efficiency in both ground and air mobility platforms.
Mudavath, Lehitha SaiPatil, AshishSaha, Sudipta
This study aims to summarize the influence of air pollution on clouds and precipitation over the ocean and land. This paper summarizes global aerosol observation networks, including GAW and AERONET, as well as aerosol observation networks from various countries. Six typical regions, including North America, North Africa, South Africa, India, China, and the Indian Ocean, demonstrate aerosols’ seasonal and compositional variation patterns. This study also summarizes the impact of aerosols on the microphysical characteristics of stratiform clouds and precipitation mechanisms. The effect of aerosols on clouds varies across regions over land and ocean, and the impact of aerosols on the cloud water path differs significantly. Air pollution significantly affects precipitation by altering the microphysical properties of clouds, and this study is of great importance for understanding and predicting weather changes.
Wang, Mingxin
Maintaining optimal in-cabin humidity levels is part of occupant comfort, air quality, and the effective operation of climate control systems, particularly for functions like windshield defogging. This paper introduces a novel sensor fusion methodology for predicting in-cabin humidity distribution without dedicated humidity sensor. The proposed approach leverages readily available vehicle data, integrating information from ambient temperature sensors, in-cabin temperature sensors, occupant detection systems, window status, and climate control settings. By intelligently fusing these diverse data streams, a predictive model is developed to infer the dynamic humidity conditions within the vehicle cabin. We discuss the complex interactions between these parameters, such as the moisture contribution from occupants, the influence of external air ingress through open windows, and the dehumidifying or humidifying effects of the Heating, Ventilation, and Air Conditioning system. The paper details the development and validation of the predictive algorithm, highlighting its capability to estimate humidity levels under various operational scenarios. Challenges in modeling the transient and non-linear relationships between inputs and humidity, as well as the evaluation of the model's accuracy against ground truth data, are presented. Alos, initial results demonstrate the feasibility and robustness of this sensor fusion approach, offering an integrated solution for intelligent services and cabin climate conditioning are summarized.
Ghannam, MahmoudSchroeter, RobertShaik, Faizan
This paper introduces a sensorless approach for data-driven modeling of in-cabin CO2 concentration to optimize air recirculation flap control without the need for a dedicated CO2 sensor. Elevated CO2 concentrations, resulting from passenger exhalation, can impair occupants’ cognitive function and comfort. Current state-of-the-art solutions rely either on time-based control strategies, which lack responsiveness to actual cabin conditions, or on direct CO2 measurements via sensors, which increase system complexity and costs. In contrast, the proposed approach aims to replicate the benefits of sensor-based control without requiring physical sensors. In this study, a model-based methodology is presented, utilizing empirical CO2 measurement data collected from real-world test drives at varying occupancies, fan stages, vehicle speeds, and flap positions. Data acquisition involves a multi-gas analyzer positioned within the passengers’ breathing zone under controlled operation of the vehicle’s climate control unit. Based on these measurements, time-dependent CO2 concentration profiles are represented using exponential functions. These regression curves capture CO2 accumulation, depletion, and balancing behaviors, considering factors such as cabin leakage, pressure differentials at varying speeds, and ventilation conditions. These influences are inherently included in the calibration curves due to their empirical basis. The derived regression curves are implemented into a control model to simulate CO2 concentration throughout the drive, including situations where outside pollution is high and prolonged air recirculation is necessary – such as when driving through tunnels or behind trucks. On the baseline of this simulation, the sensorless control strategy adjusts flap positions accordingly, thereby minimizing both excessive CO2 buildup and unnecessary energy losses due to overventilation. By omitting CO2 sensors and relying solely on existing in-vehicle databus signals, this approach offers a cost-effective solution for cabin air quality management. Future work will focus on real-world validation of the control model and integration of exterior air quality monitoring as a complementary input.
Stürmer, MichaelGeier, BertramHofstetter, MartinHirz, Mario
Why precision engineering is defining confidence in next-generation internal combustion engines. In 2026, the global transport industry, and particularly the automotive industry, finds itself under competing pressures. Regulators are tightening emissions standards, with new regulations such as the EU's Euro 7 being proposed to reduce air pollution in line with net-zero ambitions. Fleet operators are managing ever-aging vehicle populations in uncertain economic conditions, and policymakers are accelerating mandates for sustainable fuels, with countries like the UK moving forward with a Zero Emission Vehicle mandate by 2035. Across passenger vehicles, commercial transport, and off-highway machinery, engineers are now tasked with delivering measurable carbon reduction using a combination of electrification, advanced internal combustion engines (ICE) and fuel innovation without compromising safety, durability or performance.
Anderson, Todd
Fuel adulteration affects operating costs, vehicle efficiency, and air pollution. Published estimates suggest it accounts for at least 10% of global sales. The Brazilian National Petroleum Agency (ANP) reported noncompliance in about 23% of inspections in 2023, including 4.3% confirmed adulteration. Quality verification requires laboratory equipment, and sensor-based approaches are often inaccessible to end consumers. This article proposes a sensorless (software-only) method that detects water adulteration in hydrated ethanol from standard Onboard Diagnostics (OBD) data using supervised machine learning, enabling on-vehicle fuel quality monitoring without additional hardware. The proposed approach is evaluated on real-world driving data from two production vehicles with three water adulteration levels in hydrated ethanol (0.0%, 2.5%, and 5.0%), achieving 84.85%–95.85% multiclass classification accuracy. These results indicate that software-only, OBD-based monitoring can provide a practical solution for in-use fuel quality control.
Marchezan, Andre RicardoGiesbrecht, Mateus
The transportation system is one major catalyst to urban ecological imbalance. In developing countries, two-wheelers are considered a major mode of urban personal transportation because of their compactness, easy maneuver in heavy traffic and good fuel efficiency. In India, middle and lower middle-class people prefer to choose two wheelers, and these vehicles are dominantly fuelled by gasoline. Although, the energy consumption by a two-wheeler is comparatively less than that of a four-wheeler, they use about 60% of the nation’s petroleum for on-road vehicles and the impact on urban air quality and climatic change is significantly high. This high proportion of gasoline utilization and emission contribution by two wheelers in cities demand greater attention to improve urban air quality and near-term energy sustainability. Electrification of two-wheelers through the application of a plug-in hybrid idea is a promising solution. A plug-in hybrid motorbike was developed by putting forth a novel drive technique, which demonstrated the advantages of reducing greenhouse gas emissions and using less fuel. The experimental investigation reveals noticeable petroleum fuel savings and greenhouse emission reduction. Through the installation of a hub motor in the rear wheel, the dynamic behaviour of the prototype was examined and observed marginal changes in ride parameters. A cost-benefit analysis was also performed to estimate the payback period for the additional cost incurred.
Kannan, PrashanthShaik, AmjadTalluri, Srinivasa Rao
The growing awareness about sustainability and environmental concerns are accelerating the adoption of electric vehicles. They play a promising role due to their potential to significantly reduce greenhouse gas emissions, improve air quality and lessen reliance on fossil fuels. However, one of the primary concerns for potential buyers is the charging process and infrastructure. Traditional wired charging systems for electric vehicles face limitations such as user inconvenience, wear and tear of connectors and challenges in automation. A wireless electric vehicle charging offers more user-friendly, automated and contactless method by eliminating the need for physical connectors. However, wireless inductive charging suffers from relatively low efficiency due to higher energy losses. Whereas resonant coupling significantly improves efficiency by using electromagnetic resonance to transfer power more effectively over short distances. This paper mainly focuses on design and implementation of a resonant coupling system using series capacitance for achieving resonance, instead of a traditional frequency oscillator. This approach simplifies the circuitry and has shown promising results in maintaining high efficiency. Investigations have been carried out by aligning the transmitter and receiver coils at different distances and load conditions. In the proposal model, resonant wireless power transfer precisely tunes the transmitter and receiver coils to resonate at a shared frequency of 60 kHz, minimising inductive losses and achieving efficiencies of up to 89.74%. The findings showed the potential for resonant wireless power transfer systems to support the next generation of electric vehicle infrastructure. This paper also presents a review on various wireless electric vehicle charging approaches.
