Browse Topic: Emissions

Items (24,333)

Experimental and kinetic Modeling Study of Aged Three-way Catalyst Performance

2026-01-0373To be published on 04/07/2026

A comprehensive global kinetic model has been developed for an aged commercial Three-Way Catalyst (TWC), incorporating key reaction pathways including oxidation of CO, CH₄, C₂H₆, and H₂; reforming of CH₄ and C₂H₆; the water-gas shift reaction; and NO reduction via CO and H₂. The model also accounts for oxygen storage capacity (OSC) and its dynamic interaction with CO and H₂. To calibrate kinetic parameters, systematic bench-scale flow reactor experiments were conducted under lean, stoichiometric, and rich conditions. Performance metrics focused on CH₄ and C₂H₆ oxidation and reforming across varying O₂ and CO concentrations, and NO reduction with CO and H₂ under different oxygen levels. Experimental results revealed CO inhibition effects on CH₄ and C₂H₆ reforming. NO conversion was observed between 150°C and 600°C, with H₂-driven reduction producing NH₃, N₂, and N₂O depending on lambda (λ). Under rich conditions, complete NO conversion occurred from 150°C, while lean conditions showed

Raj, Richa, Kim, Mi-Young, AIGBIREMOLEN, Grace, Srinivasan, Anand

Achieving 70% Urban Fuel Consumption Reduction: An Opposed-Piston Engine-Based Mild-Hybrid Powertrain Architecture for Light Commercial Vehicles (JLA-2/JLA-T)

2026-01-0432To be published on 04/07/2026

This paper proposes a novel powertrain architecture for the urban Light Commercial Vehicle (LCV) segment, leveraging the compact JLA-2 opposed-piston (OP) engine paired with the reconfigurable JLA-T mild-hybrid architecture. Within SAE literature, OP engines are consistently associated with simplicity. As highlighted by Tom Ryan III (2008 SAE President) in the foreword of Opposed Piston Engines: Evolution, Use, and Future Applications, this architecture is characterized by its manufacturing simplicity” and described as a “relatively simple, robust, and cost effective” power unit solution. The present work builds on this established view. The JLA-2 engine solves traditional packaging constraints by reducing the block width by 30% for horizontal installation and is volumetrically self-sufficient, eliminating external compressors. Although the gear train required for crank synchronization introduces design challenges, explicitly accounted for in our model, the elimination of the cylinder

Nigro, Norberto, Aguerre, Horacio, Carignano, Mauro Guido, Alonso, José Luis, Juni, Carlos A.

Simultaneously NOx and Fuel Reduction for Off-Road

2026-01-0296To be published on 04/07/2026

Simultaneously reducing criteria pollutants and fuel consumption is important for clean air and improving vehicle total cost of ownership. The goal of this effort was focused on a 90% NOx reduction and 10% fuel savings for an off-road 407 kW diesel engine. The baseline was a current production Fiat Powertrain 13L engine and aftertreatment system meeting 0.4 g/kW-hr NOx. The baseline system was quantified over the NRTC, RMC, new low load cycle and five field cycles. A next generation engine was built incorporating many fuel-efficient approaches such as higher compression and reduced parasitic loads. Cylinder deactivation and EGR pump technologies were added to this engine as well. The combination was optimized prior to adding advanced aftertreatment systems, showing the trade-off of engine out NOx and exhaust temperature. Two next-generation catalyst technologies were employed into a LO-SCR plus main SCR system, both with and without an electric heater upstream of the LO-SCR. These

McCarthy, James, Wine, Jonathan, Bradley, Ryan, Hasseman, Andy, Prikhodko, Vitaly, Howell, Thomas

Sensor Fusion Method for In-Cabin Humidity Prediction

2026-01-0131To be published on 04/07/2026

Maintaining optimal in-cabin humidity levels is part of occupant comfort, air quality, and the effective operation of climate control systems, particularly for functions like windshield defogging. This paper introduces a novel sensor fusion methodology for predicting in-cabin humidity without the need for a dedicated humidity sensor. The proposed approach leverages readily available vehicle data, integrating information from ambient temperature sensors, in-cabin temperature sensors, occupant detection systems, window status (open/closed), and climate control settings. By intelligently fusing these diverse data streams, a predictive model is developed to infer the dynamic humidity conditions within the vehicle cabin. We discuss the complex interactions between these parameters, such as the moisture contribution from occupants, the influence of external air ingress through open windows, and the dehumidifying or humidifying effects of the HVAC system. The paper details the development and

Ghannam, Mahmoud, Schroeter, Robert, Shaik, Faizan

Enhancing LiDAR Performance under Fog with Adaptive Multi-Echo and Feature-Based Filtering

2026-01-0011To be published on 04/07/2026

LiDAR (Light Detection and Ranging) systems are essential for autonomous driving (AD) and advanced driver-assistance systems (ADAS), providing accurate 3D perception of the surrounding environment. However, their performance significantly deteriorates under adverse weather conditions such as fog, where laser pulses are scattered by airborne particles, resulting in substantial noise and reduced ranging accuracy. This scattering effect makes it difficult to detect objects within or behind particulate matter, posing a serious challenge for reliable perception in real-world driving scenarios. To address this issue, we propose an algorithm that combines adaptive multi-echo signal processing with a feature-integrated, rule-based denoising framework to enhance LiDAR performance in noisy environments. The multi-echo approach selectively utilizes meaningful signal returns by evaluating both reflection intensity and relative echo positions. Based on predefined rules, the algorithm identifies the

