Browse Topic: Carbon dioxide

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Study of Deposit Control Additive Efficacy in Gasoline Direct Injection Engines2026-01-0349To be published on 04/07/2026
There is an increasing adoption of Direct-injection spark-ignition (DISI) engines in the market, which per 2024 EPA Automotive Trends Report represents 73% of new vehicles sold in the US. And while it is well accepted that DISI offers advantages over Port fuel injection (PFI) technology in meeting stringent CO2 emissions and fuel economy requirements set by the EPA, DISI engines are also associated with increased formation of injector deposits. These deposits may foul injectors and accumulate on the injector tip causing distorted spray patterns and diffusive combustion. Ultimately, this leads to engine performance deterioration and increased harmful emissions. To control deposit formation, detergent-type chemistries are added to the fuel in small amounts. Deposit control additives (DCAs) function by preventing the formation of deleterious injector deposits as well as removing existing ones. Standardized protocols describing the assessment of DCA in controlling injector deposits have
Soriano, Nestor, Chahal, Jasprit, Lang, Wendy, Cracknell, Roger, Williams, Rod
PERFORMANCE AND EMISSION ANALYSIS OF CI ENGINES FUELED WITH BIODIESEL BLENDS USING TAGUCHI GREY RELATIONAL ANALYSIS (2026-01-0509To be published on 04/07/2026
Diesel engines are widely used in many areas like automobiles, locomotive marine engines power generations etc., due to its high power output and thermal efficiency. Even though the diesel engines give more benefits, the human discomforts caused by the pollutant emission of these engines have to be considered. The major pollutant emissions of the diesel engines are particulate matters, smoke, CO, CO2, HC, PM and the oxides of nitrogen (NOx). Out of these pollutant emissions, the oxides of nitrogen are considered as the most harmful pollutants to the human health. Taguchi method was used to prepare the design of experiment for optimization of a CI engine for blends of Jatropha biodiesel as a fuel. The results obtained with blends of Jatropha biodiesel were compared with diesel. CI engine input parameters are optimized as follows: 10% fuel fraction, 18 compression ratio, 220 bar injection pressure and 4 hole nozzle geometry with four levels of each parameter by using Taguchi’s L16
Nigade, Shubhangi Sambhaji, Jadhav, Sangram
Model-based Development of a Heavy-Duty H2-ICE and Integrated, Turbogeneration, Electrification, and Supercharging (ITES) System2026-01-0426To be published on 04/07/2026
Changing global economic conditions and efforts to reduce greenhouse gas emissions to reduce their impact on climate and public health is driving the need to develop alternative technologies to meet the demands of heavy-duty vehicles and increase propulsion system efficiency. This study combines a Hydrogen internal combustion engine (H2-ICE) for its near zero CO2 emissions capability, with electrically assisted turbocharging, exhaust energy recovery, and mild hybridization to maximize propulsion system efficiency in real-world driving. The focus is on model-based integration and optimization of a technology package termed as the Integrated, Turbogeneration, Electrification, and Supercharging (ITES) system to demonstrate its potential for low emissions, high efficiency, and reduced cost will be demonstrated. In a previous study, a H2-ICE and aftertreatment concept for a MY2027 7.7L medium heavy-duty on-road engine was developed and evaluated through 1D simulation. The concept was to
Bustamante, Oscar, Correia Garcia, Bruno, Joshi, Satyum, Franke, Michael
A new approach for SI combustion modeling to address the upcoming fuel diversity scenario2026-01-0276To be published on 04/07/2026
Climate change concerns demand a drastic reduction in CO2 emissions, tending to what is called carbon neutrality. Even if political guidelines promote electrification, considering the transportation sector, not all applications have the same requirements and boundary conditions, and hence, their optimal solution is not necessarily the same. In this context, in parallel with pure electric powertrains, the internal combustion engine (ICE) still has a relevant role to play, mainly in hybrid powertrains, working together with an electrical motor. In this hybridization context, the spark-ignition (SI) engine used to be the most adopted solution because of its lower cost and complexity. Consequently, it can be concluded that the SI engine still has a significant role to play in the near future. However, when ICEs are considered, the search for carbon neutrality requires the use of fuels other than fossil fuels. At this point, many alternatives arise, from biofuels to synthetic e-fuels, or
Robayo-Rueda, Daniel, Lopez, J. Javier, Martin, Jaime, Novella, Ricardo
BEV incremental CO2 emissions in a ranked order electric grid2026-01-0424To be published on 04/07/2026
Battery Electric Vehicles (BEV) have been promoted and required by many governments towards the need to reduce transportations CO2 emissions. BEV are not “Zero Emissions Vehicles” because they run on grid electricity, but could be ‘effectively ZEV’ if the incremental CO2 is ‘very small’. To answer this question at the national level, three metrics are needed and estimated: (1) ICEV fuel consumption, approximated by the total US gasoline consumption divided by the total fleet miles driven, 25 mpg or 350 g CO2/mi. For strong HEV it is about one third less, 240 g CO2/mi. (2) BEV energy consumption, using data from systematic on-road testing of a wide range of vehicles, estimated at 40 kWh/100 mi for a US sales mix. (3) Electric grid marginal CO2, with ranked order sourcing: zero-CO2 sources are prioritized and supplemented by fossil sources. IEA hourly data show that the US 48 contiguous states are nearly self-contained, with zero-CO2 sources providing about a third of total demand. The
Phlips, Patrick
Real-Time Observations of the Effect of Fuel Dilution in an Engine Transient Friction Rig. Along with Real-Time Observations of Fuel Entering and Leaving Internal Combustion Engine Oil, over both Standard Engine, ICE and Hybrid, HEV Dynamic Drive Cycles.2026-01-0351To be published on 04/07/2026