Shaik, AmjadGudipati, Ravi Sai HemanthB, Vikranth ReddyAnudeep, D B S SVarshith, Dasari
As the air pollution level rises around the globe, the need for alternative sources of energy increases, and this need applies to automotive industry also. Commercial vehicles are one of the major sources of air pollution around the world as they have impactful applicability in our day to day life. With growing advancement in mobility solutions, commercial vehicles are undergoing transformation to improve efficiency, safety and performance. One of the emerging technologies is of torque vectoring which is a concept used to provide better traction and stability to the vehicle in different driving conditions and used in the vehicle having multi motor configuration. Advance torque vectoring concept coupled with electric motor can react to dynamic driving conditions by providing instant torque. The concept of torque vectoring can be useful for heavy commercial vehicles used in off-road applications such as mining because torque vectoring helps in better weight management, cornering stability, and better drivability on different road surface conditions. Torque vectoring improves overall dynamics of the vehicle to provide better traction and improving maneuverability. This paper discusses different configurations for electric motor placement to achieve maximum potential for torque vectoring for a multi axle heavy commercial electric vehicle used in off-road applications. An overview of torque vectoring control approach used for this study is also explained in this paper. Different configurations were studied by varying the number and placement of motors on both the rear axle. These configurations are analyzed by running the simulation in the Simulink-Trucksim co-simulation environment. The simulation data is further analyzed on different parameters like steering angle, yaw rate, and torque distribution by individual motors to decide the best configuration for the vehicle to reach maximum potential of torque vectoring.
Agarwal, PranjalChaudhari, GiteshGangad, VikasPenta, Amar
This comprehensive research presents an in-depth analysis of communication protocols essential for implementing fast charging systems in India's rapidly expanding electric two-wheeler and three-wheeler market. As India witnesses unprecedented growth in electric mobility, with two-wheelers representing over 95% of current EV sales, the establishment of standardized, secure, and efficient charging protocols becomes paramount for widespread adoption. This study examines the current landscape of AC charging methodologies, evaluates the technical and economic feasibility of DC fast charging implementation, and provides detailed comparative analysis of existing international standards including IS 17017-25, IS 17017-31, ChaoJi, and CCS 2.0. The research concludes with strategic recommendations for developing cyber-secure, cost-effective charging infrastructure specifically tailored to meet India's unique market requirements and operational constraints.
Uthaman, SreekumarMulay, Abhijit B
Road transport contributes 12% of India’s energy-related Carbon Dioxide (CO2) emissions. It is one of the major source of air pollution in urban area. These vehicle related emissions has increased more than three times since 2000 which is mainly driven by rapid urbanization and the growing demand for private vehicles. If there is no shift away from fossil to renewables, climate change intensity and air quality challenges will increase. Among sustainable alternatives, electric vehicles (EVs) have emerged as a promising solution. However, a comprehensive understanding of their environmental performance, particularly in the Indian context, is essential for informed decision-making. This study employs a Life Cycle Assessment (LCA) method to evaluate the environmental consequences of typical passenger vehicle with an gasoline/diesel powered vehicle compared to its EV powertrain covering Cradle-to-Grave life cycle phases. Key life cycle stages—manufacturing, transportation, distribution, maintenance, and end-of-life—are analyzed using real-world data wherever feasible. To capture the evolving energy landscape, the study incorporates India’s projected grid evolution, considering increased renewable energy adoption in 2025, 2030, and 2040 to evaluate use phase impacts for EVs. The findings reveal that EVs demonstrate 14–38% lower CO2 eq. emissions compared to ICE over 150,000 km vehicle lifetime which is subject to pace of grid decarburization and related policy implementation. The study is further extended to cover scenarios with use of 50% & 100% use of solar energy for charging the vehicle which further reduces CO2 eq. emissions up to 61% and to covers other impact categories for all the scenarios. The analysis also identifies a break-even point, after which EVs deliver superior environmental performance compared to their diesel counterparts. The study clearly emphasizes environmental benefits of EVs and highlights the crucial role of renewable energy integration and supportive policy frameworks in effective decarburization. By presenting a robust evaluation, it emphasizes the extensive potential of EVs in advancing India’s sustainable mobility goals and clearly define the significance of accelerating the transition toward greener transportation systems.
Sonawane, NayanSathaye, AsmitaGode, AbhishekDeshpande, AshishShinde, HarshavardhanKothe, Anjali
Air pollution is profligate becoming a serious worldwide problem with the increasing population and its subsequent demands. Diesel, Gasoline, Natural Gas, Propane, etc., are some of the traditional fuels used in the power generation sectors. Diesel fuel, popularly utilized for backup power in critical operations, is valued for its swift activation time. This makes diesel generators a preferred choice for commercial properties and hospitals requiring reliable emergency power. Moreover, natural gas, distributed through local utility grids, provides a convenient and readily available fuel source for generators, eliminating the need for on-site fuel storage. On the other hand, CPCB has instructed to modify the emission regulations for genset engines for decarbonization and development clean fuel. The change from CPCB II to CPCB IV+ standard shows the commitment of the Indian government towards environmental sustainability and COP26. Pondering to the stringent emission norms, researchers are exploring various alternate fuels. This has resulted in increased usage of hydrogen as fuel for Internal Combustion Engines (ICE). Leapfrog to hydrogen ICE will take time for the technology and infrastructure to mature, therefore Hydrogen enriched Compressed natural gas (HCNG) is an intermediate solution for de-carbonisation of ICE. HCNG blends take benefit of the unique combustion properties of hydrogen and at the same time reduce the demand for pure hydrogen. HCNG can take advantage of existing investment in natural gas infrastructure and also has much higher volumetric energy storage density than pure hydrogen. In this study, an in-use multi-cylinder NG operated CPCB II compliant Genset engine was assessed with various HCNG fuel blends. The main objective of the study was to analysis the combustion dynamics and to evaluate the effect of 25HCNG and 30HCNG on the genset engine without major modification in Hardware. The study also draws focus on the combustion parameter variations with higher HCNG blend induction in the engine. With the usage of HCNG the CO, HC pollutants reduce by around 26-46% keeping similar trend of NOx. This approach can make HCNG a probable candidate to reduce emissions from genset engines.
Bandyopadhyay, DebjyotiSutar, Prasanna SDhar, Rit PrasadSonawane, Shailesh BalkrishnaRairikar, Sandeep DThipse, Sukrut SSingh, SauhardMishra, Sumit KumarBera, TapanBadhe, RajeshTule, ShubhamAghav, YogeshLakshminarasimhan, Krishna
In densely populated urban environments, fuel retail outlets represent sources of Volatile Organic Compounds (VOCs), particularly benzene, toluene, and xylene. These emissions occur during various operations including storage tank filling, underground storage, and vehicle refuelling at retail outlets. The contribution of VOC by fuel distribution infrastructure to urban VOC pollution has been adequately addressed by oil marketing companies (OMCs) by the installation of vapor recovery system which is deployed for the comprehensive capture of fugitive emissions. This study employed a novel approach at an OMC Retail Outlet in Delhi, to evaluate benzene concentrations with different operational case studies. The methodology integrated continuous ambient air monitoring system equipped with VOC analyser of Gas Chromatography – Photo Ionization Detector (GC-PID) technology alongside targeted forecourt measurements with handheld PID instrument. Benzene emissions during peak and off-peak hours, vehicle throughput, fuel sales volume, and operational activities are studied. The results demonstrated that with VRS implementation, average concentrations remained below OSHA's permissible exposure limit (1000 ppb), though maximum values periodically spiked during high-traffic periods and underground tank filling operations. Temperature variations (8-21°C), traffic density, vehicle idling time, and operational practices were identified as critical determinants of benzene concentrations. With VRS system, benzene limits are within the 15-minute Short-Term Exposure Limit (STEL) values, ambient levels occasionally exceeded National Ambient Air Quality Standards (1.567 ppb) during cooler conditions with reduced atmospheric dispersion. This case study addresses a critical finding by quantifying VOC emissions in real-world retail outlet operating conditions, establishing that properly implemented vapor recovery technology significantly reduces occupational exposure to further minimize both worker exposure and environmental emissions from fuel retail infrastructure.
Mayeen, HafizAhuja, MuskanKalita, MrinmoyKumar, PrashantSithananthan, MArora, Ajay
To conduct RDE (Real-Drive Emission) test on CEV (Construction Equipment Vehicle), the first step is to study the requirements set forth in the regulation [1, 2] for data collection, post-processing of data and emission calculation along with certain requirements for vehicle operation. Conducting tests on CEV machines poses a different set of challenges compared to on-road vehicles, the major one being the placement of PEMS (Portable Emission Measurement Equipment) on the machine under test. No singular method or mechanism can be specified to suit all types of machinery, although certain guidelines can be set for best practices. The requirement of running the machine on an actual duty cycle or a reference duty cycle requires a thorough study of the intended machine operation and also awareness on the multi-functionality setups offered for such machines by manufacturers, before deciding on a duty cycle to run during actual emission testing. Measurement of emission components such as Carbon Monoxide (CO), Total Hydrocarbons (THC), Nitrogen Oxides (NOx) and Carbon Dioxide (CO2) is required along with Exhaust flow and ECU parameters like engine speed, torque (Actual, Friction, Reference), fuel flow and coolant temperature are required for conducting a valid test. Exploring the impact on emission values of different machine applications, machine duty cycles, environmental and geographical conditions is also of utmost importance to ensure robust engine calibration which will meet future conformity limits irrespective of these factors. Tests on same CEV machinery within same geographical and ambient conditions but under different duty cycle may have variation in emission results [3], this study will delve deeper into this impact of duty cycle on emission value.
