Pasa, Bruno Roberto, Silveira, Juliano Pereira, Fagundez, Jean Lucca Souza, Lanzanova, Thompson Diórdinis Metzka, Martins, Mario Eduardo Santos, Salau, Nina Paula Gonçalves

Tailpipe NOx Emissions Modeling of a Heavy-Duty Diesel Truck Using Deep Learning Methods

03-18-08-0048

12/11/2025

This study develops deep learning (DL) long–short-term memory (LSTM) models to predict tailpipe nitrogen oxides (NOx) emissions using real-driving on-road data from a heavy-duty Class 8 truck. The dataset comprises over 4 million data points collected across 11,000 km of driving under diverse road, weather, and load conditions. The effects of dataset size, model complexity, and input feature set on model performance are investigated, with the largest training dataset containing around 3.5 million data points and the most complex model consisting of over 0.5 million parameters. Results show that a large and diverse training dataset is essential for achieving accurate prediction of both instantaneous and cumulative NOx emissions. Increasing model complexity only enhances model performance to a certain extent, depending on the size of the training dataset. The best-performing model developed in this study achieves an R2 higher than 0.9 for instantaneous NOx emissions and less than a 2

Shahpouri, Saeid, Jiang, Luo, Koch, Charles Robert, Shahbakhti, Mahdi

Investigation of Active Pre-Chamber Ignition on an Optically Accessible Ultra-Lean DI Hydrogen Engine

2025-01-0524

11/25/2025

Hydrogen is a promising alternative to conventional fuels for decarbonizing the commercial vehicle sector due to its carbon-free nature. This study investigates the ignition and flame propagation characteristics of hydrogen in a 2-liter single-cylinder optical research engine representative of the commercial vehicle sector. The main objective was to enable high power density operation while minimizing NOx emissions. For that, ultra-lean combustion was employed to lower in-cylinder temperatures, addressing the challenge of NOx formation. To counteract delayed and unstable combustion under lean conditions, an active pre-chamber ignition system was implemented. It uses a gas-purged pre-chamber with separate hydrogen injection and spark plug ignition. Turbulent hot gas jets from the pre-chamber ignite the fresh mixture in the main combustion chamber, enabling faster and more stable ignition compared to conventional spark plugs. Additionally, the low volumetric energy density of hydrogen

Borken, Philipp, Bill, Daniel, Link, Lukas, Dinkelacker, Friedrich, Hansen, Hauke

Effect of Fuel Injection Strategies on Performance, Combustion, and Emission Characteristics of Diesel–Diethyl Ether–Fueled Compression Ignition Engine

03-18-07-0043

11/20/2025

This experimental study compared a blend of diesel–DEE (DEE 40% v/v in diesel) with baseline diesel. This experimental study assesses different fuel injection strategies for controlling the in-cylinder charge stratification, such as single, double, and triple injections. The peak in-cylinder pressure under the partially premixed combustion mode was higher than conventional diesel combustion. Higher in-cylinder pressure with increasing dwell time was observed under triple injections. Retarding pilot injections increased the peak in-cylinder pressure. Conventional diesel combustion mode exhibited the highest brake thermal efficiency and lowest emissions with all injection strategies. A longer dwell time of 12° CA showed higher brake thermal efficiency, nitric oxide, and carbon monoxide emissions, whereas hydrocarbon emissions were lower compared to a shorter dwell time of 6° CA. Hydrocarbon and carbon monoxide emissions increased, but nitric oxide and brake thermal efficiency were

Sonawane, Utkarsha, Agarwal, Avinash Kumar

A Comprehensive Study on the Effect of Compression Ratio and Pilot Injection Strategy on Alcohol Compression Ignition

03-18-07-0044

11/13/2025

Achieving compression ignition (CI) with ethanol, a renewable fuel, comes with challenges because of its much lower cetane number compared to diesel. Additionally, ethanol’s high cooling potential and high volatility compared to diesel also offer challenges and opportunities to achieving robust, high-efficiency CI. Increasing the compression ratio (CR) and expanding the injection strategy beyond a conventional close-coupled pilot-main diesel injection strategy can help overcome these challenges. This work experimentally tested ethanol CI with several different injection strategies with CRs ranging from 16.3 to 22.3. The results showed that in homogeneous charge CI (HCCI), increasing the CR improved thermal efficiency but incurred a combustion efficiency penalty. In any CI concept, increasing the CR lowered the required intake temperature to achieve ignition. Using close-coupled pilot injections is an effective way to achieve ethanol CI, but it was also shown that HCCI-like intake