Kaito, Seiya, Zheng, Shengchao, Fujioka, Ibuki, Beppu, Taro

Beyond PFAS: Unlocking the Potential of R290 and R744 for EV Efficiency

2026-01-0127To 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

The influence of split injection ratio on efficiency and NOx emissions in a pilot diesel-ignited hydrogen direct injection engine

2026-01-0329To 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

Virtual Sensor Development for Real-Time Estimation of Transient NOx Emissions for Internal Combustion Engine

2026-01-0370To be published on 04/07/2026

Accurately measuring NOx emissions under transient engine conditions is becoming increasingly important with upcoming Euro 7 and EPA 2027 regulations. Traditional physical sensors often struggle with cost and response time, especially with aging of sensors in dynamic operation. This paper introduces a machine-learning–based virtual NOx sensor that can provide real-time emission estimates while reducing reliance on hardware sensors. The approach uses multiple machine-learning methods (Random Forest, Bootstrap Aggregating, Adaptive Boosting, Gradient Boosting, Extreme Gradient Boosting) and selected best one to establish correlations between engine operating parameters, measured steady-state data, and transient duty cycle NOx emissions. Validation across different duty cycles has shown strong alignment with physical sensor readings, with R² values above 0.9995 for known data sets and above 0.9534 for unseen conditions. The model needs to be trained with larger training samples to further

Kumar, Chandan, Dahodwala, Mufaddel, Thawrani, Kiran

Enhanced Catalyst Heating Control Strategy within Hybrid Electric Powertrain Architectures

2026-01-0414To be published on 04/07/2026

Kudupley, Harshal, Pooyafar, Payam, Karogal, Indrasen, Patel, Nadirsh

Effects of Gasoline Composition and Operating Parameters on the Response of Knock Limit to Nitric Oxide in a Lean-Burn DI-SI Engine

2026-01-0313To be published on 04/07/2026

Lean operation of spark-ignition engines can lead to efficiency gains and lower NOx emissions due to reduced combustion temperatures. However, lean operation may still encounter difficulties with end-gas autoignition and knock, which worsen by the presence of trapped NO in the cylinder. This study assesses the impact of intake-seeded NO on end-gas autoignition and knock for two gasolines with similar octane rating but different composition: high cycloalkane fuel (HCA) and high olefin fuel (HO). Experiments were performed at stoichiometric and lean (lambda = 2) conditions and at two engine speeds of 1400 rpm and 2000 rpm to investigate the influence of equivalence ratio and residence time on end-gas autoignition trends. Chemical kinetics simulations revealed that the mechanisms that control the effect of NO on knock are similar at lambda = 2 and lambda = 1, with NO + HO2 = NO2 + OH being the main pathway for enhancing reactivity by promoting low-temperature heat release (LTHR

Kim, Namho, Abboud, Rami, Sjöberg, Magnus, Lopez Pintor, Dario, Saggese, Chiara, Matsubara, Naoyoshi, Kitano, Koji, Yamada, Ryota, Sugata, Kenji

Peak SCR Efficiency for Ultra-Low NOx Using Electrically Heated Mixer for EU-VII and China-VII

2026-01-0363To be published on 04/07/2026

Achieving ultra-low NOx emissions remains a major challenge in diesel emission control worldwide, especially as increasingly stringent regulations are introduced globally. Selective Catalytic Reduction (SCR), the leading NOx reduction technology in diesel systems, performs best when both heat and ammonia are available. At the same time, any proposed solution must also be cost-effective and economically viable. In this work, we present a low-cost Electrically Heated Mixer (EHM). EHM not only significantly reduces urea deposit formation, thereby lowering warranty costs and mitigating failure modes, but also enhances SCR efficiency, especially in challenging low-load conditions having low exhaust temperature. EHM is also ideal for rapid heat-up and urea injection during engine cold-start conditions ( <100 °C) enabling swift NH₃ formation and storage in the SCR catalyst. Additionally, it enables early urea injection (~ 130 - 150 °C), improving SCR efficiency in low temperatures below 200

Masoudi, Mansour, Poliakov, Nick

Effect of Renewable Fuel Blends on Particulate Emissions Under Medium Engine Load and Injector Coking Conditions in a GDI Engine

2026-01-0301To 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

Advancing Oil Consumption Prediction with 3-D Multiphase CFD: Insights into Piston Design Impacts

2026-01-0282To be published on 04/07/2026

Engine oil consumption contributes to hydrocarbon and particulate emissions, catalyst degradation, and reduced thermal efficiency. Reducing it is essential for meeting emission standards and improving engine reliability. This study introduces a 3-D Computational Fluid Dynamics (CFD) framework that captures micron-scale gaps in the piston-ring-cylinder system while accounting for ring dynamics. The model leverages Simerics-MP+ features—including a novel mesh motion strategy and Mismatched Grid Interface (MGI) coupling—to resolve fine crevice regions alongside coarser bulk domains. It incorporates piston translation, ring motion, and crankshaft rotation, and uses the Volume of Fluid (VOF) method to capture multiphase interactions in thin oil films. Compared to experiments, this approach offers detailed flow visualization in optically inaccessible regions at lower cost and complexity. Unlike traditional 1-D models, it captures nonlinear behaviors without relying heavily on parameter

Mohapatra, Chinmoy K., Schlautman, Jeff, Manne, Venkata Harish Babu, schroeder, Debera, Srinivasan, Chiranth

BEV incremental CO2 emissions in a ranked order electric grid

2026-01-0424To 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

Improving Transient Diesel Performance with E-Supercharging and Multiple-Input Multiple-Output Controls