Chauhan, PratyushKulkarni, S DMore, ManojJoshi, Monal Vishwas
Environmental pollution is one of the growing concerns of our society. As vehicle emissions are a major contributor to air pollution, emission control is a primary goal of the Automotive industry. Vehicle emissions are higher due to improper combustion, which leads to toxic gases being generated from the exhaust system. Unburnt fuel is one of the leading causes of toxic pollutants such as Carbon Monoxide, Nitric Oxides (NOx) and Hydrocarbons. The catalytic converter converts these gases into less toxic substances such as Carbon Dioxide, Nitrogen, and water vapor. The catalytic converter performs efficiently after reaching its “Light Off” temperature, after which the catalyst becomes active. Hence, elevated temperature of the exhaust gases aids in efficient conversion. Presently, the gases from the exhaust system are approximately at a temperature of 300°C-600°C. This paper outlines the concept of a Peltier (Thermoelectric) Module - based system, which helps maintain the high temperature of the exhaust gases prior to entering the catalytic converter. Peltier Modules are thermoelectric devices well-known for their usage in heating/cooling applications. The proposed system includes a chamber in which the Peltier Module is embedded. As the gases flow through the chamber, the embedded Peltier Module, which is powered by the battery, increases the temperature inside the chamber. Therefore, with this concept, the components required to heat the catalytic converter could be potentially reduced, since the exhaust gases will be maintained at the targeted temperature required for better emission control. Moreover, the Peltier Module is also known to be used for electricity generation. Consequently, by generating electricity through heat utilization on the surface of the chamber, we provide an added benefit of this proposed concept. This can be achieved by mounting the Peltier Module on the hot surface of the chamber. The other side of the Peltier Module is exposed to ambient air and thereby a potential difference is created through the Seebeck Effect.
Venkateshwaran, AishwaryaSoodlu, ShashikiranM, Mathaiyan
This study investigates the concentrations of PM2.5 and PM10 inside an automobile under real-world driving conditions, one of the most polluted cities globally. India faces severe air pollution challenges in many cities, including Delhi, which are consistently ranking among the most polluted cities in the world. Major contributors to this pollution include vehicular emissions, industrial activities, construction dust, and biomass burning. Exposure to PM2.5 and PM10 has been linked to numerous adverse health effects, including respiratory and cardiovascular diseases, aggravated asthma, decreased lung function, and premature mortality. PM2.5 particles, being smaller, can penetrate deeper into the lungs and even enter the bloodstream, causing more severe health issues. In big cities like New Delhi, long driving times exacerbate exposure to these pollutants, as commuters spend extended periods in traffic. Measurements were taken both inside and outside the vehicle to assess the real-world impact of various scenarios encountered viz. doors/windows opening e.g. at tolls, stepping in/out from car etc. The above scenarios were tested with a PM2.5 filter installed in the car. The results indicate significant variations in particulate matter concentrations in different scenarios, highlighting the importance efficient in-vehicle air quality management. This research provides valuable insights into the effectiveness of PM2.5 filters and the potential health implications for commuters in severely polluted urban environments.
Gupta, RajatPimpalkar, AnkitPatel, AbhishekKumar, ShubhamJoshi, RishiKumar, Mukesh
Validation of hydrogen-fuelled internal combustion engine (H2 ICE) is critical to assess its feasibility as sustainable transportation with zero carbon emissions. This experimental analysis conducted on Ashok Leyland’s 6cylinder 2V engine to evaluate the engine performance & durability with hydrogen fuel. Combustion behaviour of hydrogen ICE needs to be closely monitored during continuous operation of validation testing, due to its unique properties compared to other conventional fuels. During engine run, a pre-ignition source can cause knock event leading to instant failure of critical parts like piston assembly, spark plug, liner, valves & cylinder head. Also, hotspots inside IMF leads to backfire affecting the air intake & fuel injection assembly. This study emphasizes the significance of precise instrumentation of thermocouples across engine on cylinder head, intake manifold & exhaust manifold, to detect performance detoriation and combustion abnormalities causing knocking & backfire. Crankcase ventilation system design plays a critical role in evacuating the blowby gas from engine block. This paper explains methodology to measure the moisture condensation from blowby gas, as it leads to oil emulsification. Experimental data shows variation in inlet manifold air temperature directly impacts engine power as H2 ICE operates at higher stoichiometric ratio. Increase in air intake temperature from turbo compressor out is a result of barometric temperature and pressure variation. This measurement is critical to understand the engine performance variation in real-time operating condition. Hence validation of H2 ICE necessitates a specialized instrumentation during testing to monitor the performance parameters and hardware detoriation. This research provides critical insights into the procedural adaptations required for H2 ICE testing and validation by integrating frugal instrumentation with experimental analysis. This study offers a robust framework for assessing engine performance, reducing operational risks, and ensuring test results reliability. These findings contribute to the design & development of hydrogen-fuelled engines, facilitating their adoption as a sustainable alternative for transportation while addressing durability, emissions, and regulatory compliance challenges.
Vasudevan, SindhujaJ, Narayana ReddyBolar, Yogesh GaneshPandey, SunilN, HarishN R, VaratharajKarthikeyan, KKumar D, Kishore
Air pollution from vehicle exhaust emissions is a growing issue in major cities around the world. Hydrogen is a clean and carbon-free fuel that presents a promising alternative to the fossil fuels. However, despite its environmental advantages, hydrogen internal combustion engines still produce some nitrogen oxides as a by-product due to high combustion temperatures. This study investigates the effectiveness of current exhaust after-treatment technologies designed to reduce NOx emissions in hydrogen-powered engines. A comparative analysis is conducted between the conventional urea-based selective catalytic reduction used in diesel engines and emerging hydrogen-based selective catalytic reduction technologies for hydrogen engines. The analysis is performed using CFD simulation in ANSYS Fluent, focusing on NOx reduction efficiency and other operational parameters. The results provide valuable insights into the feasibility and effectiveness of hydrogen SCR in achieving reduced NOx emissions, and this technology also eliminates the current urea storage and dosing arrangement, as vehicle-on-board available hydrogen can be used for NOx reduction in hydrogen-based SCR technology.
Kashyap, KeshavKhandagale, AnupPetale, Mahendra
This paper is to introduce a new catalyst family in gasoline aftertreatment. The very well-known three-way catalysts effectively reduce the main emission components resulting from the combustion process in the engine, namely THC, CO, and NOx. The reduction of these harmful emissions is the main goal of emission legislation such as Bharat VI to increase air quality significantly, especially in urban areas. Indeed, it has been shown that under certain operating conditions, three-way catalysts may produce toxic NH3 and the greenhouse gas N2O, which are both very unwanted emissions. In a self-committed approach, OEMs could want to minimize these noxious pollutants, especially if this can be done with no architecture change, namely without additional underfloor catalyst. In most Bharat VI gasoline aftertreatment system architectures, significant amounts of NH3 occur in two phases of vehicle driving: situations with the catalyst temperature below light-off, which appear after cold start or at low-speed urban driving and hot, high mass flow phases. In this paper, we will compare several approaches to reduce NH3 starting with an existing gasoline technology, diesel technologies modified to gasoline conditions and the especially developed novel gasoline Secondary Emission Treatment (SET) catalyst, providing both ammonia abatement and underfloor three-way functionality. SET is the combination addressing both the cold start phase and hot driving conditions. In addition, it fulfills the role of an underfloor three-way catalyst, responsible for CO and NOx hot phase treatment.