Gainey, Brian, Vedpathak, Kunal, Kumar, Mohit, Lawler, Benjamin

Evaluation of Noise, Vibration, and Harshness–Optimized Cylinder Deactivation on a Class 8 Diesel Truck with Impact on Emissions and Fuel Consumption: A Development of Strategy to Reduce Emissions and Fuel Consumption with Cylinder Deactivation While Providing an Acceptable Cabin Environment

2025-01-5074

11/10/2025

Anticipated NOX emission standards will require that selective catalytic reduction (SCR) systems sustain exhaust temperatures of 200°C or higher for effective conversion performance. Maintaining these temperatures becomes challenging during low-load conditions such as idling, deceleration, and coasting, which lower exhaust heat and must be addressed in both regulatory test cycles and day-to-day operation. Cylinder deactivation (CDA) has proven effective in elevating exhaust temperatures while also reducing fuel consumption. This study investigates a flexible 6-cylinder CDA system capable of operating across any combination of fixed firing modes and dynamic skip-firing patterns, where cylinders transition between activation states nearly cycle-by-cycle. This operational flexibility extends the CDA usable range beyond prior implementations. Data was primarily collected from a test cell engine equipped with the dynamic CDA system, while a matching engine in a 2018 long-haul sleeper cab

Baltrucki, Justin, Matheaus, Andrew Charles, Janak, Robb

Onboard Exhaust Capture and Carbon Sequestration for Off-Highway Vehicles: A Sustainable Approach to Emission Reduction

2025-28-0215

11/06/2025

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

Dual Urea Dosing System with Novel Control Strategy for Enhanced NOx Emission Reduction for High-Power Diesel Generators Application

2025-28-0214

11/06/2025

In the power industry, high-power Diesel Generator (DG) sets often utilize high power V-engine cylinder configurations to enhance power output within a compact design, ensuring smoother operation and reduced vibration. In this V-engine configurations, the exhaust gas mass flow rate is significantly higher compared to inline engines of similar displacement, due to the greater number of cylinders operating in a compact space, which leads to a higher volume of exhaust gases expelled in a shorter duration. This necessitates the use of a dual Exhaust After Treatment System (EATS) to effectively manage NOx emissions. High-power gensets typically emit NOx levels around 9 g/kWh, presenting significant challenges for developers in adhering to stringent emission standards. To address these challenges and meet CPCB IV+ emission norms, we propose a dual urea dosing system integrated with a novel control strategy aimed at optimizing the treatment of exhaust gases. This paper introduces a dual

K, Sabareeswaran, K K, Uthira Ramya Bala, S K, Nejanthen, A, Ravikumar, S, Mahendra Boopathi, YS, Ananthkumar

Development of a Cost-Effective DCU for Diesel Emission Control: Design, Diagnostics, and Compliance

2025-28-0286

11/06/2025

The Dosing Control Unit (DCU) is a vital component of modern emission control systems, particularly in diesel engines employing Selective Catalytic Reduction technology (SCR). Its primary function is to accurately control the injection of urea or Diesel Exhaust Fluid (DEF) into the exhaust stream to reduce nitrogen oxide (NOₓ) emissions. This paper presents the architecture, operation, diagnostic features, and innovation of a newly developed DCU system. The Engine Control Unit, using real-time data from sensors monitoring parameters such as exhaust temperature, NOₓ levels, and engine load, calculates the required DEF dosage. Based on DEF dosing request, the DCU activates the AdBlue pump and air valve to deliver the precise quantity of diesel exhaust fluid needed under varying engine conditions. The proposed system adopts a master-slave configuration, with the ECU as the master and the DCU as the slave. The controller design emphasizes cost-effectiveness and simplified hardware, and

Raju, Manikandan, K, Sabareeswaran, K K, Uthira Ramya Bala, Krishnakumar, Palanichamy, Arumugam, Arunkumar, YS, Ananthkumar

Performance and Emission Characteristics of Diesel Engines Fueled with Watermelon Seed Oil Biodiesel Enhanced with Ferrous Oxide Nanoparticles