2026-01-0444To be published on 04/07/2026

Engine torque response for turbocharged diesel engines is limited by lag in air supply to the engine restricting the rate at which fuel can be delivered. This delay can lead to rich air-fuel mixtures and elevated soot emissions during transient events. Electric forced induction systems (EFIS) offer a potential solution to address both of these challenges. For this study, an electric supercharger (E-Booster) is integrated with the original forced induction system of a 4.5-L 4-cylinder turbocharged diesel engine to create a two-stage boosting system that assists induction during transients. Electric supercharger operation is managed by two control schemes, a model-based single-input single-output (SISO) and a model-based robust multiple-input multiple-output (MIMO) controller. Constant speed load acceptance (CSLA) experiments and emulated drive-cycles were performed in a dyno cell evaluating both control methods. The E-supercharged two-stage boosted engine has demonstrated significant

Vang, Nicholas, Rothamer, David, Ghandhi, Jaal, Ashta, Shubham, Qiu, Weijin, Rayasam, Sree Harsha, Shaver, Greg, Frushour, Bryan, Dou, Danan

On-Road Vehicle Testing and Characterization

2026-01-0195To be published on 04/07/2026

Vehicle testing for fuel economy and emissions is typically performed indoors over standard dynamometer drive schedules to minimize variability and maximize repeatability of the results. In contrast, during on-road operation, operational parameters such as vehicle speed and acceleration and environmental factors such as temperature and wind will change unpredictably. These factors influence vehicle fuel economy and emissions, making on-road operation much more variable than dynamometer results. However, even though on-road conditions may be unpredictable, the on-road operational data can still be used to characterize vehicle performance. This paper describes the development of an on-road vehicle test methodology, with a focus on accounting for on-road factors with a high degree of accuracy while requiring only an achievable and reasonable amount of data. To develop this methodology, a 2016 Honda Civic was instrumented and driven multiple times over a route covering urban, rural, and

Moskalik, Andrew, Barba, Daniel

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 Exhaust Gas Components on Oxygen Storage Capacity Measurements of Automotive Catalysts

2026-01-0360To be published on 04/07/2026

Three-way catalytic converters (TWC) are one of the most popular methods to help reduce harmful tailpipe emissions emitted from internal combustion (IC) vehicles. To help improve conversion efficiency, TWCs can store and release oxygen via an oxygen storage capacity (OSC) mechanism. During engine control unit (ECU) calibration, on board OSC measurements are correlated to TWC and vehicle emissions to monitor emissions performance throughout the full useful life (FUL) of the vehicle. It is known that different test conditions, including temperature, space velocity and background gases in the exhaust stream affect OSC measurement, potentially altering the calculated OSC values and thus the perceived level of OSC and emissions preformance during operation. This study utilises an OMEGA test bench to complete OSC measurements on the full-scale automotive catalyst samples to quantify the effects of different background gases including carbon monoxide, hydrocarbons and nitric oxide on OSC

Mc Grane, Liam, Douglas, Roy, Irwin, Kurtis, Woods, Andrew, Elliott, Matthew, Istrate PhD, Oana, Nockemann, Peter

Effect of passive pre-chamber geometry on performance and emissions of a single-cylinder natural gas large bore engine.

2026-01-0333To be published on 04/07/2026

The maritime industry is one of the most energy-intensive sectors, characterized by high fuel consumption and significant environmental impact. As global trade mainly relies on shipping, the challenge of reducing pollutant and greenhouse gas emissions becomes ever more pressing. Natural gas (NG) is regarded as a transitional fuel, capable of lowering CO₂ emissions by 20–30% compared to conventional marine fuels. However, to fully harness this potential, significant advances in combustion technology are necessary, particularly when ultra-lean combustion strategy is adopted. One of the most promising pathways is pre-chamber combustion, a solution that can simultaneously improve the efficiency and sustainability of NG marine engines. In this scenario, the passive pre-chamber geometry plays an important role, as it directly influences ignition behavior, combustion stability and exhaust emissions. This work presents an experimental study carried out on a single-cylinder marine engine

Marchitto, Luca, Tornatore, Cinzia, Pennino, Vincenzo, Mariani PhD, Antonio, Beatrice, Carlo, Accurso, Francesco, Gorietti, Valentina, Pesce, Francesco, Giardino, Angelo, Vitti, Luciano

Effect of Ignition Energy on Combustion Duration under Flow Conditions

2026-01-0336To be published on 04/07/2026

Utilizing low carbon fuel in lean burn combustion presents a compelling strategy for improving thermal efficiency and reducing NOx emissions. Methane, the main content of natural gas, still receives challenge of a rapid and complete combustion process because of its low chemical reactivity. Further increase of excess air ratio would decrease the flame propagation speed significantly, leading to prolonged combustion durations. The long combustion duration deteriorates the performance of a spark ignition engine, in terms of poor combustion instability and misfire. Although ignition timing can be utilized to adjust the combustion phasing, the ignition process faces challenges due to reduced background pressure and temperature at advanced spark timings. In this paper, a rapid compression machine equipped with a specially designed combustion flow chamber is utilized to enhance the mean flow speed across the spark gap under the background pressure 6 bar abs. and temperature 600 K. A

Jin, Long, Yu, Xiao, Reader, Graham, Zheng, Ming

Assessing Energy Use, Cost, and Emissions of Small Regional Rail Vehicles: Methodology and Case Study on a German Track