Hybrid electric vehicles with an increasing level of electrification, are becoming a major part of the global energy transition. To achieve lower engine tailpipe exhaust emissions and improve total fuel consumption, typically the hybrid electric vehicle (HEV) control system efficiently and frequently switches between the internal combustion engine and electric motor drive, with multiple stops and restarts of the internal combustion engine. A consequential result of this switching is typically slower, or even incomplete engine warm up times, depending on the engine speed, load pattern and run time of the vehicle drive cycle. Along with the speed and load transient control, the engine stop and start processes are also challenging to control, with respect to cold start fuel and combustion by-products entering the oil. Consequently, contamination enters the engine oil but may not completely leave. These effects are highly transient over the drive cycle with contaminants, in particular fuel
Butcher, Richard, Bradley, Nathan, Thedering, Dennis
Effect of Renewable Fuel Blends on Particulate Emissions Under Medium Engine Load and Injector Coking Conditions in a GDI Engine2026-01-0301To be published on 04/07/2026
Renewable gasoline is blended with fossil gasoline as part of the effort to achieve zero net carbon emissions. This study examined how five gasoline fuels with different hydrocarbon compositions affect engine-out gaseous and particle number (PN) emissions. Gasolines F3 and F4 reduce GHG emissions by 54% and 35%, compared with fossil gasoline. The other three gasolines reduce GHG emissions by 4-9%. Tests were conducted on a single-cylinder GDI engine at 10-14 bar indicated mean effective pressure (IMEP) and 2000 rpm. The injector-tip coking behavior of the test fuels and the resulting PN emissions were also investigated at 10 bar IMEP. Spray plume targets and start-of-injection (SOI) timing were adjusted to examine how the test fuels affected PN emissions. An endoscope was used to identify the sources of soot during fuel combustion. The experimental results show that PN varies with gasoline composition and engine operating conditions. Aromatics and olefins contribute more to injector
Muniappan, Krishnamoorthi, Dahlander, Petter, Helmantel, Ayolt, Alemahdi, Nika, Lehto, Kalle
Analysis of In-Cylinder Flow for Hybrid Gasoline Engine using High-Speed Particle Image Velocimetry2026-01-0298To be published on 04/07/2026
To curb global warming, reduction of CO2 emissions in automotive powertrains is required. Hybridization and further improvement of thermal efficiency has been promoted in internal combustion engines. Therefore, the 2.0-liter inline 4-cylinder direct-injection engine for 2 motor-hybrid powertrain have been developed to realize rapid combustion by in-cylinder flow enhancement. In this paper, in-cylinder flow analysis using high-speed PIV on the optical single-cylinder engine was performed, and evaluated the combustion promotion concept by analyzing the bulk flow and the turbulence. To achieve rapid combustion, the intake port shape for tumble flow enhancement and bowl-in type piston which was smoothly converted the tumble flow to upward flow were examined. As a method for turbulent component decomposition, the time filter method proposed by the authors were applied. The characteristics of the time filter method is that turbulent component does not include the cycle-by-cycle fluctuations
Okura, Yasuhiro, Urata, Yasuhiro
The influence of split injection ratio on efficiency and NOx emissions in a pilot diesel-ignited hydrogen direct injection engine2026-01-0329To be published on 04/07/2026
This study investigates the impact of hydrogen split injection ratio on the combustion of pilot diesel-ignited hydrogen direct injection engines, which is expected to affect hydrogen-air mixture conditions and thus flame propagation and diffusion burning. Experiments were conducted on a 1-litre single-cylinder diesel engine equipped with an additional hydrogen injector operating at 35 MPa. Hydrogen of 95% total energy was injected at 150 and 60 °CA bTDC for the first and second pulses, which were selected as high efficiency injection timings from the previous equal split injection tests. The 5% diesel energy was injected near TDC to fix CA50 at 10 °CA aTDC for all tested split injection ratios. While varying the split ratio between the two hydrogen injections, in-cylinder pressure/aHRR profiles, engine efficiency/power output and engine-out emissions of NOx and CO2 were evaluated. Results showed that the hydrogen split ratio does not make a significant impact on IMEP/efficiency, which
Zhao, Yifan, Chan, Qing Nian, Kook, Sanghoon
Achieving Euro 7 WHSC NOx emission targets from a Spark ignited engine using Methanol-Hydrogen co-fuelling.2026-01-0321To be published on 04/07/2026
E-methanol is increasingly seen as a promising clean fuel because its chemical makeup is close to fossil fuels, making it easier to use in existing engines. It offers a carbon-neutral option to help reduce greenhouse gases in sectors where cutting emissions is especially difficult, such as transportation. However, while e-methanol avoids adding new carbon dioxide, burning it in internal combustion engines still releases harmful gases like NOx and other toxic by-products like formaldehyde and formic acid that damage both health and the environment. This report explores a new strategy that combines methanol with hydrogen to run engines under “ultra-lean” conditions and its impact on emissions, performance and efficiency. Experiments were carried out on a single-cylinder spark ignition engine, with directly injected methanol and port fuelled injection of hydrogen. The findings show that adding about 15% hydrogen at low engine loads can extend the lean limit from λ=1.7 to λ=2. This change
Ambalakatte, Ajith, Geng, Sikai, Cairns, Alasdair, Varaei, Amirata, Harrington, Anthony, Hall, Jonathan, Bassett, Mike, Cracknell, Roger
Beyond PFAS: Unlocking the Potential of R290 and R744 for EV Efficiency2026-01-0127To be published on 04/07/2026
The anticipated PFAS ban in the US by 2029 has created a need to evaluate alternative refrigerant solutions for automotive thermal management systems. This work compares three candidates—Propane (R290), Carbon Dioxide (R744), and R1234yf—through system-level testing and demonstration projects. R1234yf remains the current industry baseline. Test results show that Propane (R290) delivers comparable efficiency while offering a significantly lower global warming potential. However, its flammability presents integration challenges, not present with R1234yf or R744. CO₂ (R744) demonstrated promising performance as well. In AVL’s Refrigerant Cooling Project, direct CO₂ cooling battery plate simplified the thermal system architecture and provided adequate cooling capacity during high charging loads. To address safety concerns with Propane, AVL developed mitigation measures including rapid leak detection, robust containment strategies, and optimized circuit layouts designed to reduce ignition