2025-28-0218

11/06/2025

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 EGR and Ethanol additive on Performance and Emission Characteristics of Diesel Engine Fuelled with Rubber Seed Biodiesel Blends

2025-28-0224

11/06/2025

Alcohol is being considered as an alternative to traditional fuels for compression ignition engines due to their oxygen content and biomass origin. Although alcohol generally has lower cetane numbers, which makes them more favorable for premixed combustion, they also offer potential for lowering emissions in internal combustion engines, particularly when combined with strategies such as exhaust gas recirculation (EGR). This research focuses on enhancing the performance of a single-cylinder, four- stroke diesel engine by introducing ethanol into the intake port during the intake phase. Diesel and rubber seed biodiesel were used as primary fuels and were directly injected into the combustion chamber. The findings indicated that adding ethanol to rubber seed biodiesel, along with 10% EGR, led to improved brake thermal efficiency and a reduction in NOX emissions. The ethanol injection timing and duration were optimized for effective dual-fuel operation. At full engine load, the highest

Saminathan, Sathiskumar, G, Manikandan, Bungag, Joel Quendangan, T, Karthi

Performance and Emission Characteristics of CI Engines Using Ethanol- Cottonseed Biodiesel Blended with Aluminum Oxide Nanoparticles

2025-28-0210

11/06/2025

As global energy demands continue to grow and environmental challenges intensify, Biodiesel stands out as an environmentally sound and technically feasible alternative to curb fossil fuel use and emissions. This study provides an in-depth analysis of the performance and emissions profile of a compression ignition (CI) engine running on a renewable diesel fuel blend made from ethanol and cottonseed (Cs) combinations enhanced with aluminium oxide (Al2O3) nanoparticles. The experimental fuel blends, consisting of 10%, 20%, and 30% cottonseed biodiesel with 5% ethanol and remaining with conventional diesel, were analyzed under varying engine load conditions. The inclusion of ethanol improved fuel atomization due to its lower viscosity and higher volatility, while Al2O3 nanoparticles acted as advanced combustion catalysts, promoting enhanced oxidation rates and thermal efficiency. Among the blends, B10 (10% cottonseed biodiesel) exhibited superior performance metrics, achieving a brake

T, Karthi, G, Manikandan, Saminathan, Sathiskumar, M E, Chandhuru, S, Bavanya, S, Arunkumar

Impact of Enhanced Physics-Based Estimation Modeling for Trapped Air and EGR in Real-Time Control of Hydrogen Injection in a PFI Internal Combustion Engine

2025-32-0047

11/03/2025

Hydrogen PFI engines face abnormal combustion issues, especially during transient operation. The air-to-fuel ratio and trapped exhaust gas significantly affect combustion stability and NOx emissions, requiring continuous monitoring. Real-time estimation of the trapped gas composition and thermodynamic state is therefore crucial but challenging. This work introduces a real-time, physics-based Multi-Input-Multi-Output (MIMO) model for accurately estimating trapped air and exhaust gas mass at the intake valve closing (IVC) event. In detail, the estimation model makes use of dynamic in-cylinder and exhaust pressure measurements to accurately model mass flows and heat exchange equations with 0.5 CAD resolution. This allows extremely high fidelity when modelling the physical properties of the various chemical species along the engine cycle. Moreover, the model calibration appears only in the form of two coefficients implemented on a lookup table for twelve different operating points

Galli, Claudio, Ferrara, Giovanni, Grilli, Niccolò, Balduzzi, Francesco, Romani, Luca, Vichi, Giovanni

Development of a Combined Injection and Ignition Unit for a Gas Engine with Direct Hydrogen Injection Integrated into the Standard Spark Plug Access Hole

2025-32-0059

11/03/2025

To achieve the desired fuel switch from natural gas to hydrogen in internal combustion engines for combined heat and power units, it is necessary to make some adjustments to the fuel supply system. External gas mixers increase the probability of backfiring when natural gas is replaced by hydrogen. In addition, the low density of hydrogen results in a loss of power. Therefore, direct gas injection is preferred when using hydrogen. A drawback of direct injection is the requirement of higher injection pressures to achieve the desired fuel mass and mixture homogeneity as well as the additional access to the combustion chamber for the direct gas injector in the cylinder head. This paper proposes an alternative approach that does not necessitate the implementation of a high-pressure direct injection system nor additional access to the combustion chamber via the cylinder head. A combined injection and ignition unit, called HydroFit, was developed which uses a sleeve inside the spark plug bore