2026-01-0419To be published on 04/07/2026

The decarbonization of regional rail remains a pressing challenge in the European Union, where nearly half of the 200,000 km network remains unelectrified. Lightweight, single-car railbuses historically provided efficient service on such lines, but modern replacements are scarce. This work evaluates a standardized 30-ton, 16 m railbus platform for unelectrified regional service, focusing on propulsion system design and trade-offs between range, cost, and emissions. A MATLAB/Simulink drive-cycle model was developed to simulate energy consumption under realistic operating conditions. The Erfurt–Rennsteig route in Germany (130 km round trip, gradients up to 6 %) was selected as a representative case study. The model incorporates sub-models for traction motors, lithium-ion batteries (LFP and LTO), fuel storage, fuel cells, and ICE gensets across multiple fuel options (diesel, gasoline, methane, ethanol, methanol, HVO, FAME, and hydrogen). Battery lifetime is estimated using a combined

Ahrling, Christoffer, Tuner, Martin, Gainey, Brian, Torkiharchegani, Amir, Scharmach, Marcel, Hertel, Benedikt, ALAKÜLA, Mats

Development of a zeolite-based (HC Trap type) cold-start catalyst (CSC) for meeting Tier4/LEV IV tailpipe emission standards, Part IV

2026-01-0364To be published on 04/07/2026

This is a follow-up paper to the three previous reports [1, 2&3] regarding the development of a zeolite-based hydrocarbon (HC/NOx) trap-type of cold-start catalyst (CSC) as a cost-effective approach to meet future more stringent vehicle tailpipe emission standards, such as Tier 4/LEV IV. One of the main challenges of meeting Tier 4/LEV IV tailpipe emission standards is both SC03 and US06 test cycles start at room temperature (cold) in steady of at elevated temperature (hot) in Tier 3/LEV III. In this paper, a hybrid vehicle with a Tier3 Bin30 and a Tier3 Bin20 certified aftertreatment systems were tested in cold SC03 and cold US06 cycles. It requires about 64% and 52% tailpipe emissions reduction, respectively, in cold SC03 for the HEV with these two aftertreatment systems to meet Tier 4/LEV IV Bin30 tailpipe emission engineering target of (NOx+NMHC) 13.13 mg/mile. In cold US06 tests, it requires to decrease 50% and 38% of tailpipe emissions, respectively, for the HEV with these two

Xu, Lifeng

Experimental Research on Rapid Test Method for NOX and PN Emissions of Heavy Duty Vehicles

2026-01-0375To be published on 04/07/2026

This article investigates the rapid testing equipment for NOX and PN, starting from the testing principle, discusses the development history of rapid testing for NOX and PN at home and abroad, and introduces the relevant equipment currently used for NOX and PN emission testing. By running the PEMS verification test conditions specified in Annex DC of GB 18352.6-2016 on a light-duty vehicle chassis dynamometer, and collecting emission data from portable emission devices, rapid PN testing devices, and CVS emission analyzers, the correlation and deviation between portable emission devices, rapid PN testing devices, and CVS emission analyzers are analyzed; By simulating vehicle idle and C-WTVC operating conditions on a heavy-duty vehicle chassis dynamometer, analyze the correlation between emission data at idle and C-WTVC operating conditions when the accelerator pedal is fully depressed; By running the WHTC and WHSC cycles specified in GB 17691-2018 on the engine bench, and collecting

Li, Lan, Ni, Jiacheng, Liu, Yiming, Zhuo, Yuanhong, Bai, Qi, Fu, Chunyun, Kang, Zhe

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

Enhancing Understanding of State-of-the-Art Fe/zeolite Selective Catalytic Reduction Catalysts

2026-01-0362To be published on 04/07/2026

Fe/zeolite selective catalytic reduction (SCR) catalysts are commercially used for NOx emissions reduction from diesel engines. In comparison to Cu/zeolite, these catalysts are widely reported to form less N2O as a byproduct of the SCR reactions between NOx and NH3, and Fe/zeolite SCR catalysts also achieve impressive deNOx at high temperatures. On the other hand, Fe/zeolite SCR is much less active than Cu/zeolite for low temperature NOx conversion under standard SCR conditions (NO+NH3). In this study, a state-of-the-art Fe/zeolite SCR catalyst is probed with a combination of BET surface area analysis, SEM/EDX physicochemical characterization, reactor-based performance and active site quantification, and in-situ DRIFTS. The results are split into 3 sections evaluating the impacts of: degreening, mild hydrothermal aging, and extreme hydrothermal aging. In a degreened condition, the impact of water vapor on standard and fast SCR is assessed, and the isothermal desorption of NH3 is

Ottinger, Nathan, Xi, Yuanzhou, Liu, Z. Gerald

Impact of Hydrogen on Methane and Pollutant Emissions over Three-Way Catalysts with Natural Gas–Hydrogen Blends

2026-01-0357To be published on 04/07/2026

Natural gas (NG) is a domestically abundant, low-cost fuel with the potential to displace gasoline and diesel fuel in commercial and off-road vehicles. NG engines typically produce lower engine-out pollutant emissions, such as NOx, CO and particulate matter, which could simplify emission control systems. Blending NG with hydrogen (H₂) can improve engine performance and increase combustion efficiency to further reduce engine-out emissions. Additionally, the presence of H2 in the exhaust stream may also facilitate the catalytic conversion of methane and other pollutants, resulting in cleaner tailpipe emissions. This study evaluates the impact of H2 on the conversion of methane, CO, and NOx emissions on a commercial three-way catalyst (TWC) in a flow reactor using synthetic gas mixtures that simulate stoichiometric engine exhausts with NG or NG+H₂ combustion. The work examines whether, and how, the additional amount of H₂ in the exhaust stream affects the conversion efficiency of methane

Prikhodko, Vitaly, Wang, Min, Park, Yeonshil, Chen, Hai-Ying, Pihl, Josh

Experimental Evaluation of After-treatment Solutions for Heavy-Duty Natural Gas Vehicles to meet future CNVII Regulations