bires, Michael, Possegger, Jonathan
Sensorless Estimation of In-Cabin CO2 Concentration for Model-Based Air Recirculation Control2026-01-0130To be published on 04/07/2026
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
Stürmer, Michael, Geier, Bertram, Hofstetter, Martin, Hirz, Mario
Enhancing combustion, performance and emission profiles using kapok methyl ester blends with hydrogen2026-28-0058To be published on 02/12/2026
This study investigates the potential of using a dual green alternative fuel combination, the one is hydrogen fuel and another one is biodiesel for enhancing the Combustion, performance and emission characteristics of a compression ignition engine. The kapok oil methyl ester was blended with diesel in proportions of 20% (K20) and 40% (K40) by volume. The hydrogen gas was supplied at a constant flow of 4 liter per minute (LPM). The experimental fuels are neat diesel D100, K20 (80% Diesel and 20 % kapok methylester), K40 (60% Diesel + 40 % Kapok methyleter), K20 + H4L (K20 with 4 LPM hydrogen) and K40+H4L (K40 with 4 LPM hydrogen). These blends were tested in a single cylinder direct injection diesel engine under different load conditions at a constant speed of 1500 rpm, combustion, performance and emissions characteristic were evaluated and compared with base fuel. The results indicated that te use of B20 and B40 blends without hydrogen led to reduced brake thermal efficiency due to
Anbarasan, B, M, Kumaresan, Balamurugan, S, Rajesh, Munnusamy
Technologies and Strategies for High Brake Thermal Efficiency Gasoline Engine to Meet the Future CO 2 Emission Targets in India2026-26-007201/16/2026
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
Garg, Shivam, Fischer, Marcus, Emran, Ashraf, Jagodzinski, Bartosch, Franzke, Bjoern
Prediction of REESS Factor for SOC Correction in Hybrid Vehicles2026-26-047101/16/2026
The regulatory mechanisms to measure emissions from automobiles have evolved drastically over the years. Certification of CO2 emissions is one of them. It is not only critical for environmental protection but can also invite heavy fines to OEMs, if not complied with. In homologation test of a Hybrid Vehicle, it is necessary to correct the measured CO2 to account for deviations in measurement from failed Start-Stop phase and difference between start and end State of Charge (SOC) of battery. The correction methodology is also applicable for vehicle simulation in Software-in-Loop environment and for analyzing vehicle test data for CO2 emissions with programmed digital tools. The focus of this paper is on the correction of CO2 derived from SOC delta in the WLTP homologation drive cycle. The battery energy delta due to difference in SOC between start and end of drive cycle should be converted to corresponding CO2 expended from Internal Combustion Engine. The resulting correction factor is
Gopinath, Shravanthi Poorigali, Khatod, Krishna
A Thermoelectric System for Emission Control Optimization in Two-Wheeler Automotive Applications2026-26-021801/16/2026
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
Venkateshwaran, Aishwarya, Soodlu, Shashikiran, M, Mathaiyan
Study of Drive Trace Indices and Their Correlation with CO 2 in Chassis Dynamometer2026-26-051701/16/2026
With introduction of Corporate Average Fuel Efficiency norms (hereafter referred as CAFÉ norms) in India, the manufacturers of all M1 Category vehicles (not exceeding 3,500kg GVW) must ensure that they comply with Annual Corporate average CO2 target as defined in regulation. Moreover, this target will become stricter at various stages in the coming years. Hence CO2 emissions are becoming one of the major focus parameters during vehicle development. There are several factors that can impact CO2 emissions during measurement in laboratory-based test cycles such as MIDC or WLTC. One such major factor is driving variations. Although speed and time tolerances are provided during the test (as part of AIS 137/AIS 175) to limit the variation, even within these tolerances, drive-related effects make significant contribution to test results variability. Monitoring and control of such variations is important to understand the true fuel economy potential of the vehicle. Drive Trace indices are
ER, Shivram, Rawat, Vijaypal, Khandelwal, Vineet, Kumar, Arun, Malhotra, Jitendra
Extreme Learning Machines for Fast Instantaneous Prediction of Emission Level of an Automobile2026-26-022601/16/2026
Addressing climate issues is a key aspect of good global governance today. A key aspect of managing the threats caused to the environment around is to ensure a sustainable transportation system so that humans exist in peace with nature. According to sources, in 2020 alone, cars accounted for approximately 23% of global CO2 emissions. In addition, they also emit dangerous pollutants thus damaging the ecosystem. To keep pollutants in check there are emission level testing strategies in place in each country. However, we can do better for a sustainable future. On one hand, the huge volume of vehicles around the world makes it an excellent choice and source for a vast emission level dataset comprising of input features as well as the target variable representing the emission band of the vehicle. In addition to the big data available as mentioned above, major advancements in the machine learning algorithms are done today. The advent of algorithms such as Artificial Neural Networks (ANN) has
Sridhar, Sriram, Aswani, Shelendra
Evaluating the Environmental Footprint of Electric Vehicles: A Life Cycle Assessment Approach for Sustainable Mobility in India2026-26-023501/16/2026
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
Sonawane, Nayan, Sathaye, Asmita, Gode, Abhishek, Deshpande, Ashish, Shinde, Harshavardhan, Kothe, Anjali
The Aerodynamic Development of a Compact SUV for FE Improvement Compliance with CAFE Norms2026-26-059501/16/2026
The Mahindra XUV 3XO is a compact SUV, the first-generation of which was introduced in 2018. This paper explores some of the challenges entailed in developing the subsequent generation of this successful product, maintaining exterior design cues while at the same time improving its aerodynamic efficiency. A development approach is outlined that made use of both CFD simulation and Coastdown testing at MSPT (Mahindra SUV proving track). Drag coefficient improvement of 40 counts (1 count = 0.001 Cd) can be obtained for the best vehicle exterior configuration by paying particular attention to: AGS development to limit the drag due to cooling airflow into the engine compartment Front wheel deflector optimization Mid underbody cover development (beside the LH & RH side skirting) Wheel Rim optimization In this paper we have analyzed the impact of these design changes on the aerodynamic flow field, Pressure plots and consequently drag development over the vehicle length is highlighted. An
