Browse Topic: Particulate matter (PM)

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Impact of Water Injection on Emission Formation in an HVO-fuelled NRMM Engine2025-32-006711/03/2025
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 analysed in comparison to diesel operation. 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 John Deere 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 high load. The focus of the
Fuhrmeister, Jonas, Mayer, Sebastian, Günthner, Michael
Emission Performance of Motorcycles: Regulated and Non-Regulated Pollutants under Harmonized and Extended Testing Conditions2025-32-006911/03/2025
This study investigates emissions from motorcycles, focusing on both regulated gaseous pollutants (e.g., CO, NOx, HC) and particulate number (PN) emissions, which are non-regulated for this vehicle category in the actual EU emission regulation. Using a state-of-the-art testbench setup equipped with advanced exhaust gas analysis and PMP system, emissions were analyzed under both standardized homologation cycles and more dynamic Real Driving Cycles (RDCs). Besides the measurement results the technological differences between different motorcycle categories are described. This is followed by a discussion of the influences of engine and exhaust gas aftertreatment systems on emission. The findings reveal that, there are two different subcategories of two-wheeler, which show different emission characteristics. L1e vehicles showed increased emissions compared to passenger cars, caused by the absence of advanced exhaust aftertreatment and on-board diagnosis systems which is driven by less
Schurl, Sebastian, Schmidt, Stephan, Bretterklieber, Niko, Kupper, Martin, Kirchberger, Roland
Predicting Transient Soot Emissions in Diesel Engines Using Physical and Machine Learning Models2025-32-001711/03/2025
In recent years, emissions regulations for engines have been globally strengthened, and many countries, including the United States, have added real-world testing using Portable Emissions Measuring Systems (PEMS) as new test requirements. In the development of diesel engines, improving fuel efficiency and simultaneously reducing NOx and soot emissions are critical challenges, and evaluations using Model-Based Development (MBD) are considered promising methods. However, it is still difficult to accurately predict soot emission, even with detailed combustion models using computationally intensive 3D-CFD, due to the complex mechanisms of soot formation. While various approaches have been researched for prediction methods, they are often limited to specific injection and operating conditions, and an industry-standard model has to be established yet. This paper presents a method for predicting NOx and soot emissions in diesel engines under arbitrary transient test cycles. Fuel consumption
Kitamura, Takahiro, Matsuoka, Ayano, Suematsu, Kosuke, Okano, Hiroaki
Enhancing Cabin Air Quality: Challenges, Impact and Advanced Climate Control Solutions2025-28-043310/30/2025
Cabin air quality plays a crucial role in ensuring passenger comfort, health and driving experience. There have been growing concerns over poor cabin air quality resulting from multiple factors, including infiltration of external pollutants such as particulate matter, volatile organic compounds, emissions from vehicle interior materials, microbial contamination and inadequate ventilation. Therefore, maintaining optimal air quality inside vehicle cabin has become a critical aspect of vehicle climate control systems. Additionally, high humidity levels inside the cabin contribute to mold growth and fogging of windows, further compromising both air quality and visibility. This review explores such factors contributing to poor cabin air quality, where the severity of these issues ranges from mild discomfort and allergic reactions to long-term respiratory ailments. To mitigate these challenges, automotive manufacturers and researchers have implemented various air purification and filtration
Sharma, Shrutika
First Investigation of Ducted Fuel Injection on a Retrofitted Heavy-Duty Multi-Cylinder Production Engine04-19-01-000510/22/2025
Ducted fuel injection (DFI) was tested for the first time on a production multi-cylinder engine. Design-of-experiments (DoE) testing was carried out for DFI with a baseline ultra-low sulfur diesel (ULSD) fuel as well as three fuels with lower lifecycle carbon dioxide (CO2) emissions: renewable diesel, neat biodiesel (from soy), and a 50/50 blend by volume of biodiesel with renewable diesel denoted B50R50. For all fuels tested, DFI enabled simultaneous reductions of engine-out emissions of soot and nitrogen oxides (NOx) with late injection timings. DoE data were used to develop individual calibrations for steady-state testing with each fuel using the ISO 8178 eight-mode off-road test cycle. Over the ISO 8178 test, DFI with a five-duct configuration and B50R50 fuel reduced soot and NOx by 87% and 42%, respectively, relative to the production engine calibration. Soot reductions generally decreased with increasing engine load. Hydrocarbon and carbon monoxide emissions tended to increase
Ogren, Ryan M., Baumgard, Kirby J., Radhakrishna, Vishnu, Kempin, Robert C., Mueller, Charles J.