2026-01-0376To be published on 04/07/2026

The heavy-duty truck market in China has seen a significant increase in the adoption of natural gas-powered engines over the past two years. Simultaneously, the anticipated release of the China VII emissions regulation proposal by the end of 2025 is expected to impose stricter emissions limits on all heavy-duty engines, including new particulate number (PN10) thresholds analogous to those in the Euro 7 regulation. While tailpipe NOx and methane (CH4) emissions from natural gas engines can be mitigated through tighter lambda control and adjustments to catalyst volume and precious metal (PGM) loading, addressing particulate number (PN) emissions necessitate more advanced after-treatment solutions. Although natural gas combustion is virtually soot-free, the entrainment of lubricating oil into the combustion chamber, especially during cold-start conditions, poses a challenge, leading to potential exceedance of the proposed future China VII limits. Additionally, PN emissions from natural

Jiahui, Gao, Marc C, Besch, Ding, Ning, He, Suhao, zhao, Yuxin, Yixiao, Li, Shen, Ye

Analysis of In-Cylinder Flow for Hybrid Gasoline Engine using High-Speed Particle Image Velocimetry

2026-01-0298To 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

Study on the Regulation of the Three-Phase Microenvironment in Low-Platinum MEA

2026-01-0443To be published on 04/07/2026

With the growth of energy demand, fuel cells as efficient and clean energy devices, have attracted increasing attention. However, the high cost of membrane electrode assembly (MEA) restricts their large-scale application. Therefore, reducing the platinum usage and improving performance have become key research point. In this work, MEA was prepared and excellent performance of 1.52 W·cm-2 was achieved at a low platinum loading. The influence of different ionomer/carbon (I/C) ratio on the performance of fuel cells was systematically investigated. It was found that the performance of the MEA was the highest when the I/C ratio is 0.6. Quantifying hydrophilic and hydrophobic characteristics of catalyst layers with varying ionomer contents revealed that the proton conduction efficiency is optimal when the I/C ratio is 0.6. This balance established efficient proton conduction pathways, from the results of proton conduction impedance testing. SEM analysis demonstrated that pore structure

Li, Xin, Cai, Xin, Lin, Rui

Potential for Total Cost of Ownership Reduction using Passive Pre-Chamber Ignition in Natural Gas Engines

2026-01-0309To be published on 04/07/2026

Spark plug durability is a factor affecting the total cost of ownership (TCO) of spark-ignited natural gas engines, with some heavy-duty platforms requiring plug replacement after only 750 hours of operation. The high ignition energy demand under lean or diluted conditions accelerates electrode wear, shortening plug life and increasing maintenance frequency. This work evaluates passive pre-chamber (PC) ignition operating at lowered spark energies as a strategy to reduce spark energy requirements and extend plug durability, thereby lowering TCO. Experiments were conducted on a medium-duty Cummins 6.7L ISB engine at 1600 RPM and 50% load under varying exhaust gas recirculation (EGR) dilution levels (0–40%). Two passive pre-chambers, with 1.1 mm and 1.6 mm nozzle diameters, were compared against conventional spark ignition (SI). SI was operated with a fixed coil dwell of 4 ms (~90 mJ), while the PC configuration was tested across 2–4 ms dwell times (~30–90 mJ). Cylinder pressure analysis

Dhotre, Akash, Voris, Alex, Okey, Nathan, Kane, Seamus, Rajasegar, Rajavasanth, Northrop, William

Neural Surrogates and Reinforcement Learning for Heavy-Duty Diesel Torque Control: A Data-Driven Alternative to PID

2026-01-0199To be published on 04/07/2026

Accurately reproducing the torque trace of regulatory drive cycles is central to heavy-duty diesel emissions certification and repeatable development testing. Conventional controllers—PI/PID with gain scheduling and feedforward mapping—can meet requirements but demand extensive hand-tuning and struggle with strong nonlinearities and time-varying delay. Building on prior work that quantified the limits and benefits of gain-scheduled and feedforward strategies under the FTP transient cycle, this work investigates a fully data-driven control framework. First, a recurrent neural network (LSTM) torque surrogate is trained on dynamometer data to capture engine dynamics from readily available signals (e.g., engine speed, commanded pedal/torque, recent torque history) and actuator constraints. Second, this learned “world model” is used to train a reinforcement learning (RL) policy that outputs pedal commands to minimize torque-tracking error while regularizing control effort and respecting

Cook, James, Puzinauskas, Paulius, Bittle, Joshua, Hall, Spencer

A Novel Development Method for a Control Model of TWC in Hybrid Electric Vehicles Based on Mechanism Simplification and Temperature Update

2026-01-0371To be published on 04/07/2026

Under increasingly stringent emission regulations, hybrid electric vehicles face heightened requirements for tailpipe emission control. Their complex operational profiles and frequent transitions between power modes pose significant challenges to experimental efforts in emission measurement and aftertreatment control, leading to substantially increased economic and temporal costs that severely constrain emission optimization. To address these challenges, this study employs the development and calibration of a high-accuracy virtual model to conduct simulation experiments that accurately replicate real-world driving conditions, significantly reducing development costs while maintaining predictive accuracy. Focusing on hybrid electric vehicles, we developed an aftertreatment model integrating catalytic reaction mechanisms and energy conservation equations, incorporating coupled temperature and concentration calculations. This model enables real-time monitoring of dynamic oxygen storage

Lian, Xuetong, Wang, Zhiao, Liu, Weiqiang, Chen, Tao

Adaptive Economic Model Predictive Control for Engine Emissions Management with Compensation for Performance Drift