Kuhn, SebastianMagar, AvinashKogel, JuliusLahousse, Christophe
The transportation and mobility sector are undergoing a profound transformation, with a growing emphasis on sustainability and minimizing the environmental impact of transportation. Among the most significant trends is the transition to electric vehicles (EVs) in the form of Battery and Fuel cell, which produce zero emissions without any harmful gases release in nature. This review highlights several infrastructure-related issues and critical factors that could drive India's transportation sector toward adopting electric vehicles. It also delves into the fundamental understanding of e-mobility, shedding light on the daily challenges and barriers it faces. Furthermore, the study explores research aspects, including the strategies, methods, and tools used for electric vehicles to complete the research on Battery electric vehicles (BEV) and also comparative analysis with Fuel cell vehicles (FCVs). The shift BEVs has been driven by decreasing battery costs and advancements in charging infrastructure, making EVs a more feasible choice. The review also examines the Indian government's approach to e-mobility and compares India's infrastructure with that of developed nations to identify key factors. Finally, it suggests major strategies and solutions to address challenges facing the Indian automobile sector. Collaboration between automotive industry stakeholders and government entities will be essential to overcome these challenges and foster EV adoption. This will ultimately help reduce carbon emissions and air pollution. Taken together, this review article will help in shaping a future of sustainable, efficient, and interconnected mobility.
Kumar, Dr. Vijay Bhooshan
The Indian automobile industry is experiencing a significant shift, propelled by environmental necessities and national climate obligations set at the CoP26 summit, aiming for a 45% decrease in CO₂ emissions by 2030 and reaching carbon neutrality by 2070 [1]. Transportation continues to be a significant source of air pollution; consequently, India is enhancing its regulatory frameworks with BS VI Stage 2 regulations, CAFE Phase III norms set for 2027, and CAFE Phase IV by 2032 [2]. Furthermore, the transition from MIDC to WLTP driving cycle is meant to increase the accuracy of the efficiency and emissions assessments [2]. To comply to these upcoming regulations, the automotive industry is moving toward producing high efficiency engines in India. A naturally aspirated (NA) 1.5L, 4-cylinder inline gasoline engine was selected from Indian market for this study. Maximum Brake Thermal Efficiency (BTE) of this engine is around 37%. Assessment of new technologies were performed by implementing them stepwise to see the impact on BTE. A well calibrated 1D GT-SUITE model was considered from FEV database to perform the simulation-based approach to increase the BTE by improving the stroke/bore (s/B) ratio, increasing the compression ratio, implementing Atkinson cycle with variable valve timing (VVT) / variable valve lift (VVL) optimization, and charge motion refinement for optimal in-cylinder combustion. Low temperature cooled EGR (TEGR < 70°C) and pre-catalyst pick-up distributed EGR strategies were simulated to improve the combustion stability and pumping loss for BTE improvement. Friction losses were further minimized by implementing the polished surfaces, electrification of auxiliary components, and other advanced surface treatments. Advanced technologies including Dual Port Fuel Injection (Dual PFI) system, high energy ignition system with thermal swing coatings, and system designed to operate with highly diluted mixture are required to achieve maximum BTE. These technologies would also be explored in this study. This paper also covers the rivals' restrictions put on engine geometry and number of cylinders concerning possible max. BTE level with which the engine can achieve. With the completed study, the efficiency step walk document indicated BTE improvement from each technology step to achieve a target max. BTE for the engine.
Garg, ShivamFischer, MarcusEmran, AshrafJagodzinski, BartoschFranzke, Bjoern
Emission Regulations for NRMM in India have evolved significantly over past two decades. India has progressively adopted stricter standards to align with best practices carried out globally for curbing air pollution. The latest regulations have introduced stringent caps on nitrogen oxides (NOx), and other emission pollutants, ensuring compliance with environmental sustainability goals. Future legislative frameworks are expected to impose even more rigorous emission limits, while incorporating real-world emission monitoring. This will require powertrain manufacturers to integrate advanced after-treatment systems and adopt cleaner combustion technologies to meet compliance standards. To validate compliance with these stringent limits, rigorous testing methodologies are employed. Portable Emission Measurement Systems (PEMS) have become a crucial tool for real-world emission assessment. PEMS technology allows for on-road and field testing of NRMM under actual operating conditions, providing a comprehensive analysis of pollutant levels. The setup consists of advanced gas analyzers and data acquisition systems installed directly on the machinery. These systems continuously measure CO, CO2, nitrogen oxides (NOx), and other emission pollutants, ensuring precise monitoring. The installation involves strategic placement of sensors and exhaust sampling systems, allowing real-time data collection. The testing process involves preconditioning the equipment, executing a predefined test-cycle under operational conditions, and analyzing the collected emission data against regulatory standards. This methodology ensures that emission control strategies are effectively validated in real-world applications. Post-processing of test data is critical for interpreting results and assessing compliance. Advanced data analytics techniques are used to refine raw measurements, filter anomalies, and generate comprehensive emission reports. In this paper, as we go forth, focus has been placed on the real time application of PEMS system for CEV/TREM, covering important points like setup installation, components involved, technology used, test procedure criterion based on emission norms, data accumulation and analysis, report generation, etc. And all this is done using the indigenous state of the art AVL PEMS setup.
Rastogi, AadharGarg, VarunRagot, Nicolas
This paper explores the adaptability and reliability testing methods of electric vehicles under the unique high-temperature and high-humidity climate conditions in Southeast Asia. The focus of the research here is on five key performance evaluation contents, namely reliability driving test, charging performance test, range assessment, air conditioning cooling efficiency, and in-vehicle air quality monitoring. Relying on a meticulously designed experimental plan, standardized testing procedures, and comprehensive data analysis, this paper assesses the performance of electric vehicles under extreme environmental conditions. The research results show that the climate in Southeast Asia poses significant challenges to the battery systems, powertrains, and thermal management systems of electric vehicles. Based on empirical results, some improvement suggestions are made to support the deployment and application of electric vehicles in this region.
Wang, WeijieDeng, TianhaoWu, YilongZang, Haonan
Studies correlate air pollution with an increase in the incidence of respiratory diseases, affecting lung function and raising hospitalization rates. Among the pollutants associated with these diseases, inhalable coarse particulate matter (PM10) and fine particulate matter (PM2.5) stand out. The emission of particulate matter resulting from the wear of brake pads in light vehicles is the second largest source, accounting for approximately 33% of a vehicle’s total emissions. The particulate matter generated during the braking process can be analyzed through its collection in tests conducted on dynamometers, using enclosure and sampling systems. The development of the dynamometer used was based on the braking cycles described in the SAE J2522:2003 standard, whose main objective is to provide comparative data on different friction materials. Given the variations in particulate matter emissions depending on the composition of the brake pads, as reported in the literature, this study presents an analysis of the emissions from two distinct formulations, as well as a comparison of wear parameters and the surface roughness of the pads. The characterization of the particulate matter was carried out using a sampling system in accordance with ISO 9096:2017, with a sampling duct aligned with the flow duct downstream of the enclosure chamber, and particle retention achieved through fiberglass filters. The airflow velocity was controlled to ensure isokinetic transport conditions in the sampling system, adjusting the connected pump to match the probe velocity. The results show that wear was not uniform between the pairs of brake pads, also revealing differences in the chemical composition of the particulate matter according to the different formulations, consistent with what is reported in the literature, but with similar particle concentrations by size.
Catão, Vítor Gustavo GomesMachado, Amanda RibeiroFiorentin, Felipe KleinSilva, João Pedro AnutoBernardino, Lucas GabrielFiorentin, Thiago AntonioCarboni, Andrea Piga
Volatile Organic Compounds (VOCs) generated in the oil transportation process are important precursors for secondary organic aerosols (SOA) and photochemical smog. These emissions have become one of the key environmental constraints in China’s 14th Five-Year Plan. Due to the diversity of oil products, VOC composition varies significantly among different types of oil, such as crude oil and refined oil, making it a critical consideration in the development of pollution control policies and treatment processes for the transportation sector. This study employs gas chromatography with a hydrogen flame ionization detector and mass spectrometry to analyze VOCs emitted from 31 types of crude oil and refined oil samples under simulated transportation and storage conditions. By utilizing multi-source detection and mass spectrometry overlay, along with area normalization spectral analysis, we provide a more accurate breakdown of VOC components from crude oil, asphalt mixtures, gasoline, diesel, aviation kerosene, and naphtha. Special attention is given to the olefin and aromatic hydrocarbon components, which contribute significantly to ozone formation. The research results can provide important basis for the research and design selection of VOCs treatment technology and equipment in the transportation process.