Characterization of High-Power Cold-Start Emissions Part 2: Impact of Hybrid Topologies and Powertrain Sizing on Tailpipe Emissions Performance03-18-06-003910/22/2025
The current work is the second installment of a two-part study designed to understand the impact of high-power cold-start events for plug-in electric vehicles (PHEVs) on tailpipe emissions. In part 1, tailpipe emissions and powertrain signals of a modern PHEV measured over three drive cycles identified that high-power cold-start events generated the highest amounts of gaseous and particulate emissions. The trends in emissions data and powertrain performance were specific to the P2-type hybrid topology used in the study. In this second part of the study, the effects of different PHEV hardware configurations are determined. Specifically, the tailpipe emissions of three production plug-in hybrid vehicles, operated over the US06 drive cycle, are characterized. The approach compared the tailpipe emissions of the test vehicles on the basis of the hybrid topologies and corresponding engine operational characteristics during a high-power cold-start event. Analysis of test results showed
Chakrapani, Varun, O’Donnell, Ryan, Fataouraie, Mohammad, Wooldridge, Margaret
The Aircraft nvPM Mission Emissions Estimation Methodology, Version 2 (MEEM2)2025-01-600010/13/2025
The nvPM Mission Emissions Estimation Methodology (MEEM) was previously developed to estimate nonvolatile particulate matter (nvPM) emissions from ground certification data using the publicly available data from the International Civil Aviation Organization (ICAO) Aircraft Engine Emissions Databank (EEDB). In order to potentially improve the accuracy of nvPM emissions estimation and to enhance its usefulness to modelers, the method was revised to make use of fuel flow correlations and similar altitude corrections as used in the Boeing Fuel Flow Method 2 (BFFM2). The new fuel flow approach allows for improved trade-off-type assessments between nvPM and gaseous emissions—i.e., less relative uncertainties when assessing results from the two methods. Like the former MEEM, the new method, MEEM2, can be used with just publicly available data such as nvPM emissions indices (EI) from the EEDB as well as predicted fuel flows from publicly available aircraft performance models. MEEM2 has been
Ahrens, Denise, Kim, Brian, Méry, Yoann, Zelina, Joseph, Dudebout, Rudolph, Miake-Lye, Richard C.
Automated Calibration of Heavy-Duty Low NO x Aftertreatment System Controls using Deep Learning and Global Optimization Methods2025-01-040210/07/2025
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
A Novel Simulation Method for Vehicle Brake Wear Emissions2025-01-036109/15/2025
The effective reduction of particulate emissions from modern vehicles has shifted the focus toward emissions from tire wear, brake wear, road surface wear, and re-suspended particulate emissions. To meet future EU air quality standards and even stricter WHO targets for PM2.5, a reduction in non-exhaust particulate (NEP) emissions seems to be essential. For this reason, the EURO 7 emissions regulation contains limits for PM and PN emissions from brakes and tire abrasion. Graz University of Technology develops test methods, simulation tools and evaluates technologies for the reduction of brake wear particles and is involved in and leads several international research projects on this topic. The results are applied in emission models such as HBEFA (Handbook on Emission Factors). In this paper, we present our brake emission simulation approach, which calculates the power at the wheels and mechanical brakes, as well as corresponding rotational speeds for vehicles using longitudinal dynamics
Landl, Lukas, Ketan, Enis, Hausberger, Stefan, Dippold, Martin
Achieving Euro 7 Compliance: Cost-Effective Brake Wear Particle Emissions and Performance with FNC-Smart ONC® GCI Rotors2025-01-033209/15/2025
Advanced ferritic nitrocarburizing process combined with a specialized post-oxidation treatment described as FNC + Smart ONC® [1] is developed for brake rotor applications. The process can be applied to standard grey cast iron brake rotors, significantly reducing PM 10 emissions to levels below the Euro 7 limits for most vehicles equipped with at least some recuperative braking capabilities, all without compromising performance. Finished grey iron brake rotors, ferritic nitrocarburized and post oxidized were evaluated according to several industry standards. The standards include SAE J2707B (Block Wear Test including Highway) [2], GRPE-90-24 Rev.1 Emission Test (Full WLTP Brake Cycle 6 Times) [3], and SAE J2522 (AK-Master Performance) [4]. Nitrocarburized post oxidized brake rotors were compared to untreated grey iron rotors exposed to several friction materials. Ferritic nitrocarburizing and post oxidation addresses the issue of corrosion, which is particularly relevant for brake
Winter, Karl-Michael, Holly, Mike