2026-01-0287To be published on 04/07/2026

This paper addresses the changes in engine emissions due to in-use component changes through the synergistic application of predictive control, machine learning, and onboard adaptation. In particular, we consider an adaptive economic Model Predictive Control (eMPC) strategy to mitigate the effects of performance drift on Nitrogen Oxides (NOx) and Soot emissions from compression ignition (diesel) engines. A performance drift block, which applies a multiplier and offset to nominal emissions, is integrated with a high-fidelity Neural Network (NN) plant model to simulate these characteristic changes. To counteract variability, two online adaptation methods are integrated within the eMPC framework: One is based on Recursive Least Squares (RLS) and another on a continuously updated online NN. The proposed control architecture is validated through simulations over standard transient cycles. Results demonstrate that while the rate-based eMPC possesses inherent robustness to performance drift

ZHANG, JIADI, Li, Xiao, Kolmanovsky, Ilya, Tsutsumi, Munecika, Nakada, Hayato

The impact of various renewable hydrocarbons on performance and emissions in a super lean burn engine

2026-01-0306To be published on 04/07/2026

Biofuels can play a key role as carbon-neutral transitional energy sources for ICE vehicles as the fleet moves towards increasing electrification. Blending of ethanol plays a key role in enhancing the anti-knock properties of the fuel and also allows renewable hydrocarbons (such as bio-naphtha) to be incorporated into the blend whilst maintaining an acceptable overall fuel quality. Super lean burn ICE technology with λ between 2 and 3 can lead to significantly enhanced fuel economy and reduced NOx emissions. The Toyota prototype engine used to generate data for this project injects most of the fuel in a PFI mode to generate a homogeneous super-lean charge in the cylinder, but just before spark ignition the DI injector sprays a small amount of fuel towards the spark plug to create a richer charge near the spark plug to promote flame kernel development. Various fuel formulations with a high biofuel content were tested in both conventional and super lean burn engines. Certain fuel

Aradi, Allen, Krueger-Venus, Jens, Jain, Sandeep Kumar, Cracknell, Roger, Kolbeck, Andreas, Shibuya, Masahiko, Yamada, Ryota, Matsubara, Naoyoshi, Kitano, Koji

Sensorless Estimation of In-Cabin CO2 Concentration for Model-Based Air Recirculation Control

2026-01-0130To 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

Experimental Study on Macroscopic Characteristics of Ammonia Spray under Flash Boiling and Non-Flash Boiling Conditions with Large-Diameter single-hole Nozzles

2026-01-0339To be published on 04/07/2026

Ammonia is regarded as a potential alternative fuel, and its spray characteristics are crucial for efficient combustion in engines. For large-bore engines suitable for heavy-duty vehicles or ships, the adoption of large-diameter nozzles is expected to ensure an appropriate fuel flow rate while improving fuel-air mixing efficiency, thereby enhancing in-cylinder combustion performance. This paper conducted an experimental study on the characteristics of liquid ammonia sprays under wide thermodynamic conditions, a wide range of injection pressures, and a wide range of nozzle diameters. The study found that at room temperature, as the ambient pressure increases from 0.1 MPa to 4 MPa, the development of spray penetration slows down. However, at 0.05 MPa, the radial expansion of the near-field spray is greater, and the penetration is slightly behind that at 0.1 MPa. The liquid penetration increases with the increase in ambient temperature. This was because the increase in temperature reduced

Liu, Yi, Zhong, Jie, Hu, Yuchen, Zhu, Wuzhe, yunliang, Qi, QINGCHU, CHEN, Wang, Zhi

A Quantitative Approach for Mapping and Assessing Diesel Particulate Filter Regeneration Events in Diesel Engines

2026-01-0377To be published on 04/07/2026

Regeneration of diesel particulate filters (DPFs) is crucial for maintaining the performance of diesel engines and minimizing harmful particulate matter (PM) emissions from exhaust. However, conventional regeneration strategies often suffer from incomplete soot removal and inefficient monitoring. These issues lead to increased exhaust back pressure, reducing engine efficiency, and potentially damaging the particulate filter. In this paper, a new approach is proposed for mapping and quantifying the real-world DPF regeneration process for diesel engines complying with the stringent emission standards. We introduce a novel metric, the differential pressure drop percentage (DPDP), to detect regeneration events and quantify soot burn quality. The proposed method utilizes real-time sensor data obtained through the vehicle’s On-Board Diagnostics (OBD) system. The algorithm processes sensor data and robustly maps the regeneration quality. The performance of regeneration event detection and

Bagga, Harleen Kaur, Nagare, Mukund B., Patil, Bhushan D., Ravishankar, Hariharan, Melapudi, Vikram, Patil, Abhijit

Passive Soot Regeneration Observations on a GPF-equipped vehicle for PM exhaust emission control.