Qiu, ChunxiaXiao, HanZheng, YongrenHe, Zhengbang
Off-Highway Vehicles (OHVs) — including mining trucks, construction machinery, and agricultural equipment — contribute significantly to greenhouse gas (GHG) emissions and local air pollutants due to their dependence on fossil diesel. Achieving sustainable development goals in off-highway sectors requires transitioning toward alternate fuels that can reduce CO₂, NOₓ, and particulate matter (PM) emissions while maintaining performance and reliability. This paper comprehensively evaluates alternate fuels such as biodiesel, renewable diesel, compressed and liquefied natural gas (CNG/LNG), liquefied petroleum gas (LPG), hydrogen, and alcohol-based blends. Using insights from Service Bulletins, fuel standards, and the Worldwide Fuel Charter, it discusses fuel properties, engine compatibility, operational challenges, sustainability impacts, economic feasibility, safety considerations, and regulatory aspects. Case studies of alternate fuel deployment in OHVs illustrate practical challenges and successes. Recommendations are made for fuel selection, system modifications, and future research to support sustainable operation of OHVs.
Mulla, TosifThakur, AnilTripathi, Ashish
The increasing demand for alternative fuels due to environmental concerns has sparked interest in biodiesel as a viable substitute for conventional diesel. Most automotive engines use diesel fuel engines. They contribute a major portion of today’s air pollution, which causes serious health issues including chronic bronchitis, respiratory tract infections, heart diseases, and many more. Greenhouse gases are produced using fossil fuel in the engines and causes global warming. To combat air pollution, we need clean renewable and environmentally friendly fuels. Due to depletion of fossil fuels, it has become necessary to find alternative fuel which are safer for the environment and humankind. One such possible solution is Biodiesel. In present study, series of experiments were carried out on 435cc naturally aspirate DI Diesel engine with port water injection and different blend of Jatropha based Biodiesel. Biodiesel was derived from Jatropha oil, produced using a heterogeneous catalyst. The physical and chemical properties were determined for different blends of Biodiesel specifically JB20, JB30 and JB100 before engine testing. Engine tests were recorded on engine eddy current dynamometer and vehicle emission were recorded on chassis dynamometer to investigate the performance and emission characteristics of different biodiesel blends compared with conventional diesel. Recorded engine test performance infers improvement in observed torque and power. BSFC and Smoke results were comparable on full load and part load conditions. There is reduction in HC, CO raw emission with JB20 and JB30 Biodiesel fuel as compared to conventional Bharat Stage 6 Diesel fuel. Particulate Matter are comparable with all the above fuels. Vehicle mass emission with combination of port water injection and JB20 biodiesel has benefited further to reduce HC & NOx emission to meet Bharat Stage 6 emission norms on Diesel three-wheel vehicle on Indian Driving cycle. These findings highlight the potential of Jatropha biodiesel as a cleaner alternative to conventional diesel.
Bhoite, VikramSyed, KaleemuddinChaudhari, SandipKhairnar, GirishJagtap, PranjalReddy, Kameswar
Cabin air quality plays a crucial role in ensuring passenger comfort, health and driving experience. There have been growing concerns over poor cabin air quality resulting from multiple factors, including infiltration of external pollutants such as particulate matter, volatile organic compounds, emissions from vehicle interior materials, microbial contamination and inadequate ventilation. Therefore, maintaining optimal air quality inside vehicle cabin has become a critical aspect of vehicle climate control systems. Additionally, high humidity levels inside the cabin contribute to mold growth and fogging of windows, further compromising both air quality and visibility. This review explores such factors contributing to poor cabin air quality, where the severity of these issues ranges from mild discomfort and allergic reactions to long-term respiratory ailments. To mitigate these challenges, automotive manufacturers and researchers have implemented various air purification and filtration technologies. High-efficiency particulate air (HEPA) filters and activated carbon filters are widely used to capture fine particles, allergens and gaseous pollutants. Advanced filtration solutions such as ionization, photocatalytic oxidation, UV-based purification and plasma air cleaning technologies have also been developed to neutralize airborne contaminants. The development of smart climate control systems integrated with real-time air quality monitoring system help in regulating ventilation and filter efficiency, based on external and internal conditions. Moreover, material innovations, such as low-emission interior components, contribute to enhancing cabin air quality. This comprehensive review highlights that implementing basic design aspects for cabin air quality will not only improve passenger well-being but also enhance overall vehicle comfort, making it a key consideration in future vehicle design.
Sharma, Shrutika
The internal combustion engine has mechanized the world. Since the early 1900s, it has become a prime source of mechanical power. In modern times, petrol and diesel engine-powered vehicles find wide application in the field of transport and agriculture. However, the progress has resulted in newer problems. Due to the high density of internal combustion engines, the world over has resulted in the severe pollution problem. They are classified as air and noise pollution. Air pollution is caused due to dispersion of emitted from engine exhaust to the atmosphere at different concentration levels. Similarly, the emission of unwanted sound from engine structure, intake and exhaust are the principal sources of noise pollution. Excessive noise can have severe psychological and physiological effects on human beings like hearing loss, muscular and gastric effects and fatigue. In the present problem, we have studied mechanical-induced noise. Mechanical noise refers to noise generated by the vibrating surface of the engine structure, engine components and engine accessories after excitation by reciprocating or rotary engine components. In mechanical noise, sources are as follows. 1 Piston slap 2 Injection system noise 3 Timing gear noise 4 Fuel Injection pump noise 5 Structure noise 6 Oil pan noise In the present study, we are working on the following two engine sources: 1 Fuel Injection Pump 2 Oil Pan These two noise sources were isolated through wooden ducts for an 80KW diesel engine coupled with a hydraulic dynamo-meter at different speeds and load conditions. The results were compared with the overall sound pressure level (SPL).
Goel, ArunkumarMeena, Avadhesh Kumar
During air conditioning operation in automobiles (ICE and EVs), cabin air is predominantly recirculated to reduce heating and cooling loads of occupant space. However, prolonged recirculation of air leads to deteriorated cabin air quality. Simply introducing fresh air to improve air quality is inefficient, as external air conditions are unpredictable and may negatively affect energy consumption as well as cabin interior air quality. Moreover, even in recirculation mode under low ambient conditions where de-humidified air is available outside, energy usage increases due to the dual operation of the electric compressor (e-Compressor) and the Positive Temperature Coefficient (PTC) heater especially in case of Electric Vehicle. In this dual-mode scenario, the e-Compressor maintains a low evaporator temperature for effective air dehumidification, while the PTC heater supplies sensible heating to achieve the desired cabin comfort. In case of ICE vehicle the heater is coolant based and free heat is available whereas in case of EVs it’s a parasitic load on battery. This combination results in higher energy consumption, presenting challenges in optimizing both air quality and energy efficiency in EV climate control systems. This work tries to understand and control overall cabin air quality using plurality of sensors (ambient, humidity, air quality) inside and outside the car and uses, a control mechanism to predict and control air inlet operations to achieve always better cabin air quality with reduced power consumption.
Kumar, SunnyVenu, SantoshRaj, ShivamKhan, Farhan
Single-zone cabin climate control systems have been standard for decades in passenger cars. Looking at the technology trend, which is transitioning from single-zone to multi-zone automatic control systems, it is now possible to provide zonal comfort tailored to the individual requirements of each passenger. In current single-zone climate control systems, maintaining the cabin temperature as stated by the passenger has been straightforward and can be achieved with slight calibration efforts using the present set of parameters and sensors until now. In this work, a multi-zone climate system highlighting the importance of individual calibration parameters in improving cabin comfort when transitioning from a single-zone to a multi-zone climate control system is proposed. As multi-zone climate systems are based on passenger set temperature requests for individual zonal comfort, appropriate controller fine-tuning is challenging when an input is taken from various sensed parameters, including cabin temperature, solar load, ambient temperature, coolant temperature, evaporator outlet temperature, and air quality. It offers valuable insights into the necessary software calibration corrections to ensure optimum zonal comfort for passengers. It is observed that refinement of key parameters enhances passenger comfort and shortens the time required to achieve comfort conditions during the multi-zone calibration process.
Varma, MohitSwarnkar, Sumit KumarBHOSALE, KRISHNAPatil, PrashantSardesai, Suresh
The study emphasizes on detection of different faults and refrigerant leakage as well as performance investigation of automobile air conditioning system for an electric vehicle by varying various operating conditions. A refrigerant leak in an EV isn't just an inconvenience; it's a potential threat to vehicle range and usability, lifespan and health of the expensive battery pack, overall vehicle performance, passenger safety and comfort, component longevity (motor, power electronics), environmental responsibility. Due to the refrigerant leakage, the cooling system performance degrades, and components tend to fail. Because of that this study is focusing on deriving an algorithm to have an early detection of fault and leakage in the vehicle. The performance of the system is predicted for actual conditions of operation encountered by the automobile air conditioning system. The objective of the present work includes predicting the causes and effects of refrigerant leakage in AC system of Electric vehicle, developing numerical simulation model of the air conditioning system and an algorithm to detect different faults and predict the performance with and without leakage which uses the refrigerant R134a. For this purpose, a simulation model and a leak detection algorithm have been developed for a small automobile air conditioning system with R134a refrigerant. The Coefficient of Performance (COP), cooling capacity values are compared for both with and without refrigerant leakage in the AC system. For that, the temperature and pressure values of different points from the simulation model of the AC system are taken and used by the algorithm in stateflow model to detect the leakage in the system. After the complete analysis it has been noticed that the COP of the AC system drops significantly from 4.7 with 0% fault to 3.59 with 66% fault, and cooling capacity drops from 1.398kW with 0% fault to 0.46kW with 66% fault, which indicates the deterioration of the system over time.