Challenges in Quantifying Tire Wear Particle Emissions on an Outer Drum Test Bed2025-01-035209/15/2025
Tire wear is a significant source of microplastics and airborne particulate matter, contributing to environmental pollution and posing health risks. This study aims to develop a reliable method for quantifying tire wear and TWP on an outer drum test bed while achieving realistic wear rates. A degumming method using talcum powder was applied to prevent tire adhesion, which significantly increased wear rates but introduced complications in particle measurements. To address this, a flow-optimized enclosure was implemented to minimize background emissions. Particle emissions were quantified using APCs, PM samplers, and an ELPI+. The results underscore the challenge of distinguishing between TWP and talcum powder contributions. To estimate the percentage of airborne particle mass, a novel method was employed that calculates the RGB values of images of PM filters. This method estimates the blackening of the filter to determine the amount of TWP present. Size distribution analysis revealed
Schubert, Ludwig, Arias Torres, María Alejandra, Bigl, Stephan, Steiner, Gerald, Huber, Michael, Lex, Cornelia
Experimental Simulation of a Real Mission for Identifying a Telematics-Based Diagnostic Model in Connected Light Commercial Vehicles2025-24-012409/07/2025
Remote monitoring of commercial vehicles is taking an increasingly central position in automotive companies, driven by the growth of the on-road freight transportation sector. Specifically, telematics devices are increasingly gaining importance in monitoring powertrain operability, performance, reliability, sustainability, and maintainability. These systems enable real-time data collection and analysis, offering valuable support in resolving issues that may occur on the road. Moreover, the fault codes, called Diagnostic Trouble Codes (DTCs), that arise during actual road driving constitute fundamental information when combined with several engine parameters updated every second. This integration provides a more accurate assessment of vehicle conditions, allowing proactive maintenance strategies. The principal goal is to deliver an even faster response for resolving sudden issues, thus minimizing vehicle downtime. High-resolution data transmission and failure event information
D'Agostino, Valerio, Cardone, Massimo, Mancaruso, Ezio, Rossetti, Salvatore, Marialto, Renato
DLR Tire and Road Wear Particle Emission Testing Methodology–Collection System Influence and Repeatability Assessments2025-24-009209/07/2025
Tire and road wear particles (TRWP) have emerged as air quality hazardous matters and significant sources of airborne microplastic pollution, contributing to environmental and human health concerns. Regulatory initiatives, such as the Euro 7 standards, emphasize the urgent need for standardized methodologies to quantify TRWP emissions accurately. Despite advancements in measuring tire abrasion rates, critical gaps persist in the characterization of airborne TRWP, particularly regarding the influence of collection system design and influencing parameters on measurement accuracy and repeatability. This study addresses these challenges by designing a controlled methodological framework that aims to minimize the influencing effects and ensure comparability in TRWP emission quantification results. At the German Aerospace Center (DLR) dynamometer testbench in Stuttgart, Germany, a methodical framework was established to ensure the repeatability and comparability of TRWP measurements
Celenlioglu, Melis Seren, Epple, Fabius, Reijrink, Nina, Löber, Manuel, Reiland, Sven, Vecchi, Roberta, Philipps, Franz
S.I.S.T.E.R.: An Integrated Approach to Non-Exhaust Emissions2025-24-009109/07/2025
As electric mobility spreads and evolves, non-exhaust Particulate Matter (PM) sources are gaining more attention for total vehicular emissions. A holistic approach for studying the involved phenomena is necessary to identify the parameters that have the greatest impact on this portion of emissions. To achieve this, it is necessary to develop a new platform capable of both creating testing methodologies for future regulations and enabling the parallel development of advanced tyres and brakes that meet these standards, by correlating vehicle dynamics, driving style, tyre and brake characteristics, and the resulting emissions. Here the authors present the Sustainable Integrated System for Total non-Exhaust Reduction (S.I.S.T.E.R.) project, funded by the Italian Centro Nazionale per la Mobilità Sostenibile (MOST), that aims to develop an integrated approach to study tyre/brake-related emissions from the initial stages of compound development to outdoor vehicle tests, allowing actions to be
Genovese, Andrea, De Robbio, Roberta, Lenzi, Emanuele, Caiazza, Antonio, Lippiello, Felice, Costagliola, Maria Antonietta, Marchitto, Luca, Serra, Antonio, Arimondi, Marco, Bardini, Perla