2026-01-0366To be published on 04/07/2026

The gasoline particulate filter (GPF) will be a common technology adopted by EPA Tier4 emission compliant vehicles, starting as early as model year 2017 in North America. For those Tier-4 compliant gasoline-powered powertrains, their GPF solutions will require that the captured soot can be safely removed through passive oxidation. This clean-out process is driven by occasional fuel-cut events, such as engine motoring, which would provide an excess of oxygen in the exhaust gas flow to the hot, soot-loaded GPF. Here, a study has been conducted where a modern vehicle with a 3L engine displacement was upfitted with appropriately sized GPFs for soot capture in the dual-bank exhaust line. These GPFs were weighed to track their soot-load trends between representative real-world driving routes, where sensor data and ECU parameters were recorded. Thus, characterization of the passive soot regeneration process in the GPF was linked to the preceding exposure of gaseous flow temperatures, oxygen

Craig, Angus, Warkins, Jason

Effect of renewable fuel blends on particulate emissions in warm-up conditions in a GDI engine

2026-01-0304To be published on 04/07/2026

Renewable gasoline offers significant benefits in reducing greenhouse gas (GHG) emissions. In this study, five gasolines with different renewable hydrocarbon classes and varying distillation curves were taken to investigate their effect on particle number (PN) emissions in a spark-ignition GDI engine at 10 bar indicated mean effective pressure (IMEP) and 2000 rpm. The engine coolant temperature was varied from 90°C to 35°C to investigate the effect of fuel evaporation on soot formation. Injectors with various spray plume targets and start of injection (SOI) timing (300° and 260° bTDC) were used to assess how different gasolines affect engine performance and to determine engine calibration requirements. A simplified transient cycle examines how engine motoring influences PN emissions for test gasolines. A high-speed camera and endoscope were used to identify the sources of soot during fuel combustion. Simulations were done to assess the quality of fuel-air mixing in support of the

Muniappan, Krishnamoorthi, Dahlander, Petter, Helmantel, Ayolt, Alemahdi, Nika, Lehto, Kalle

An Integrated Methodology for Sustainable Mobility Infrastructure Planning: The Atlanta Aerotropolis Case Study

2026-01-0097To be published on 04/07/2026

By the early 2020s, more than 4.5 billion people have been living in urban areas worldwide, compared to just 1 billion in 1960. Rising growth in urban populations present challenges to infrastructure and transportation systems. Higher traffic levels and reliance on conventional vehicles have contributed to heightened greenhouse gas (GHG) emissions, rising global temperatures, and irreversible environmental degradation. In response, emerging transportation solutions—including intelligent ridesharing, autonomous vehicles, zero-tailpipe-emission transport, and urban air mobility—offer opportunities for safer and more sustainable transportation ecosystems. However, their widespread adoption depends not only on technological performance and efficiency, but also on integration with current infrastructure, safety, resilience to unexpected disruptions, and economic viability. A dynamic, agent-based System-of-Systems (SoS) transportation model is developed to simulate vehicle traffic and human

Rana, Vishva, Balchanos, Michael, Mavris, Dimitri, Valenzuela Del Rio, Jose

Energy-Efficient Predictive Cruise Control in Heavy-Duty Electric Trucks with Optimization of the Penalty Factor as a Function of Payload

2026-01-0042To be published on 04/07/2026

Heavy-duty Class 8 battery electric trucks not only offer a significant reduction in greenhouse gas (GHG) emissions compared to conventional diesel trucks but can also provide significant savings in fuel costs. To further enhance the energy and freight efficiency, Predictive Cruise Control (PCC) algorithms can be developed that generate optimal acceleration profiles for the vehicle by minimizing a cost function which combines both energy consumption and deviation from the desired velocity. A critical component of the cost function is the penalty factor, which governs the trade-off between energy use and travel time, which are two conflicting objectives in freight logistics. Selecting an appropriate penalty factor is essential, as freight deliveries are time-sensitive but minimizing energy consumption remains a priority. Moreover, variations in payload significantly affect vehicle dynamics and energy usage, making it critical to adapt the penalty factor to different payload conditions

Safder, Ahmad Hussain, Villani, Manfredi, Wang, Eric, Khuntia, Satvik, Nelson, James, Meijer, Maarten, Ahmed, Qadeer

Methodology to Quantify the Petroleum Equivalent Fuel Economy Impact of BEV Thermal System Energy Consumption

2026-01-0132To be published on 04/07/2026

This paper will present research and 1D modeling results to support a proposed methodology to determine a fleet ambient weighted average Petroleum Equivalent Fuel Economy (PEFE) for the energy consumed by the thermal system of a BEV, including a proposal of how factor in the thermal system PEFE result into an OEM’s overall CAFE determination on an incentivized (not punitive) basis, within the existing regulatory framework. The topic is particularly important because EPA and NHTSA final rules issued in early 2024 eliminated A/C Efficiency Credits for BEVs that are currently in place for all classes of light duty vehicles. However, without some sort of regulatory incentivization, market forces will dictate thermal comfort system solutions that consume more energy – and with that more negative secondary effects such as higher greenhouse gas emissions and vehicle mass - than would otherwise be the case. Eliminating incentivization for BEVs is particularly concerning because the thermal

Taylor, Dwayne

Comparison of Ammonia Emission Characteristics Between Different Gasoline Vehicles Equipped with Three-Way Catalysts

2026-01-0374To be published on 04/07/2026

In recent years, the tightening of vehicle emission regulations has led to a decreasing trend in regulated pollutants such as NOₓ and CO. However, the emission of ammonia (NH₃), which is unintentionally generated during the purification process in three-way catalyst of gasoline vehicles, has become a growing concern. NH₃ emissions from vehicles can serve as a precursor to PM2.5 and have been reported to cause local roadside pollution. Therefore, there is a growing need for on-road testing to identify conditions under which NH₃ is likely to be emitted. Furthermore, since engine control strategies vary among vehicle types, it is desirable to consider differences in emission behavior across different models. In this study, on-road NH₃ emissions were measured for multiple vehicle models with different powertrains, and the effects of engine behaviors and engine operating duration across vehicles on NH₃ emissions were investigated. To analyze differences in NH₃ emission behavior among

Ashizawa, Keigo, Fukunaga, Chisato, Gao, Tianyi, Sato, Susumu

Optimal Vehicle Sampling for Fleet-Wide Emissions Monitoring using Submodular Maximization