Vihan, Nikhil
3D CFD Combustion Evaluation of Hydrotreated Vegetable Oil (HVO) as a Potential Alternate Fuel for the Future CI Engines2026-26-011301/16/2026
Transportation industry is facing a growing challenge to reduce its carbon footprint and utilize the carbon neutral, more environmentally sustainable fuels to comply with the goal of carbon neutrality. Implementation of carbon free fuels such as Hydrogen, Ammonia and low carbon fuels such as Methanol, Ethanol can significantly reduce the greenhouse gas emissions, but these fuels are suitable for SI engine architecture due to their high-octane ratings. Hydrotreated Vegetable Oil (HVO) is one of the few fuel solutions available today with a high Cetane rating (70-80), that can be used as a drop-in fuel in the existing CI engines, with minimal modifications. The main constituent of HVO is pure alkane and it can be produced from feedstocks such as vegetable oils, animal fats, various wastes and by-products. A closed cycle 3-D CFD combustion simulation using a detailed chemistry-based solver has been conducted with the HVO, on a three cylinder, naturally aspirated water-cooled CI engine at
Tripathi, Ayush, Mukherjee, Nalini, Nene, Devendra
Hybrid Topology Selection & Optimization of a Compact SUV to Meet Future CO 2 Norms – an Indian Case Study2026-26-007701/16/2026
Rising environmental concerns and stringent emissions norms are pushing automakers to adopt more sustainable technologies. There is no single perfect solution for any market and there are solutions ranging from biofuels, green hydrogen to electric vehicles. For Indian market, especially in the passenger car segment, hybrid vehicles are favoured when it comes to manufacturers as well as with consumer because of multiple reasons such as reliability, performance, fuel efficiency and lower long-term cost of ownership. For automakers planning to upgrade their fleets in the context of upcoming CAFE III (91.7 g CO2 / km) & CAFE IV (70 g CO2/km) norms, hybridization emerges as the next natural step for passenger cars. Lately, various state governments have also promoted hybrid vehicle sales by offering certain targeted tax breaks which were previously reserved for EVs exclusively. Current study focuses on various parallel hybrid topologies for an Indian compact SUV, which is the highest
Warkhede, Pawan, Keizer, Ruben, Sandhu, Rouble, Emran, Ashraf
Powertrain Optimization of Indian City Electric Bus Using Active Learning Simulation Methodology2026-26-065701/16/2026
Public transport electrification is going to play a massive role in India’s COP26 pledge to achieve net zero emissions by 2070. India plans to electrify 800,000 buses in a push towards 30% EV penetration by 2030. Further encouraged by government incentives under National Electric Bus Program (NEBP), e-Bus market is expected to grow at a CAGR of ~86% annually over the next 5 years. With most OEMs going for fleet electrification for reducing CO2 emissions and to cater to growing demand in Indian cities for cleaner public transport, improving powertrain efficiency and performance of state-of-the-art e-Buses is a natural progression of e-mobility sector development in India. The first step in designing powertrain for an electric city bus is to determine the motor(s) size and transmission specifications (number of gears, gear ratios etc.). Complications arise due to a wider and non-linear operation range of eBus. This study focuses on powertrain optimization for a medium duty electric city
Sandhu, Rouble, Chen, Bicheng, Emran, Ashraf, Xia, Feihong, Lin, Xiao, Berry, Sushil
Optimizing Hydrogen Engine Performance a Comparative Study of Lean & Stoichiometric Calibration Approach2026-26-026101/16/2026
Hydrogen combustion in internal combustion engines offers numerous advantages, such as zero CO2 emissions and high flame speed, which make it a promising alternative fuel for green vehicle solutions. In order to maximize the engine performance with hydrogen, however, meticulous calibration of the air-fuel mixture must be performed, particularly when lean and stoichiometric combustion conditions are considered. Lean burning, i.e., excess air, offers better thermal efficiency and lower NOx emissions but can cause lower engine power and combustion instability. Stoichiometric combustion, however, ensures complete combustion of the fuel-air mixture, but at the cost of higher combustion temperatures and consequently, high NOx emissions. Calibration strategies for hydrogen engines are presented in this paper by comparing the lean and stoichiometric strategies and their implications on engine power output, efficiency, and emissions. Test data from several hydrogen engine configurations
Jadhav, Ajinkya, Bandyopadhyay, Debjyoti, Sutar, Prasanna S, Sonawane, Shailesh Balkrishna, Rairikar, Sandeep D, Thipse, Sukrut S
Replacing Diesel Engines with CNG Engines – Impact on Emissions, Based on Chassis Dynamometer Tests of Medium and Heavy-Duty Buses2026-26-012701/16/2026
This paper compares carbon dioxide, carbon monoxide, methane, and oxides of nitrogen emissions from medium and heavy-duty buses using diesel, diesel-hybrid, and CNG powertrains. Comparisons are made using results from chassis dynamometer-based tests with driving cycles intended to simulate a wide range of operating conditions. Tail pipe emissions are measured by diluting the vehicle’s exhaust in a full-scale dilution tunnel by mixing with conditioned air. Samples are drawn through probes of raw exhaust, diluted exhaust and measured using laboratory grade emission analyzers. Fuel consumption of diesel is measured using a weighing scale, while a gas flow meter is used for measuring CNG consumption. Experimental data from 19 buses tested on a chassis dynamometer over the last 8 years has been analyzed and a comparison of results from similar buses with the differently fueled powertrains is presented. Based on these test results, it is shown that replacing diesel engines with CNG engines
Iyer, Suresh
Migration from MIDC to WLTP in India: Challenges & Solutions for a Small Commercial Vehicle2026-26-021501/16/2026