Bezbaruah, PujaYadav, AnkitPilakkattu, Deepak
The current work is the second installment of a two-part study designed to understand the impact of high-power cold-start events for plug-in electric vehicles (PHEVs) on tailpipe emissions. In part 1, tailpipe emissions and powertrain signals of a modern PHEV measured over three drive cycles identified that high-power cold-start events generated the highest amounts of gaseous and particulate emissions. The trends in emissions data and powertrain performance were specific to the P2-type hybrid topology used in the study. In this second part of the study, the effects of different PHEV hardware configurations are determined. Specifically, the tailpipe emissions of three production plug-in hybrid vehicles, operated over the US06 drive cycle, are characterized. The approach compared the tailpipe emissions of the test vehicles on the basis of the hybrid topologies and corresponding engine operational characteristics during a high-power cold-start event. Analysis of test results showed differences in the engine startup strategy for different hybrid configurations. Time-resolved tailpipe emissions of CO, NOx, total unburned hydrocarbons (THC), and particulates varied depending on the engine load during the cold-start. The likelihood of experiencing a high-power cold-start on the US06 was dependent on powertrain characteristics including e-motor size and battery state of charge. The results are discussed in detail in terms of the specific regulated air pollutants and the impact of the startup strategy implemented. Lastly, vehicle dynamics including drag and inertia forces were found to be much lower for the smaller power-split hybrid test vehicle, which reduced its propensity to experience a high-power cold-start event. The findings provide insights on how to manage high-power cold-start events in relation to the type of hybrid configuration utilized as well as their capability to meet upcoming emissions targets.
Chakrapani, VarunO’Donnell, RyanFataouraie, MohammadWooldridge, Margaret
The California Air Resources Board (CARB) and the United States Environmental Protection Agency (US EPA) have recently introduced targets for tailpipe emissions during high-power cold-start conditions for plug-in hybrid electric vehicles (PHEVs). However, the performance characteristics of hybrid powertrains and the effectiveness of cold-start strategies in PHEVs are not well known. In this two-part study, the performance of a production PHEV is examined with the objective of quantifying the impact of high-power cold-start events on overall tailpipe emissions. High temporal fidelity data of powertrain performance and tailpipe emissions generated during cold-start events for various driving conditions are presented for the first time. The selected P2 hybrid vehicle was tested using (i) the European Real Driving Emissions (RDE) test, (ii) the US06 (Supplemental Federal Test Procedure), and (iii) a custom drive cycle developed for this study. Results show that driving conditions leading to the events vary significantly between the drive cycles. Demand for high vehicle speed and/or high traction power triggered cold-start events despite the high battery state of charge. The results are discussed in detail in terms of the specific regulated air pollutants and powertrain performance monitored in the 50-seconds window following each cold-start event. In the companion study, tailpipe emissions characteristics and engine start strategies are compared across multiple hybrid topologies during a high-power cold-start event. The results from both studies provide valuable new information to enable design of hybrid powertrains for future PHEVs that meet the upcoming cold-start emissions regulations.
Chakrapani, VarunO’Donnell, RyanFatouraie, MohammadWooldridge, Margaret
Air pollution is a significant long-term public health issue, with on-road traffic emissions being a primary contributor, especially in urban areas. Remote emission sensing (RES) is an innovative method for large-scale monitoring of vehicle emissions. It not only enables accurate detection of pollutants from vehicles under real-world driving conditions but also offers actionable insights to optimize engine performance. The point sampling-based RES technique involves sampling the vehicle exhaust plume along the roadside with a sampling line and using exhaust analyzers. In this method, the sampling line is placed alongside the road for sample extraction. Thus, the sampling position and knowledge regarding the spread of the exhaust plumes are crucial. Other modern RES systems utilize laser absorption spectroscopy to measure the pollutants in vehicle exhaust. For accurate absorption measurements, the laser’s height must align with the height of the exhaust plume, and the absorption length must be known. In this work, we present a gas density Schlieren imaging sensor (GDSIS) system designed to visually capture, quantitatively analyze, and reconstruct the density fields of exhaust plumes from category L-vehicles. By analyzing the density fields, we can pinpoint the location of the highest density within the exhaust plume. This information indicates the ideal height for positioning sampling lines and lasers used in RES systems. Identifying this ideal height can enhance the efficiency and capture rate of RES systems while also helping to detect engine inefficiencies that can negatively affect performance and increase emissions. Moreover, emission patterns can inform engine calibration or maintenance schedules, which helps optimize fuel consumption and engine response. The performance of the GDSIS system in both laboratory settings with controlled gas flows and on the road with L-vehicles during emissions measurement campaigns is evaluated.
Imtiaz, Hafiz HashimLiu, YingjieSchaffer, PaulKupper, MartinBergmann, Alexander
The effective reduction of particulate emissions from modern vehicles has shifted the focus toward emissions from tire wear, brake wear, road surface wear, and re-suspended particulate emissions. To meet future EU air quality standards and even stricter WHO targets for PM2.5, a reduction in non-exhaust particulate (NEP) emissions seems to be essential. For this reason, the EURO 7 emissions regulation contains limits for PM and PN emissions from brakes and tire abrasion. Graz University of Technology develops test methods, simulation tools and evaluates technologies for the reduction of brake wear particles and is involved in and leads several international research projects on this topic. The results are applied in emission models such as HBEFA (Handbook on Emission Factors). In this paper, we present our brake emission simulation approach, which calculates the power at the wheels and mechanical brakes, as well as corresponding rotational speeds for vehicles using longitudinal dynamics equations integrated in the simulation tool PHEM (Passenger Car and Heavy duty Emission Model). This simulation model is applicable for both LDV and HDV in the case of NEP. The brake wear emissions, including PM10, PM2.5, PN23, and PN10, are interpolated from characteristic brake emission curves that depend on braking power and vehicle speed. These characteristic curves are generated from a database containing data from literature, partners, and measurement campaigns conducted by our team. The model also considers brake energy recuperation in hybrid and battery electric vehicles, as well as the use of retarders in heavy-duty vehicles The physical approach enables the simulation of all propulsion systems in various driving cycles for all vehicle categories. Furthermore, we will present the projected development of PM and PN emissions for European PC, LDV and HDV traffic through 2050, considering different propulsion technology scenarios including also exhaust particle emissions for comparison.
Landl, LukasKetan, EnisHausberger, StefanDippold, Martin
The growing demand for improved air quality and reduced impact on human health along with progress in vehicle electrification has led to an increased focus on accurate Emission Factors (EFs) for non-exhaust emission sources, like tyres. Tyre wear arises through mechanical and thermal processes owing to the interaction with the road surface, generating Tyre Road Wear Particles (TRWP) composed of rubber polymers, fillers, and road particles. This research aims to establish precise TRWP airborne EFs for real-world conditions, emphasizing in an efficient collection system to generate accurate PM10 and PM2.5 EFs from passenger car tyres. Particle generation replicates typical driving on asphalt road for a wide selection of tyres (different manufacturers, price ranges, fuel economy rating). Factors such as tyre load, speed and vehicle acceleration are also considered to cover various driving characteristics. The collection phase focuses on separating tyre wear particles from potential contaminants, such as brake particles and other road particles, while maintaining high collection efficiency. To achieve this, the collection system is designed and optimized using Computational Fluid Dynamics (CFD) simulations to define the exact positioning, geometry and flow characteristics of the sampling nozzle, maximize particle capture and limit any loss for particles ranging in diameter from 10 nm to 10 μm. An advanced setup, incorporating a full-enclosure around the brake system and cleaning of a closed, controlled test track, are used to further prevent cross-contamination from other particle sources. Appropriate instrumentation is used to characterize the collected particles, employing Electrical Low-Pressure Impactors (ELPI) for particle number and size distribution, and gravimetric method and subsequent analyses (ICP-MS, GC-MS, and pyrolysis GC/MS) to quantify metal, organic components, distinguish TRWP from other sources and calculate the PM10 and PM2.5 EFs. Despite limitations in fully replicating real-world conditions and eliminating contaminants, this work fills critical data gaps, supporting more accurate emission inventories.