Rischette, Nic, Holzberger, Sascha, Helms, Sven, Kettner, Maurice

Preliminary Development of a Novel 2-Stroke Petrol Engine for a Hybrid Sport-Tourer Motorcycle

2025-32-0025

11/03/2025

While hybrid electric powertrains are the standard for passenger cars, the application to motorcycles is almost nil. The reason is the increase in weight, cost and overall dimensions, which can compromise the layout and dynamics of the motorcycle. A viable path is to replace the standard internal combustion engine with a much smaller and lighter unit, which leaves room for the installation of the electric components. The 2-Stroke (2S) cycle technology, thanks to double cycle frequency and inherent simplicity, can be the key to reduce engine dimensions, weight and cost, while keeping high power outputs. The HybridTec project, discussed in this paper, aims to develop a compact and lightweight V-90° two-cylinder 2S engine, coupled to an electric motor installed downstream of the gearbox (P3 configuration). The total installed power should be about 110 kW. The engine features loop-scavenging, actuated by a crankshaft-driven supercharger, while an exhaust rotary valve and electronic fuel

Rinaldini, Carlo Alberto, Scrignoli, Francesco, Volza, Antonello, Mattarelli, Enrico, Montanari, Luca, Magnani, Gianluca

Impact of Water Injection on Emission Formation in an HVO-Fuelled NRMM Engine

2025-32-0067

11/03/2025

Water injection in diesel engines is a well-known method of lowering combustion temperatures and thus reducing nitrogen oxide (NOx) emissions. In this study, the influence of water injection in hydrogenated vegetable oil (HVO) operation on NOx formation, particulate emissions and ignition delay is analyzed in comparison to diesel operation on a John Deere JD4045 tractor engine. Both the fuel (HVO) and the water injection system were designed as ‘drop-in’ solutions that enable rapid implementation to reduce emissions, even in existing vehicle fleets. The standard engine control unit of the JD4045 engine was therefore used for the tests. A single water nozzle was installed downstream the charge air cooler to integrate a water injection system. The three operating points of interest were: (1) low speed and high load without exhaust gas recirculation (EGR), (2) high EGR rates at low speed and medium load and (3) the engine's ‘sweet spot’ regarding the emission-tradeoff at high speed and

Fuhrmeister, Jonas, Mayer, Sebastian, Günthner, Michael

Development of the Hydrogen Fueled Internal Combustion Engine for Off-Road Applications

2025-32-0066

11/03/2025

This paper focuses on the potential application of hydrogen fueled internal combustion engine (HICE) in the off-road market, examining HICE based on a diesel engine. In the transition to HICE, priority was given to compatibility with existing systems, minimizing changes from the base engine. By adopting a PFI (Port Fuel Injection) method for fuel injection, low-pressure hydrogen supply was achieved. To address the issue of backfire associated with PFI, optimization of injection pressure using a variable pressure control valve, along with adjustments to valve timing and injection timing, was implemented to suppress backflow of residual gases into the intake system and minimize hydrogen retention. Regarding pre-ignition, in addition to suppressing hotspots, the relationship between the homogenization of the air-fuel mixture and NOx emissions was examined, revealing a correlation. This engine was mounted on a generator, and efforts were made to improve the important characteristic of

Shiraishi, Kentaro, Kishi, Shinji, Kato, Daichi, Mitamura, Kenta, Murakami, Kei, Mikuni, Yusuke

Predicting Transient Soot Emissions in Diesel Engines Using Physical and Machine Learning Models

2025-32-0017

11/03/2025

In recent years, diesel engine emissions regulations have been strengthened worldwide, necessitating the evaluation of regulatory values under transient conditions. Consequently, the need to assess transient states in the development of diesel engines has increased significantly. The evaluation using MBD (Model Based Development) is considered a promising method for achieving both low fuel consumption and simultaneous reduction of NOx and soot emissions. However, the mechanism of soot formation is complex, making it challenging to model mathematically directly. In this paper, hybrid machine learning approaches combining a physical model and a machine learning model are used to validate the prediction of soot emissions under transient conditions in a diesel engine with an EGR system. Various parameters such as fuel consumption and emissions predicted by the physical model are compared with measurements to validate the accuracy of the physical model. The prediction of soot emissions by