In line with global peers (EU, Japan, etc.), the Automotive Industry Standard (AIS) Committee in India has decided to adopt “World harmonized Light vehicle Test Procedure (WLTP)” for M2 and N1 category vehicles not exceeding 3500 kg and for all M1 category vehicles. As a result, “World harmonized Light-duty vehicles Test Cycle (WLTC)” is set to replace currently applicable “Modified Indian Drive Cycle (MIDC)” in the next couple of years. The draft Corporate Average Fuel Economy (CAFE) III & CAFE IV norms for CO2 emission limits, which are set to be implemented in year 2027 and 2032 respectively refer to a shift to WLTP from MIDC. The latest draft of Central Motor Vehicle Rules (CMVR) for BS-VI emissions is also being revised to use WLTC as test cycle. This migration to WLTC is in sync with the demand for test procedures to replicate real driving conditions more appropriately. Further, the move to WLTC along with stricter emission norms is a major step towards realizing India’s COP26
Pawar, Bhushan, Ehrly, Markus, Sandhu, Rouble, Emran, Ashraf, Berry, Sushil
Testing Methodology to Calculate the Fuel Economy in Km/Kg of Hydrogen Fuel Cell Electric Vehicle (FCEV) based on Current (Ampere) Method and Flow Method2026-26-024801/16/2026
The globe is looking headlong to set up new benchmarks for the reduction of GHG (Green House Gases) considering short-term and long-term strategies. Efforts in the Internal Combustion Engines (ICE) domain have been accelerating to find an alternative way to reduce harmful emissions. Hydrogen is considered as a promising fuel to leapfrog this transition. Hydrogen fuel can be categorized into vast mobility areas viz. ICE and Fuel Cell Electric Vehicle (FCEV). Hydrogen fuel has attracted global attention from engine researchers due to the crude oil crisis and its rise in prices in recent years. This will serve the nation's goal towards carbon neutrality. Hydrogen has a few advantages such as less fueling time, higher heating value and more efficiency making it an eye-touching fuel for the automotive industry. In the contemporary FCEV segment, many fuel cell technologies have evolved, wherein the development of Proton Exchange Membrane (PEM) fuel cell technology has taken a new height for
Joshi, Ashish Rajendra, Kandalgaonkar, Siddhesh, Sontakke, Rushikesh
Development of High BMEP Natural Gas Engine with Knock Mitigation2026-26-012101/16/2026
The stringent emission norms over the past few years have driven the need to use low-carbon fuels and after treatment technology. Natural gas is a suitable alternative to diesel heavy-duty engines for power generation and transportation sectors. Stoichiometric combustion offers the advantages of complete combustion and low carbon dioxide emissions. Turbocharging and cooled exhaust gas recirculation (EGR) technology enhances the power density along with reduced exhaust emissions. However, there are several constraints in the operation of natural gas spark ignition engine such as exhaust gas temperature limit of 780 °C, sufficient before turbine pressure for EGR drivability, boost pressure, peak cylinder pressure limit and knocking. These limits coulld restrict the engine BMEP (brake mean effective pressure). In the present study, tests were conducted on a V12, 24 liters, heavy duty natural gas fuelled spark ignition engine (600 HP) with different EGR and turbocharger configurations to
Khaladkar, Omkar, Marwaha, Akshey
Unveiling the Dynamics of Methanol-Diesel Dual Direct Injection Compression Ignition Combustion: A Synergistic Experimental and Numerical Study2026-26-011001/16/2026
The pressing global need for de-fossilization of the transport sector, especially within the heavy-duty segment, has intensified the exploration of alternative clean fuels. In this context, methanol gained traction due to their renewable production pathways, carbon-neutrality, and are being highly promoted by the Indian government to reduce CO2 emissions. Dual direct injection compression ignition (DDICI) is an effective combustion strategy to use methanol in heavy-duty engines, which combines the advantage of high-efficiency compression ignition with the clean-burning potential of methanol. In contrast to spark-ignited premixed methanol engines, this strategy involves a diffusion combustion of the methanol flame, thereby eliminating knocking and enabling running with high compression ratios. This experimental and numerical study presents a comprehensive investigation into the DDICI strategy using methanol as primary fuel and diesel as a pilot for ignition assistance. The work
Singh, Inderpal, Dhongde, Avnish, Raut PhD, Ankit, Güdden, Arne, Emran, Ashraf, Berry, Sushil
Alternative to PFAS Ban: Impact on the Systems and Implementation Challenges2025-36-010212/18/2025
In early of 2023 the European Union began the process of banning the so-called Per- and polyfluoroalkyl substances, with a total elimination forecast for 2035. Currently, the refrigerant gas used by automakers is the R1234yf, a substitute for the R134a as a refrigerant with zero degree of ozone layer destruction, developed to meet the European directive 2006/40/EC that came into force in 2011. It requires all new car platforms for sale on the continent to use a refrigerant in their air-conditioning system with a Global Warming Potential below 150. The alternatives studies for the replacement of R1234yf are R744 (CO2) and R290 (Propane). The first is characterized by being a non-flammable gas and has a working pressure of 6 to 12 times higher than the current one. The second has the characteristic of having working pressure similar to R1234yf, but it is a highly flammable gas. This work focuses on the analysis of the two alternative gases to R1234yf, exploring their characteristics
Ariza, Valquíria Rezende, Erberelli, Diego Pivatto, Silva, Pedro Henrique Moraes da, Miyauchi, Edison Tsutomu
Investigation of the Performance and Emissions of a Compression Ignition Mechanical Engine Operating in a Dual-Fuel Mode with Diesel and CNG2025-36-012712/18/2025
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Oliveira, Lucas, Alvarez, Carlos Eduardo Castilla, Cesar, Felipe
Study of the Performance, Consumption and Range of a Fuel Cell Electric Vehicle Powered by Green Hydrogen2025-36-000712/18/2025
22
Fontana, Romeu
Calculation of Greenhouse Gas Emissions in CO 2 Equivalent per Hectare of Sugarcane Cultivated for Brazilian Ethanol Production2025-36-019112/18/2025
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Assis, Marcelo Suman Silva, Paula Araújo, Gabriel Heleno de, Baeta, José Guilherme Coelho, Abreu, Pedro Blaso Barbosa de, Filho, Fernando Antonio Rodrigues
Research on Optimization Method for Railway Route Schemes in the Western Mountainous Area Considering the “Dual-Carbon” Strategy2025-99-030412/17/2025