AeroSolfd: Advancing Air Quality through Retrofitted Gasoline Particulate Filters – Insights from Laboratory and Real-World Evaluations2025-24-008809/07/2025
This article details the experimental and testing activities of the EU project AeroSolfd, with a particular focus on the project's efforts to reduce combustion-based nanoparticle emissions in exhaust gases for the European fleet of vehicles by developing a GPF retrofit solution. The technical activities undertaken the process of developing such a retrofit are examined in this article. The findings illustrate the viability of reducing nanoparticle levels in gasoline-powered vehicles with the utilization of appropriate GPFs. For this purpose, in addition to a fleet, four vehicles were examined in great detail and underwent the process of obtaining component approval for the particulate filter. The vehicles were measured in a preliminary state, then following the installation of the GPF, and subsequently after several months of continuous field operation. A total of four vehicles were selected for evaluation as a representative subgroup of a larger test fleet of vehicles in the project
Engelmann, Danilo, Mayer, Andreas, Comte, Pierre, Rubino, Lauretta, Larsen, Lars
Visualization Analysis of Hydrogen Combustion Triggered by Non-Controlled Hotspots Using a Rapid Compression Expansion Machine2025-24-004709/07/2025
Research on hydrogen-fueled internal combustion engines has gained growing attention as a carbon-neutral solution to reducing emissions in the transport sector. However, challenges remain, with the risk of abnormal combustion being one of the major criticalities. This paper aims to clarify the ignition process of a hydrogen-air mixture caused by lubricant oil droplets and soot deposition. To achieve this, high-speed imaging methods were applied with a Rapid Compression Expansion Machine under engine-like conditions. Direct imaging and OH* chemiluminescence were captured simultaneously on the engine head to visualize the ignition point and flame propagation. Different operating conditions were tested to evaluate the influence of lambda, intake pressure, and soot quantity on ignition occurrence. For each test bench configuration, ten successive tests were conducted to assess the probability of ignition. The presence of soot was ensured through a preliminary run with diesel injection. The
Tempesti, Claretta, Yukitani, Takumi, Horibe, Naoto, Romani, Luca, Ferrara, Giovanni, Kawanabe, Hiroshi
Influence of the SCR Reactivity on Passive Soot Oxidation for Vanadium-Coated and Uncoated (S)DPF2025-24-008609/07/2025
In modern diesel exhaust aftertreatment systems (EATS), combining a catalytic coating for selective NOx reduction (SCR) with a diesel particulate filter (DPF) enables simultaneous particulate filtration and NOx reduction. In such systems, soot regeneration is primarily influenced by the NO2 supply in the exhaust gas, particularly at low exhaust temperatures (250-400 °C). Several investigations found that in SCR-coated filters with urea-water solution (UWS) dosing upstream, particle oxidation is partially inhibited by NH3. However, at higher temperatures (>400 °C), this effect seems to be reduced. In this study, numerical modelling approaches based on engine test bench results are utilised to examine the impact of SCR reactivity on passive soot oxidation for a highly porous vanadium-coated SDPF. To identify the interaction mechanism between the SCR reaction and soot oxidation, further investigations were conducted using a filter with a washcoat without SCR-active component. The
Prchal, Niklas, Wegmann, Andreas, Müller, Werner, Günthner, Michael
Comparison of Ignition Modes to Enable Ammonia Combustion Engines: Dual Fuel, Multi-Spark and Pre-Chamber2025-24-000509/07/2025
This study presents a CFD-based evaluation of ignition strategies for enabling ammonia combustion in a light-duty internal combustion engine. The model was first validated against experimental data for both pure ammonia spark ignition and dual-fuel ammonia-diesel compression ignition cases. Upon validation, three ignition strategies were investigated: dual-fuel compression ignition with sixty percent ammonia energy fraction, and multi-spark and passive pre-chamber ignition under stoichiometric conditions. Simulations were used to assess combustion phasing, efficiency, and emissions characteristics. The dual-fuel mode enabled stable ignition but resulted in incomplete combustion, with three-dimensional contours revealing that central regions of the chamber remained largely unburned, contributing to high ammonia slip and highlighting the need for further optimization of spray targeting and combustion chamber design. The multi-spark strategy achieved the highest efficiency through rapid
Shafiq, Omar, Menaca, Rafael, Liu, Xinlei, Uddeen, Kalim, Tang, Qinglong, Turner, James, Im, Hong G.