Kitamura, Takahiro, Matsuoka, Ayano, Suematsu, Kosuke, Okano, Hiroaki

On Board Monitoring of Water Injection Inducement System and Particulate Filter for 3-Wheeler BS VI OBD II B Diesel Vehicle Norms

2025-32-0086

11/03/2025

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

Development of 2-Cylinder Diesel Engine for European Quadricycles to Achieve EURO 5+ Standard

2025-32-0068

11/03/2025

The EURO 5+ standard (134/2014/EU) has been enforced in the year 2025 for quadricycle in Europe. The exhaust emission regulation under this standard has significantly tightened compared to the EURO4. Also, this standard limits vehicle weight, which remains unchanged from the EURO4 standard. We introduce the unique technologies to meet EURO5+ standard in this paper. Emission limit values of the EURO 5+ standard are more stringent, requiring an 84% reduction in NOx and a 94% reduction in PM compared to the previous standard. Diesel engines with mechanical injection control systems for the previous standard are required significant technological advancements to meet EURO 5+ standard of exhaust emission. The adoption of engine aftertreatment components such as SCR (Selective Catalytic Reduction) for NOx reduction and DPF (Diesel Particulate Filter) for PM reduction are common solution. However, to meet this new regulation, adding the weight of these after-treatment parts would cause the

Nagai, Naotaro, Tennomi, Masanari, Tamura, Akira, Mochizuki, Hiroaki, Kobayashi, Yasushi, Onishi, Takashi

Experimental and Kinetic Study of Methane Blending on The Laminar Combustion and Emission Characteristics of Ammonia Under Various Oxygen Contents at High Temperature and Pressure

2025-32-0060

11/03/2025

As a carbon-free fuel, ammonia is one of the alternatives to traditional fossil fuels, but its combustion characteristics are poor, and it is usually optimized by blending methane and increasing oxygen content. However, there are few relevant studies under different conditions. In this study, the laminar burning velocities (LBV) and flame instability of NH3/CH4/O2/N2 mixture at high initial temperature (T), high initial pressure (p), various oxygen contents (Ω) and methane energy ratios (α) are analyzed using a constant volume combustion chamber (CVCC). Through numerical simulation, how various oxygen contents and methane energy ratios affect the combustion characteristics of NH3/CH4/O2/N2 mixture and NO emission is analyzed. The results show that LBV is positively correlated with T, α and Ω, and negatively correlated with p. Markstein length (Lb) does not change significantly with T, but increases with α and decreases with p and Ω. Both oxygen enrichment and methane blending

YU, Yuantao, Dai, Zhizhuo, Hou, Chunlei, Ye, Mingyuan, Zhang, Xiaolei, Cui, Zechuan, Yin, Shuo, Nishida, Keiya

Experimental Study on Single Cylinder Diesel Engine Port Water Injection and Blends of Biodiesel for Performance & Emission

2025-32-0062

11/03/2025

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

Bhoite, Vikram, Syed, Kaleemuddin, Chaudhari, Sandip, Khairnar, Girish, Jagtap, Pranjal, Reddy, Kameswar

Experimental Study on Hydrogen-Methane Co-Combustion in Small Gas Engines

2025-32-0055

11/03/2025

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

Effects of Intake-Air Heating on a Light-Duty CNG-Diesel Reactivity-Controlled Compression Ignition Engine

2025-32-0003

11/03/2025

Reactivity controlled compression ignition (RCCI) is a promising low-temperature combustion strategy that offers high thermal efficiency with reduced nitrogen oxides (NOx) and soot emissions. However, at low loads, RCCI operation often suffers from incomplete combustion, leading to elevated partial combustion products, such as, unburned total hydrocarbons (THC) and carbon monoxide (CO) emissions. Intake-air heating is a potential strategy to address these issues by enhancing fuel reactivity and promoting more complete combustion. In this study, the effects of intake-air heating (from ambient to ~95°C) on performance, combustion, and emissions were experimentally investigated in a light-duty diesel engine operated in compressed natural gas (CNG)-diesel RCCI mode. Experiments were conducted at low and intermediate loads at various engine speeds. A single injection strategy was employed for low-load, while a double-injection strategy was used at intermediate-load operating condition s. CO

Navaneethakrishnan, P., Sarangi, Asish K, Suman, Abhishek, Sreedhara, Seshadri, Singh, Arvind Kumar