Building a green and ecological railway transportation system that incorporates the “Dual-Carbon” Strategy is a central focus and challenge in current industry research. In the western mountainous regions with complex engineering geological conditions and fragile ecosystems, it is particularly important to explore the optimal railway route under the framework of the “Dual-Carbon” strategy. By analyzing the characteristics of the geographic environment of the western mountainous areas and the trend of low-carbon railroad construction, and referring to the relevant principles of railroad line selection, the method of quantifying the carbon emissions during the construction phase of the railroad and the carbon sequestration capacity of the land lost as a result of the railroad project’s land occupation is proposed by selecting 23 indicators from the five aspects of engineering adaptability, low-carbon adaptability, economic adaptability, environmental adaptability, and social adaptability
Wang, Yibo
Multi-Objective Optimization of Oxyfuel Gas Engine Using Stochastic Engine Model and Detailed Chemistry2025-01-052911/25/2025
The energy transition initiatives in Germany’s renown coal mining region Lusatia have driven research into Power-to-X-to-Power technologies, where synthetic fuel is produced from renewably sourced hydrogen and captured CO2, and converted to electricity and heat through oxyfuel combustion. This work investigates the multi-objective optimization of oxyfuel gas engine using a stochastic engine model and detailed chemistry. Exhaust gas recirculation (EGR) rate, initial cylinder temperature and pressure, spark timing, piston bowl radius and depth are selected as design parameters to minimize the exhaust temperature at exhaust valve opening and indicated specific fuel consumption (ISFC) corresponding to oxyfuel operation with different dry and wet EGR rates. The optimization problem is solved for a dry EGR and four wet EGR cases with various CO2/H2O fractions, aiming to achieve comparable performance as in conventional natural gas / air operation, and energy-efficient carbon capture. The
Asgarzade, Rufat, Franken, Tim, Mauss, Fabian
Development of a Comprehensive Predictive QD Knock Simulation Model for Hydrogen, Methanol, and an Ammonia–Hydrogen Blend2025-01-052811/25/2025
To support the transition toward climate-neutral mobility and power generation, internal combustion engines (ICEs) must operate efficiently on renewable, carbon-neutral fuels. Hydrogen, methanol, and ammonia-hydrogen blends are promising candidates due to their favorable production pathways and combustion properties. However, their knock behavior differs significantly from conventional fuels, requiring dedicated simulation tools. This work presents a modeling framework based on quasi-dimensional (QD) engine simulation, including two separate knock prediction models. The first model predicts the knock boundary of a given operating point and combines an auto-ignition model with a knock criterion. The overall methodology was originally developed for gasoline and is here adapted to hydrogen, methanol, and ammonia-hydrogen blends. For this purpose, the relevant fuel properties were incorporated into the auto-ignition model, and a suitable knock criterion was identified that applies to all
Benzinger, Steffen, Yang, Qirui, Grill, Michael, Kulzer, Andre Casal, Plum, Lukas, Hermsen, Philipp, Günther, Marco, Pischinger, Stefan, Hurault, Florian, Foucher, Fabrice, Rousselle, Christine
Optimizing Heavy-Duty Mining Operations with LNG Powertrains: Boosting Efficiency and Minimizing Environmental Impact2025-28-023611/06/2025
Heavy-duty mining is a highly demanding sector within the trucking industry. Mining companies are allocated coal mine sites, and fleet operators are responsible for efficiently extracting ore within the given timeframe. To achieve this, companies deploy dumper trucks that operate in three shifts daily to transport payloads out of the site. Consequently, uptime is crucial, necessitating trucks with exceptionally robust powertrains. The profitability of mining operations hinges on the efficient utilization of these dumper trucks. Fuel consumption in these mines constitutes a significant portion of total expenses. Utilizing LNG as a fuel can help reduce operational fuel costs, thereby enhancing customer profitability. Additionally, employing LNG offers the potential to lower the CO2 footprint of mining operations. This paper outlines the creation of a data-driven duty cycle for mining vehicles and the simulation methodology used to accurately size LNG powertrain components, with a focus
John, Ann Veena, Pendharkar, Koustubh
Onboard Exhaust Capture and Carbon Sequestration for Off-Highway Vehicles: A Sustainable Approach to Emission Reduction2025-28-021511/06/2025
Off-highway vehicles (OHVs) in sectors such as mining, construction, and agriculture contribute significantly to global greenhouse gas (GHG) emissions, particularly carbon dioxide (CO₂) and nitrogen oxides (NOₓ). Despite the growth of alternative fuels and electrification, diesel engines remain dominant due to their superior torque, reliability, and adaptability in harsh environments. This paper introduces a novel onboard exhaust capture and carbon sequestration system tailored for diesel-powered OHVs. The system integrates nano-porous filters, solid-state CO₂ adsorbents, and a modular storage unit to selectively capture CO₂ and NOₓ from exhaust gases in real time. Captured CO₂ is then compressed for onboard storage and potential downstream utilization—such as fuel synthesis, carbonation processes, or industrial sequestration. Key innovations include: A dual-function capture mechanism targeting both CO₂ and NOₓ Lightweight thermal-regenerative adsorption materials Integration with
Vashisht, Shruti
Performance and Emission Characteristics of Diesel Engines Fueled with Watermelon Seed Oil Biodiesel Enhanced with Ferrous Oxide Nanoparticles2025-28-021811/06/2025
A large number of research studies have raised global concerns about the rapid depletion of traditional energy sources like petroleum. These fuels, being largely non-renewable, are being consumed at a rate much faster than they can be replenished. This growing imbalance between demand and supply has led to fears that, in the near future, the world could face a serious energy crisis if alternative sources are not developed and adopted in time. The use of alternative fuels plays an important role in lowering harmful emissions, including those that contribute to ozone formation and other toxic pollutants. It is a well-established scientific understanding that the continued combustion of fossil fuels is a key driver of global atmospheric warming. As environmental awareness grows, many individuals across the globe believe that shifting toward cleaner and more sustainable fuel sources is essential for protecting and improving the health of our planet. Extensive research is being conducted to