Study of a CI Engine for Off-Road Application in Diesel-Hydrogen Dual Fuel Configuration2025-24-005509/07/2025
Hydrogen as fuel in internal combustion engines is a promising solution for reducing greenhouse gas emissions, as its combustion produces only water vapor. One potential application is in dual fuel (DF) engines, where diesel is used to ignite the mixture, and hydrogen serves as the primary fuel. However, there is limited literature on the use of hydrogen in compression ignition (CI) engines for off-road applications running in dual fuel diesel/hydrogen, which motivates this study. The focus is on a 3-cylinder, 1-liter naturally aspirated (NA) engine with a compression ratio of 17.5:1 equipped with direct injection (DI) for diesel. Retrofitting the engine with 3 port fuel injectors, it was possible to feed the engine with hydrogen by the control system elaborated in the laboratory. The study aims to analyze dual fuel diesel/hydrogen combustion characteristics and the emissions across different engine speeds (from 1600 rpm to 3600 rpm) and loads (30%, 50% and 70%). The dual fuel
Gelé, Raphaël, Mancaruso, Ezio, Rossetti, Salvatore, Rousselle, Christine, Brequigny, Pierre
Analysis of Combustion Characteristics and Performance of a Multi-Cylinder Engine Operating on Syngas/Diesel in Dual-Fuel Mode2025-24-004209/07/2025
Despite improvements in internal combustion engine efficiency, fossil fuel reliance remains a challenge for sustainable energy. Syngas, a hydrogen-carbon monoxide mixture produced from gasification, typically of carbon-based feedstocks, offers a viable transitional fuel due to its compatibility with existing combustion technologies and reduced emissions. However, its low ignition propensity elevated intake temperatures or pressures, a limitation that can be overcome through diesel pilot injection in dual-fuel engine configurations. This study extends prior single-cylinder research to a 1.6 L four-cylinder HCCI engine operating in dual-fuel mode, resembling a Reactivity Controlled Compression Ignition (RCCI) engine. The analysis focuses on cylinder-to-cylinder combustion variation, thermal efficiency, and pollutant emissions, with particular emphasis on the influence of diesel pilot injection timing. Experimental evaluations are conducted across a range of injection timing and Syngas
El Younsi, Laila, Nelson-Gruel, Dominique
Numerical Study of Mixing, Combustion and NOx Emissions in a DI High Performance Hydrogen Engine Operated at Stoichiometry2025-24-001009/07/2025
The roadmap towards carbon neutrality by 2050 makes necessary drastic reduction of road vehicle tailpipe carbon emissions. One viable approach to reach the abatement of carbon monoxide and dioxide is to fuel internal combustion engines (ICEs) with hydrogen. The burning of a hydrogen-air mixture inside the combustion chamber reduces to minimal amount the production of carbon emissions and particulate matter that are only produced by the presence of lubricant oil. However, the high temperatures reached by the end-gases promote the formation of nitrogen oxides. In high-performance ICEs, the pursuit for high-specific power by means of the adoption of stoichiometric mixtures is hindered by the need to reduce NOx - as this pollutant drastically drops when moving towards ultra-lean mixtures. The paper aims to present a CFD-3D framework to simulate the full engine-cycle of a high-performance Spark-Ignited (SI) Direct-Injection (DI) ICE fuelled at stoichiometric conditions. The methodology is
Baudone, Antonio Denny, Marini, Alessandro, Sfriso, Stefano, Falcinelli, Francesco, Mortellaro, Fabio, Tonelli, Roberto, Breda, Sebastiano
The VERT GPF-Retrofit Program for Cleaner Urban Mobility within the HORIZON Europe AeroSolfd Project2025-24-009509/07/2025
Launched in 2022, AeroSolfd, a HORIZON Europe project, aims to advance clean urban mobility by developing affordable and sustainable retrofit solutions for gasoline vehicles. This three-year initiative addresses not only tailpipe emissions but also brake emissions and pollution in semi-enclosed environments. Within AeroSolfd, the Swiss-based VERT association focuses on reducing tailpipe emissions using state-of-the-art Gasoline Particulate Filter (GPF) technology featuring an uncoated ceramic multicell wall-flow filter. VERT, in partnership with HJS, CPK, BFH, developed and tested a GPF-retrofit system at Technology Readiness Level 8 (TRL 8). Results demonstrate over 99% filtration efficiency for particles smaller than 500 nm on standard cycles (WLTC) and real-world driving cycles (RDE). Forty-two gasoline vehicles (GDI and PFI) were retrofitted with the GPF retrofit across Germany, Switzerland, Israel, and Denmark over a 6 to 8-month operational period. No issues were observed with
Rubino, Lauretta, Mayer, Andreas C., Lutz, Thomas W., Czerwinski, Jan, Larsen, Lars C.