Kontses, DimitriosDimaratos, AthanasiosKaimakamis, ThomasVizvizis, GeorgeOuzounis, RafailKoutsokeras, OdysseasSamaras, Zissis
Dual-fuel combustion is emerging as a promising solution to address the growing focus on maritime decarbonization, because it is adaptable and needs minimal system modifications. However, natural gas as an alternative fuel must deal with the issue of methane slip, because methane has greater global warming potential than CO2. Conventional aftertreatment systems may incorporate a methane oxidation catalyst to mitigate methane emissions, but effective methane oxidation requires high temperatures of approximately 400 °C. Therefore, exhaust thermal management (ETM) is crucial for maintaining high exhaust gas temperature (EGT) and ensuring conversion efficiency. This study investigates the effectiveness of fully variable valve actuation (VVA), including early exhaust valve opening (EEVO) and early intake valve closing (EIVC), along with lambda control via wastegate control. Each strategy’s effect on exhaust gas temperature is evaluated, while considering potential trade-offs with efficiency. The research uses a model-based approach, simulating a state-of-the-art, six-cylinder natural gas/diesel dual-fuel marine engine (Wärtsilä 6L20 DF), equipped with a two-stage turbocharger with wastegates. Numerical simulations are conducted using a one-dimensional (1D) engine model within GT-Suite across two different load conditions. The model is validated using baseline valve timings and a comprehensive dataset of experimental data. Results indicate that all three strategies can contribute to EGT elevation. EEVO raises EGT by 73 K, but incurs a 3.85% reduction in brake thermal efficiency (BTE). EIVC achieves a substantial EGT increase of 122.7 K at medium load, with a slight BTE improvement of 0.4%. Wastegate lambda control elevates EGT by 91.5 K at low load, exhibiting a negligible BTE impact. Thus, VVA-based ETM and lambda control enable rapid warm-up of exhaust aftertreatment systems (EATS) in large-bore engines with a minor efficiency penalty. This helps compliance with stricter emission regulations which contribute to maritime decarbonization, eventually enhancing air quality and the maritime ecosystem.
Soleimani, AmirKim, JeyoungAxelsson, MartinHyvonen, JariMikulski, Maciej
Tire and road wear particles (TRWP) have emerged as air quality hazardous matters and significant sources of airborne microplastic pollution, contributing to environmental and human health concerns. Regulatory initiatives, such as the Euro 7 standards, emphasize the urgent need for standardized methodologies to quantify TRWP emissions accurately. Despite advancements in measuring tire abrasion rates, critical gaps persist in the characterization of airborne TRWP, particularly regarding the influence of collection system design and influencing parameters on measurement accuracy and repeatability. This study addresses these challenges by designing a controlled methodological framework that aims to minimize the influencing effects and ensure comparability in TRWP emission quantification results. At the German Aerospace Center (DLR) dynamometer testbench in Stuttgart, Germany, a methodical framework was established to ensure the repeatability and comparability of TRWP measurements, incorporating standardized tire testing conditions and particulate matter sampling methodologies. The results indicated that the DLR® housing-based system with an encapsulated tire exhibited higher particle concentrations in fine and ultrafine fractions compared to the nozzle-based system. Statistical analyses following ISO standards confirmed that the DLR® housing system demonstrated higher measurement consistency, with lower deviations in repeated tests. In contrast, the nozzle system showed higher deviations, particularly in the PM10 fraction (i.e., particles with aerodynamic diameter less than 10 μm), suggesting potential particle losses and lower collection efficiency. These findings emphasize the importance of designing measurement methodologies that minimize the influence of external factors and improve the repeatability of TRWP characterization. By establishing a standardized and comparable framework that isolates tire-road interaction effects from environmental and surface variability, this study enhances the accuracy of TRWP emission measurements. The proposed methodology aims to serve as a robust foundation for regulatory frameworks, offering valuable insights into the optimization of current TRWP measurement techniques.
Celenlioglu, Melis SerenEpple, FabiusReijrink, NinaLöber, ManuelReiland, SvenVecchi, RobertaPhilipps, Franz
This article details the experimental and testing activities of the EU project AeroSolfd, with a particular focus on the project's efforts to reduce combustion-based nanoparticle emissions in exhaust gases for the European fleet of vehicles by developing a GPF retrofit solution. The technical activities undertaken the process of developing such a retrofit are examined in this article. The findings illustrate the viability of reducing nanoparticle levels in gasoline-powered vehicles with the utilization of appropriate GPFs. For this purpose, in addition to a fleet, four vehicles were examined in great detail and underwent the process of obtaining component approval for the particulate filter. The vehicles were measured in a preliminary state, then following the installation of the GPF, and subsequently after several months of continuous field operation. A total of four vehicles were selected for evaluation as a representative subgroup of a larger test fleet of vehicles in the project. These four vehicles were subjected to a series of assessments, including measuring the emissions on a chassis roller test bench and in real-drive experiments with portable emission measurement equipment. The gaseous and nanoparticle emissions were examined in each of these two test cases, and the variants with and without a particle filter as well as the variants before and after the endurance run. Preliminary findings indicate that the retrofitting of gasoline vehicles with minimal modifications can yield notable benefits besides the reduction in air pollution, particularly in the form of nanoparticles.
Engelmann, DaniloMayer, AndreasComte, PierreRubino, LaurettaLarsen, Lars
Air quality is an increasing concern, particularly in densely populated urban areas. Indeed, large European cities have seen pollutant concentrations exceed World Health Organization thresholds, with a significant portion of NOx emissions originating from road transportation. Studies have shown that less than five percent of the vehicle fleet, often including vehicles with defective after-treatment systems, is responsible for a disproportionate share of these emissions. This highlights the importance of not solely relying on the gradual renewal of vehicle fleets to mitigate health risks associated with air pollution. This research, funded by the French Agency for the Ecological Transition (ADEME), introduces an experimental methodology aimed at controlling emissions from vehicles already in circulation. Aramis Group, a European specialist of refurbishment and online sales of used cars, provided several refurbished used vehicles for testing, directly taken from its workflow. These vehicles were tested using REAL-e, a lightweight Smart Emission Measurement System developed by IFP Energies nouvelles, along a short round trip near the refurbishment site. The methodology adjusts measured emissions values – CO, NOx, and PN23 – based on driving behavior indicators to mitigate the variability caused by traffic and driving conditions in a procedure called contextualization. Furthermore, a new environmental evaluation score for used vehicles is proposed, based on the Green NCAP rating procedure. The results demonstrate that the proposed contextualization is most effective for vehicles with higher emissions (e.g., older vehicles) and aggressive driving behavior – validating the methodology for the current sample of used vehicles but highlighting the need for future after-treatment system technologies. The observed emission levels in the tested vehicle sample strongly correlate with the evolution of emissions standards, validating the use of REAL-e for such experimental campaigns. Finally, the calculated scores show that 4 vehicles out of the 28 tested received the lowest score, while none achieved the highest score – an expected outcome for used vehicles. Future research will focus on refining the methodology to enhance contextualization and exploring the broader application of REAL-e.
Carlos Da Silva, DanielKermani, JosephFarcot, FabriceGaie, Fabien
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical approach that models the dynamic processes of brake temperature development. The average temperature deviation between the 3D and 1D simulation is less than ΔT1D,3D=1.5 K in the validated section of the WLTP brake. The 1D simulation is coupled with data-based models of brake-induced non-exhaust emissions. This combination enables the generation of detailed, time-resolved emission profiles that account for the variability in driving conditions, such as speed and braking intensity. The methodology further explores and models the key impact factors influencing brake-induced particulate emissions, including material properties, brake system design, and environmental conditions. By providing time-resolved output, the methodology offers a more precise analysis of emission-relevant events in real-world driving scenarios, compared to traditional emission factor approaches, which typically assume constant emission rates. This approach captures the temporal variability of particle emissions during different driving phases. The speed and computational efficiency of the method make it suitable for large-scale simulations, while maintaining high accuracy when validated against experimental data.