G, Manikandan, Subbaiyan, Gunasekharan, Saminathan, Sathiskumar, T, Karthi, S, Gokul, J, Sanmuganathan
Effect of Hydrogen Injection Timing in a Compression Ignition Engine Operating in Hydrogen Diesel Dual Fuel Mode2025-32-005111/03/2025
Stringent European carbon dioxide (CO2) emission regulations have stimulated the development of alternative technologies such as Dual Fuel (DF), which involves partially replacing fossil fuel with a low-carbon alternative. Hydrogen represents an ideal candidate for DF due to its properties, including the absence of carbon, high flame propagation speed, and high diffusivity. This study analyzes the combustion and performance of a 1.0L, naturally aspirated, three-cylinder in-line compression ignition off-road engine with a 17.5:1 compression ratio, originally equipped with a conventional diesel system and modified for diesel-hydrogen dual fuel operation. Three Port Fuel Injectors (PFI) are installed in the intake manifold for hydrogen injection. Additionally, they are strategically positioned to minimize the volume between the intake valve and injector tip. Tests were conducted at a fixed engine speed of 2000 rpm, varying the engine load from 30% to 85% of maximum torque. The diesel
Rossetti, Salvatore, Mancaruso, Ezio
Ca Additive and In-Cylinder Condition on Promotion of Abnormal Combustion in Supercharged SI Engine2025-32-000411/03/2025
Recently, global warming is becoming seriously. In the field of internal combustion engine, the thermal efficiency has to improve in the practical use. One of the current trends with spark ignition engine (SI engine) is “downsizing” which is equipped supercharger with the downsized displacement. The downsizing engine is popular in the field of the SI engine. However, one of the problems is the abnormal combustion so called Low Speed Pre-Ignition (LSPI) [1]. The LSPI occurs the engine operation which is low speed and high load condition. It has to be avoided, because the SI engine is broken and the improvement of thermal efficiency is obstructed. A lot of researchers have been reported about the mechanism of LSPI [2, 3]. One of the sources of LSPI would be the lubricating oil droplets in cylinder. One of the methods to avoid LSPI, it has been adjusted the ingredients of oil additive in lubricating oil. The state of the art of lubricating oil standard has been established anti-LSPI
kitano, Kaito, Tanaka, Junya
On Board Monitoring of Water Injection Inducement System and Particulate Filter for 3-Wheeler BS VI OBD II B Diesel Vehicle Norms2025-32-008611/03/2025
To mitigate greenhouse emissions such as carbon monoxide (CO), carbon dioxides (CO2), oxide of nitrogen (NOx) and particulate matter reduction Government of India implemented Bharat Stage VI (BS-VI) norms from year 2020. Moving to more stringent emission norms poses challenges for automakers in several ways such as meeting exhaust emissions, on board diagnostic, drivers’ inducement, and particulate filter monitoring on vehicle. It is imperative to upgrade engine management system for on-board diagnostics (OBD) that refers to a vehicles self-diagnostic and reporting ability. On board diagnostics systems enables owner of vehicle to gain access of the various vehicle sub-systems. OBD-II standards were made more rigid, requiring the malfunction indicator lamp (MIL) to be activated if emission-related components fail. Also, vehicle emissions carbon monoxide (CO), oxide of nitrogen (NOx) and particulate matter not to exceed OBD thresholds. Consequently, the use of specific oxide of nitrogen
Jagtap, Pranjal, Syed, Kaleemuddin, Chaudhari, Sandip, Khairnar, Girish, Bhoite, Vikram, Reddy, Kameswar
Assessment of Electrification Potential for Hand-Held Powertools and Two-Wheelers2025-32-009411/03/2025
The reduction of the CO2 footprint of transport vehicles is a major challenge to minimize the harmful impact of technology on the environment. Beside passenger cars and light and heavy-duty vehicles, this affects also the two-wheeler category and the non-road mobile machinery (NRMM). One promising path for the de-carbonization is the transition from fossil-fuel powered ICE powertrains to electric powertrains. Several examples of electrified powertrains showcase possibilities for small hand-held power-tools or small mopeds and scooters. As the powertrain categories two-wheeler and NRMM are very diversified and consist of various sub-categories and sub-classes with many different applications, the feasibility of electrification for the whole category cannot be judged by few examples. In this publication, a methodology for assessing the electrification potential of hand-held power tools and two-wheelers is shown. The method uses 4 different factors, which determine the feasibility for
Schmidt, Stephan, Schacht, Hans-Juergen, Weller, Konstantin, Absenger, Johann Friedrich
Clean Cuts, Clear Conscience: Advanced Engines, Optimized Tools, Eco-Friendly Fuels2025-32-008711/03/2025
Handheld outdoor power equipment is utilized globally to shape and maintain the environment, serving as daily assistants in forestry under demanding conditions. In the power tool sector, the transition from petrol to battery-powered products is already well underway, particularly for consumer applications. However, internal combustion engines will continue to be indispensable for professional users of power tools, who place the highest demands on their equipment in terms of performance and energy density. These power tools are often used in remote locations and thus far away from a possible charging infrastructure. To contribute to climate protection, biofuels and RFNBOs are crucial. The continuous optimization of engine technology and its overall system, including cutting tools (such as saw chains and cutting wheels), is a key development goal for STIHL. The optimized interaction between the saw chain, guide bar, and power train is necessary for efficient work progress and ergonomic
Beck, Kai W., Maier, Georg, Müller, Matthias, Lux, Thomas, Kölmel, Armin, Lochmann, Holger, Melder, Jens
Study on CO 2 Absorption via Atomization Utilizing Surface Texturing and Surface Energy for Small Engine Applications2025-32-007611/03/2025