2026-01-0283To be published on 04/07/2026

This article addresses the problem of optimal vehicle sampling for fleet-wide in-use emissions monitoring, a necessity driven by the absence of direct emissions sensors in modern production vehicles and the variable impact of in-use changes and operational factors (mileage, time-in-service, workload) on emissions performance across a fleet. Recognizing that comprehensive fleet testing is impractical due to significant downtime and cost, we propose a novel approach to identify a small, yet optimally informative subset of vehicles for sampling. The proposed approach leverages submodular function maximization, a technique rooted in optimal experimental design, specifically D-optimal design, to maximize the determinant of the information matrix (e.g., of $X^TX$, where $X$ is the regressor/design matrix in the case of a linear in parameters model). This approach ensures that the collected data yields maximum information for refining and building accurate models for emissions characteristic

ZHANG, JIADI, Li, Xiao, Kolmanovsky, Ilya, Tsutsumi, Munecika, Nakada, Hayato

1D System Evaluations for Efficiency Trade-offs for a Heavy-Duty H2ICE Concept

2026-01-0274To be published on 04/07/2026

Lean H2 combustion strategies have shown promising gross thermal efficiency and ultra-low engine-out NOx emissions for H2-fuel based internal combustion engine (H2ICE) systems in heavy-duty (HD) transport. Implementing lean combustion strategies require excessive air flow demand that further increases with the engine load increase. To meet such air flow demands efficiently across a wide engine operating region, a detailed system optimization is warranted including next-generation turbocharging systems. In this 1D system analysis campaign, a detailed study of various air-system configurations was conducted for a modified HD, direct-injection (DI), H2ICE concept based-off a Cummins heavy-duty 15L engine. The concept engine configuration had a geometric compression ratio of 10.4 and possessed no external exhaust gas recirculation (EGR). First, a calibrated 1D engine model representing the H2ICE concept was developed. Using the 1D model, a detailed system-level analysis was conducted at

Kumar, Praveen, Sari, Rafael, Merritt, Brock, Popuri, Sriram

Technical Outlook on the Potential of HVO and Biodiesel Blends for Cleaner Combustion

2026-01-0316To be published on 04/07/2026

The increasing need to decarbonize the transport sector is accelerating the adoption of renewable fuels, particularly biofuels, as sustainable alternatives to conventional diesel. For compression ignition engines, Hydrotreated Vegetable Oil (HVO) represents a promising solution due to its clean combustion profile and high-quality fuel properties. HVO is a paraffinic fuel obtained via hydrotreatment of renewable lipids. It is characterized by a high cetane number (>70), very low particulate emissions, and excellent oxidative stability. However, the absence of polar molecules results in poor lubricity, which raises durability concerns for high-pressure fuel systems. Biodiesel, composed of fatty acid methyl esters (FAME) derived from vegetable oils or used cooking oil, is known for its renewable origin and favorable lubricity. Its ester content enhances lubricity and contributes to reductions in carbon monoxide (CO), unburned hydrocarbons (HC), and particulate matter. Nonetheless

Zaccai, Martina, Chiavola, Ornella, Palmieri, Fulvio, Verdoliva, Francesco

Study of Deposit Control Additive Efficacy in Gasoline Direct Injection Engines

2026-01-0349To 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

Persistent Elevated Soot Emissions Induced by Clustered Stochastic Preignition Events

2026-01-0314To be published on 04/07/2026

Stochastic Preignition (SPI) is an abnormal combustion phenomenon that can occur in spark-ignition engines particularly under high-load operation. SPI is characterized by uncontrolled initiation of combustion prior to spark discharge, an abnormal combustion process that can lead to severe knock events and significant engine damage. SPI has been associated with fuel properties, lubricant composition, and engine design and operation. In this work, a single-cylinder test engine with a dry-sump oil system was utilized to study the SPI response of E10 and E25 fuels with a range of Reid Vapor Pressure (RVP). An automated test procedure was employed, consisting of ten square-waved load profile segments, with each segment composed of 5 min of low-load operation followed by 25 min of sustained high-load operation. These tests were replicated across multiple days of testing with a triple flush of lubricant between each test, and an online Fuel in Oil diagnostic measurement. Exhaust particulate

Splitter, Derek, Jatana, Gurneesh, DelVescovo, Dan, Douvry-Rabjeau, Julien, Fioroni, Gina, Chapman, Elana, Salyers, John

Impact of Hydrothermal Aging and Chemical Poisoning on NOx Reduction Performance of SCR – A Simulation Study

2026-01-0372To be published on 04/07/2026

Diesel aftertreatment systems continue to play a critical role in compliance of tailpipe criteria pollutant compliance for commercial transportation applications. Quantification of performance of the aftertreatment system in particular Selective Catalytic Reduction component as a function of aging is critical in ensuring real world tailpipe NOx standard for aged systems. As part of A2CAT-II consortium at Southwest research Institute this aspect of the production AT system was studied for different aging conditions using a set of DAAAC (Diesel Aftertreatment Accelerated Aging Cycle) aged components. The performance of these aged components was quantified through a set of steady state reactor tests and transient ECTO burner lab tests that simulate on engine performance. The data was collected at 0, 33, 66 and 100% equivalent aging conditions and this data was used to develop a GT suite-based model with a set of inhibition factors to simulate the loss of Ammonia Storage Capacity and

Chundru, Venkata Rajesh

Model-based Development of a Heavy-Duty H2-ICE and Integrated, Turbogeneration, Electrification, and Supercharging (ITES) System

2026-01-0426To 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

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