Herkenrath, FerrisLückerath, MoritzGünther, MarcoPischinger, Stefan
Low-Cost Mobile Hydrogen Refuelling Stations: A Cost-Effective Solution for India's Sustainable Transportation” The likely depletion of fossil fuel reserves in the next fifty years and growing environmental concerns caused by petroleum fuel-based vehicles highlight the urgent need for sustainable alternatives. India, a developing country, requires a significant amount of energy to sustain its growth, most of which is imported. Hydrogen is one of the cleanest fuels and offers sustainable pathways to a low-carbon future. The government of India has already launched a Green Hydrogen mission and has set up a very ambitious target for 2030. However, the absence of adequate refueling infrastructure is a significant blockade to India's widespread adoption of hydrogen-powered vehicles. The mobile hydrogen refueling station (MHRS) is a flexible system that enables lower initial capital costs than fixed hydrogen refueling stations and allows for the gradual build-up of hydrogen mobility fleets. Such a system could be very useful in India, and it integrates advanced safety features, including hydrogen leak detectors, pressure and temperature sensors, flame detectors, and gas composition analyzers, to ensure the safe dispensing of hydrogen. Such a system can significantly boost local economies by creating employment opportunities at various hydrogen supply chain stages and reducing air pollution. These can dispense hydrogen at both 350 bar and 700 bar pressures, ensuring compliance with international safety standards such as ISO 14687 and ISO/TR 15916. This paper studies the design and economics of a low-cost, scalable Mobile Hydrogen dispensing system. It evaluates its cost-effectiveness, scalability, safety, socio-economic, and environmental impact (using Life Cycle Analysis) in a developing country like India. The results of the study are very promising and suggest that MHRS has a sustainable future in India.
Mathur, AnimeshNayak, AjayKumar, Naveen
Most of the power produced by manufacturing industry in the United States is via combined heat and power (CHP) systems, with most CHP installations using reciprocating internal combustion engines (RICE). RICE CHP systems offer several advantages, such as low installation and operational costs, high performance, load flexibility, and adaptability to various applications spanning from kilowatt to megawatt scales. Noble Thermodynamic Systems' (NTS) core technology, the Argon Power Cycle (APC), is a revolutionary, new power generation system that boosts the efficiency of RICE CHP generation systems while emitting zero greenhouse gasses or producing zero air pollutants, including nitrogen oxides (NOx). The APC uses the noble gas argon, a monatomic gas, which dramatically increases the specific heat ratio of the working fluid, resulting in a significantly higher ideal Otto cycle efficiency. The APC presents a promising solution to reach a carbon-neutral future for the energy needs of pivotal industries such as manufacturing plants. To optimize the efficiency of the APC-RICE, identifying the best engine design is crucial. For very lean operating conditions, using a pre-chamber (PC) can help accelerate the combustion rate and, thus, provide efficient and reliable combustion under diluted mixture conditions. With this motivation, in this work, the actively fueled pre-chamber of a spark-ignited, natural-gas fueled APC-RICE will be optimized to extend high combustion efficiencies to lower load setpoints using lean and diluted mixtures. A level-set-based G-equation model is used to simulate the combustion process in the Reynolds Averaged Navier Stokes (RANS) framework. A validated 3D CFD model is utilized to investigate varying PC design parameters, viz., nozzle number, area, included angle, and PC size. Notable improvements are observed in modified designs when compared to the baseline geometry.
Sharma, EshanKim, JoohanStrickland, TylerScarcelli, RiccardoBeardsell, GuillaumeNilsen, ChristopherSierra Aznar, Miguel
Decarbonizing regional and long-haul freight is challenging due to the limitations of battery-electric commercial vehicles and infrastructure constraints. Hydrogen fuel cell medium- and heavy-duty vehicles (MHDVs) offer a viable alternative, aligning with the decarbonization goals of the Department of Energy and commercial entities. Historically, alternative fuels like compressed natural gas and liquefied propane gas have faced slow adoption due to barriers like infrastructure availability. To avoid similar issues, effective planning and deploying zero-emission hydrogen fueling infrastructure is crucial. This research develops deployment plans for affordable, accessible, and sustainable hydrogen refueling stations, supporting stakeholders in the decarbonized commercial vehicle freight system. It aims to benefit underserved and rural energy-stressed communities by improving air quality, reducing noise pollution, and enhancing energy resiliency. This research also provides a blueprint for replacing diesel in over-the-road Class 8 freight truck applications with hydrogen fueling solutions. The study focuses on the Texas Triangle Megaregion (I-45, I-35, and I-10), the I-10 corridor between San Antonio, TX, and Los Angeles, CA, and the I-5/CA-99 corridors between Los Angeles, CA, and San Francisco, CA. This area represents a significant portion of U.S. heavy-duty freight movement, carrying ~8.5% of the national freight volume. Using the OR-AGENT (Optimal Regional Architecture Generation for Efficient National Transport) modeling framework, the study conducts an advanced assessment of commercial vehicles, road and freight networks, and energy systems. The framework integrates data on freight mobility, traffic, weather, and energy pathways to deliver a region-specific, optimized vehicles powertrain architectures, infrastructure deployment solutions, operational logistics, and energy pathways. By considering all vehicle origin-destination pairs utilizing these corridors and all feasible fueling station location options, the framework's genetic algorithm identifies the minimum number and optimal locations of hydrogen refueling stations, ensuring no vehicle is stranded. It also determines fuel schedules and quantities at each station. A roadmap for station deployment based on multiple adoption trajectories ensures a strategic rollout of hydrogen refueling infrastructure.
Sujan, VivekSun, RuixiaoJatana, GurneeshFan, Junchuan
This study looks into the impact of temperature on the aging of lithium-ion batteries, which are an important component of energy storage systems in electric vehicles. To evaluate battery capacity over time, experiments were carried out at two temperatures, 25°C and 50°C, imitating real-world vehicle circumstances. Pristine cells were initially assessed in terms of capacity and internal resistance. Aging results from cycling indicate that higher operating temperatures, particularly under aggressive conditions (fast charging), lead to accelerated battery degradation due to heat accumulation. Charging at 2C resulted in fast degradation at both temperatures, with the battery reaching its End Of Life (EOL), 80% capacity, in fewer than 200 cycles. Surprisingly, cycling at 50°C resulted in a longer lifespan than 25°C for 1C charge/discharge rates. The 1C charge and 2C discharge regimen at 50°C produced the best results, retaining more than 80% capacity even after 600 cycles. This shows that, given optimal cycling conditions, batteries can last longer, even at high temperatures. Electrochemical impedance measurement demonstrated an increase in ohmic resistance during cycling, notably at 50°C, indicating alterations at the electrode-electrolyte interface. Surface temperature measurements of the cells revealed higher peaks after 2C charging, indicating faster deterioration. This study investigates the effect of aging on lithium-ion batteries under controlled temperature and C-rate settings, focusing on how increased temperatures and rapid charging promote deterioration. The findings offer useful information for optimizing heat management and charging methods, as well as improving battery longevity and performance in real-world electric car applications.
Garcia, AntonioMonsalve-Serrano, JavierEgea, Juan Manuel H.Bekaert, EmilieHerran, AlvaroMarco-Gimeno, Javier
Electric vehicles (EVs) represent a significant stride toward environmental sustainability, offering a multitude of benefits such as the reduction of greenhouse gas emissions and air pollution. Moreover, EVs play a pivotal role in enhancing energy efficiency and mitigating reliance on fossil fuels, which has propelled their global sales to unprecedented heights over the past decade. Therefore, choosing the right electric drive becomes crucially important. The main objective of this article is to compare various conventional and non-conventional electric drives for electric propulsion in terms of electromechanical energy conversion ratio and the thermal response under continuous [at 12 A/mm2 and 6000 rpm] and peak [at 25 A/mm2 and 4000 rpm] operating conditions. The comparative analysis encompasses torque density, power density, torque pulsation, weight, peak and running efficiencies of motor, inverter and traction drive, electromechanical efficiency, and active material cost. This study considered an array of electric traction motor types and their accompanying power converters, including the interior permanent magnet synchronous machine, induction machine, PM-assist synchronous reluctance machine, synchronous reluctance machine, switched reluctance machine, double-stator switched reluctance machine, and double-stator PM synchronous machine. To ensure fairness, all machines share identical outer stator diameters, stack lengths, and current densities. Drive efficiency was assessed using uniform inverters via Ansys Simplorer, while Ansys Fluent was used to conduct consistent thermal analysis to evaluate temperature and cooling effects across all seven machines. Additionally, AVL Cruise M software was utilized to compare the performance of these electric drives under the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC) to simulate the urban, suburban, rural, and highway driving conditions using the Nissan Leaf as the reference electric vehicle.
Patel, Dhruvi DhairyaFahimi, BabakBalsara, Poras T.
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