In response to the stringent CO2 regulations set to be enforced in Europe in 2030, there is a global demand for innovative technologies to significantly reduce CO2 emissions from internal combustion engines used in trucks, ships, and other applications. For this reason, future power sources are anticipated to adopt a three-pronged approach: electrification; hydrogen fuel used in fuel cells or internal combustion engines; and synthetic fuels (e-fuels) produced from renewable energy-sourced hydrogen, as approved by the European Commission (EC), and from raw materials that capture CO₂ directly from the atmosphere via the Direct Air Capture (DAC) method, combined with internal combustion engines. In this study, we aimed to absorb and capture “Green” CO₂ emissions from e-fuel and carbon-neutral (CN) fuels combined with internal combustion engines by investigating a method that atomizes a CO₂-absorbing solution. This approach involved spraying the solution and impingement the droplets within
Nohara, Tetsuo, Nara, Shotaro, Kawamoto, Yuki, Fukushima, Naoya, Ochiai, Masayuki
Analysis of Flame Propagation Characteristics in a Hydrogen Engine using an Optically Accessible Engine2025-32-006111/03/2025
This study focused on the effects of hydrogen on the flame propagation characteristics and combustion characteristics of a small spark-ignition engine. The combustion flame in the cylinder was observed using a side-valve engine that allowed optical access. The fundamental characteristics of hydrogen combustion were investigated based on combustion images photographed in the cylinder with a high-speed camera and measured cylinder pressure waveforms. Experiments were conducted under various ignition timings and equivalence ratios and comparisons were made with the characteristics of an existing hydrocarbon liquid fuel. The hydrogen flame was successfully photographed, although it has been regarded as being difficult to visualize, thus enabling calculation of the flame propagation speed. As a result, it was found that the flame propagation speed of hydrogen was much faster than that of the existing hydrocarbon fuel. On the other hand, it was difficult to photograph the hydrogen flame
Arai, Yuto, Ueno, Takamori, Suda, Ryosuke, Sato, Ryoichi, Nakao, Yoshinori, Ninomiya, Yoshinari, Matsushita, Koichiro, Kamio, Tomohiko, Iijima, Akira
Experimental Study on Hydrogen-Methane Co-Combustion in Small Gas Engines2025-32-005511/03/2025
Hydrogen fuel has garnered significant attention as a key method for adapting internal combustion engines to a carbon-neutral society. Hydrogen is a carbon-free fuel that does not produce CO2 emissions during combustion. However, its wide flammability range and extremely low ignition energy present technical challenges when applied to internal combustion engines, such as the frequent occurrence of abnormal combustion phenomena like pre-ignition and knocking. Furthermore, the low energy density of hydrogen makes it difficult to achieve high power output. Additionally, hydrogen’s high adiabatic flame temperature and short quenching distance result in increased NOx emissions and cooling loss, which are further obstacles to its use. To address these issues, this study focuses on methane blending as a remedial approach. Experiments were conducted using a naturally aspirated engine with a premixed intake method to investigate the effects of methane-hydrogen blending. The following key
Tanaka, Kenta, Tani, Toshihiro, Sako, Takahiro
Higher-Strength, Higher-Toughness Die Cast Wheel Material using Recycled Aluminum2025-32-000711/03/2025
In an attempt to reduce CO2 release from alloy wheel production, we have developed an aluminum alloy for casting that satisfies necessary property requirements using recycled aluminum, but without heat treatment. The wheel is a critical safety feature of any vehicle, and it should have toughness and strength .In many wheels, virgin aluminum containing small amounts of impurities is used to maintain toughness, and heat treatment (T6), which is post-casting quick heating and quenching, is applied to provide strength. At the start of this project, we focused on two wheel-manufacturing processes, production of virgin aluminum and heat treatment, from which a large amount of CO2 is released. By switching to recycled aluminum, CO2 was reduced to one-ninth the original amount. The issue with recycled material is that impurities grow in the metal structures as intermetallic compounds and this reduces toughness. To deal with this issue, we have chosen high-pressure die casting (HPDC), in which
Suzuki, Noritaka
Research and Calculation Method of Road Maintenance Carbon Emission in Expressway Operation Period2025-99-006710/17/2025
In recent years, the greenhouse effect has become a major challenge for sustainable development, with carbon dioxide emissions playing a significant role. In 2022, China’s carbon dioxide emissions reached 12,667,430 tons [1], the highest globally, with the transportation sector contributing about 8% of this, and road transportation accounting for 90% of the sector’s emissions. To promote green development, the Chinese government emphasizes efficient resource use, energy conservation, and emissions reduction, aiming to build a strong transport system by 2035. Understanding carbon emissions in expressway construction is crucial for green development. Studies on highway carbon emissions focus on emissions from road construction and vehicle operation. For example, Chen et al. used a “bottom-up” method to account for emissions during construction, while Tu et al. created a vehicle carbon emission model during operation. With the expanding highway network, maintenance has become essential
You, Shuting, Xu, Ziheng, Gao, Yihan, Zhang, Zhishuo, Li, Zihao
The Analysis of Community Entrance Openness on Transportation and Emission: A Comparison of Different Automobiles2025-99-008110/17/2025
With the escalating rate of urbanization in China, the urban construction sector is encountering numerous challenges, including issues such as traffic congestion and environmental pollution. To enhance traffic efficiency and offer planning guidance for urban development, this study focuses on the fully or partial opening of community entrances. VISSIM is utilized to examine the community opening and simulate the internal road network, while also employing the SPSS data analysis tool for supplementary analysis. The objective of this method is to compare and analyze the traffic conditions and environmental impact of the community before and after its opening with different automobiles. Through the establishment of a comprehensive evaluation system, the study calculates and analyzes the average vehicle speed, noise levels, energy consumption, and carbon dioxide emissions before and after the opening of the community. Finally, several recommendations are proposed to enhance community
Li, Mengyuan, Zhuo, Chenxu, Xiong, Simin, Xu, Lihao
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