A Physics-Guided Neural Network Approach for EGR Cooler Temperature Estimation: Addressing ECU Model Discrepancies

2025-28-0393

10/30/2025

As the automotive industry explores alternative powertrain options to curb emissions, it is pertinent to refine existing technologies to improve efficiency. The Exhaust Gas Recirculation (EGR) system is one of the pivotal components in emission control strategies for Internal Combustion Engines (ICE). The EGR cooler is crucial in thermal management strategies, as it lowers the temperature of recirculated exhaust gases before feeding it along with fresh air, thereby reducing nitrogen oxides (NOx) emissions. Precise estimation of the EGR cooler outlet temperature is crucial for effective emission control. However, conventional Engine Control Unit (ECU) models fall short, as they often show discrepancies when compared to real-world test data. These models rely on empirical relationships that struggle to capture precisely the transient effect, and real time variation in operating conditions. To address these limitations and improve the accuracy of ECU based model, various signal processing

Kumar, Amit, Kumar, Raman, Manojdharan, Arjungopal, Challa, Krishna, Kramer, Markus

Probabilistic Thermal Modelling of AdBlue System Using Bayesian Networks

2025-28-0370

10/30/2025

In Diesel engine exhaust after treatment system (ATS), Nitrogen Oxides (NOx) emissions control is achieved via Selective Catalytic Reduction (SCR) in which AdBlue or Diesel Exhaust Fluid (DEF) plays vital role. But AdBlue freezes below -11°C due to which in cold climate conditions system performance becomes critical as it affects efficiency as well as overall performance leading to safety and compliance with emission standards issue. So, it is essential to have a probabilistic thermal model which can predict the AdBlue temperature as per ambient temperature conditions. The present paper focuses on developing Bayesian Network (BN) based algorithm for AdBlue system by modelling probability of key factors influencing on its performance including AdBlue temperature, Ambient temperature, Coolant temperature, Coolant flow, Vehicle operating conditions etc. The BN Model predicts and ensures continuous learning and improvement of the system, based on operational data. Methodology proposed in

Thakur, Shivam, Salunke, Omkar

Effect of Flow Speed and Turbulence on Methane Combustion in a Rapid Compression Machine

2025-01-0393

10/07/2025

Recent experimental work from the authors’ laboratory demonstrated that applying a boosted current ignition strategy under intensified flow conditions can significantly reduce combustion duration in a rapid compression machine (RCM). However, that study relied on spark anemometry, which provided only localized flow speed estimates and lacked full spatial resolution of velocity and turbulence near the spark gap. Additionally, the influence of turbulence on combustion behavior and performance across varying flow speeds and excess air ratios using a conventional transistor-controlled ignition (TCI) system was not thoroughly analyzed. In this study, non-reactive CFD simulations were used to estimate local flow and turbulent velocities near the spark gap for piston speeds ranging from 1.2 to 9.7 m/s. Simulated local velocities ranged from 0.7 to 96 m/s and were used to interpret experimentally observed combustion behavior under three excess air ratios (λ = 1.0, 1.4, and 1.6). Combustion was

Haider, Muhammad.Shaheer, Jin, Long, Yu, Xiao, Reader, Graham, Zheng, Ming

IRLAM-An Advanced Technology for NO _x Measurement from Diluted Exhaust of a Light Duty Vehicle (LDV)

2025-01-0403

10/07/2025

The United States Environmental Protection Agency (US-EPA) requires nitrogen oxides (NOx) measurement using Chemiluminescent Detectors (CLDs), Non-dispersive Ultraviolet (NDUV), and Zirconia Oxide (ZrO2) analyzers, as outlined in the 40 CFR Part 1065. Quantification of NO2 by CLD requires dual-CLDs; one dedicated to measuring the NO and another coupled with a NO2-to-NO converter to measure the total NOx. Measurement by using dual-CLDs involves mathematically subtracting NO from total NOx to get NO2 information. This requires perfect time alignments of both CLDs assigned for measuring NO and NOx to maintain accurate NO2 calculations. The NO2-to-NO converters can degrade over time and need to be replaced to get accurate total NOx measurement. In this study, Infra-red Laser Absorption Modulation (IRLAMTM) technology, which is an advanced QCL-IR spectroscopy proposed in the previous study [1], is used to measure NO and NO2 simultaneously in the exhaust gas of light-duty vehicles. This

Rahman, Montajir, Nevius, Tim, Israel, Joshua, Hara, Kenji, Nagura, Naoki

Automated Calibration of Heavy-Duty Low NO _x Aftertreatment System Controls using Deep Learning and Global Optimization Methods

2025-01-0402

10/07/2025

Heavy duty diesel engines provide a robust power plant for transportation applications for both on highway and off road applications. Control of criteria pollutants such as particulate matter and NOx at tailpipe for these applications based on standards set by regulatory bodies such CARB and EPA is critical. SwRI has demonstrated capability to achieve 0.02 g/bhp-hr. tailpipe NOx standard through the application of a model based controls in EPA and CARB funded projects. This control mechanism enables precise urea dosing for both steady state and transient conditions by leveraging estimated ammonia storage state in a dual dosing system using a set of chemical kinetics-based SCR observer models. This controller is highly nonlinear, with a significant amount of controller tuning with up to 55 calibratable parameters. In order to improve the accuracy and reduce the time required for calibration of this controller, this work proposes the deployment of a Deep Learning-based SCR plant model in

Chundru, Venkata Rajesh, Rajakumar Deshpande, Shreshta, Sharp, Christopher, Gankov, Stanislav

Investigation of Transient High Current Ignition for Lean Mixture in Spark Assisted Compression Ignition

2025-01-0390

10/07/2025

Lean burn combustion is an effective strategy to reduce the in-cylinder temperature. Hence reduce NOx emissions and increase the thermal efficiency of the system. One essential aspect of successful combustion is the flame kernel initiation and development. However, as the fuel-air mixture becomes leaner, challenges arise in achieving a stable flame kernel initiation and a moderate speed of flame propagation. This empirical research aims to investigate the impact of the transient high current ignition strategy on flame kernel development, flame propagation and auto-ignition timing of lean Dimethyl Ether (DME). In this work, a rapid compression machine is employed at engine-relevant conditions, a pressure of ~15 bar and temperature of ~650K. Spark-assistance is applied at the end of compression to enable a spark-assisted compression ignition combustion mode. The spark event is initiated by a transient high current ignition system, which includes a traditional transistorized coil ignition

Asma, Sabrina, Yu, Xiao, Jin, Long, Tjong, Jimi, Zheng, Ming

Development of a Self-Adjusting Engine Out NOx Prediction Model Using Tailpipe O2 Measurements

2025-01-0381

10/07/2025

On-Board Diagnostic (OBD) strategies utilize a predictive model to estimate engine out NOx levels for a given set of operating conditions to ensure the accuracy of the Nitrogen Oxides (NOx) sensor. Furthermore, this model is also used to determine urea dosing quantities in situations where the NOx sensor is unavailable such as cold starts or as a reaction to a NOx sensor plausibility failure. Physics-based NOx prediction models guarantee high levels of accuracy in real-time but are computationally expensive and require measurements generally not available on commercial powertrains making them difficult to implement on controllers. Consequently, manufacturers tend to adopt a mathematical approach by estimating NOx under standard operating conditions and use a variety of correction factors to account for any changes that can influence NOx production. Such correction factors tend to be outcomes of base engine calibration settings or outputs of models of other related sub systems and may

Sunder, Abinav, Suresh, Rahul, Polisetty, Srinivas

Reactivity Retention of Modern Converters for Stringent Emission Control

2025-01-0401

10/07/2025

The growing emphasis on environmental protection and sustainability has resulted in increasingly stringent emission regulations for automotive manufacturers, as demonstrated by the upcoming EURO 7 and 2027 EPA standards. Significant advancements in cleaner combustion and effective aftertreatment strategies have been made in recent decades to increase the engine efficiency while abiding by the emission limits. Among the exhaust aftertreatment strategies, three-way catalyst has remained the primary solution for stoichiometric burn engines due to its high conversion efficiency and ability to simultaneously allow both oxidative and reductive reactions in a single stage with spatial separation due to the oxygen storage capabilities of ceria. However, fuel and lubricant-borne sulfur and phosphorus compounds have been shown to have a significant long-term effect on the activity of three-way catalysts, particularly during the lean-rich transitions and oxygen storage processes. In the present

Sandhu, Navjot Singh, Yu, Xiao, Jiang, Chuankai, Ting, David, Zheng, Ming

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