Experimental and Numerical Insights on Emissions Control with a Diesel Oxidation Catalyst in Reactivity-Controlled Compression Ignition Combustion Conditions03-18-05-003409/01/2025
Reactivity-controlled compression ignition (RCCI), a low-temperature combustion strategy, reduces oxides of nitrogen (NOx) and soot simultaneously; however, high concentrations of carbon monoxide (CO) and total hydrocarbons (THC) and low exhaust gas temperatures pose a significant challenge for the catalytic control of tailpipe CO and THC. Diesel oxidation catalyst (DOC) is generally used in compression ignition (CI) engines for CO, THC, and nitric oxide (NO) oxidation. This work provides a new understanding of the performance characteristics of a DOC in the RCCI combustion strategy with various gasoline–diesel fuel premix ratios ranging from ~46% to ~70% at steady-state operating conditions. Experimental insights from the RCCI strategy prompt considerations of both CO and THC oxidations and THC trap functionalities in the 1D transient model of the DOC. It is observed that an increase in the fuel premix ratio from 50% to 70% in RCCI shifts the CO and THC oxidation characteristics
Suman, Abhishek, Sarangi, Asish Kumar, Herreros, Jose Martin
Effect of Ammonia Proportion on the Combustion and Emissions in Ammonia/Diesel Dual-Fuel Engines2025-01-505507/21/2025
This article develops a numerical simulation framework for ammonia/diesel dual-fuel combustion using CONVERGE software. The modeling approach is explained in detail, including theories of numerical computation, mathematical submodels, modeling methodologies, and boundary condition specifications. Based on the developed model, this work investigates the impact of the ammonia fuel ratio on some key combustion and emission characteristics: heat release dynamics, distribution of the in-cylinder temperature field, formation of intermediate combustion species, and pollutant emissions. It provides comprehensive analysis in terms of in-cylinder pressure, mean temperature, heat release rate profile, cumulative heat release, fluctuations in the compositions of n-heptane and ammonia, distribution of the equivalence ratio, turbulent kinetic energy, concentration of OH radicals, formation of formaldehyde, and emissions of pollutants including CO, NOx, N2O, soot, and unburned hydrocarbons (HC) with
Yu, Wenbin, Wang, Haoyu, Liang, Shuaibo, Wang, Shuning
Ethanol Fuel as Enabler for High-Efficiency and Low-Soot Combustion in Dual-Fuel and Blend Modes03-18-04-002807/16/2025
Global climate initiatives and government regulations are driving the demand for zero-carbon tailpipe emission vehicles. To ensure a sustainable transition, rapid action strategies are essential. In this context, renewable fuels can reduce lifecycle CO2 emissions and enable low-soot and NOx emissions. This study examines the effects of renewable ethanol in dual-fuel (DF) and blend fueling modes in a compression ignition (CI) engine. The novelty of this research lies in comparing different combustion modes using the same engine test rig. The methodology was designed to evaluate the characteristics of various injection modes and identify the inherent features that define their application ranges. The investigation was conducted on a single-cylinder engine equipped with state-of-the-art combustion technology. The results indicate that the maximum allowable ethanol concentration is 30% in blend mode, due to blend stability and regulatory standards, and 70% in DF mode, due to combustion
Belgiorno, Giacomo, Ianniello, Roberto, Di Blasio, Gabriele
Drop-In Performance of Propyl- and Butyl-Terminated Oxymethylene Ethers in a Compression Ignition Engine04-19-01-000307/16/2025
Oxymethylene ethers (OMEs) have been proposed for use in diesel engines as a high-reactivity fuel with reduced soot emission. Historically, the focus on methyl-terminated OMEs has limited drop-in applicability. In this work, a set of extended-alkyl OMEs with methyl, propyl, and butyl terminations are tested in an unmodified 4.5L Deere diesel engine, neat and in various blends with ultra-low-sulfur diesel (ULSD). Engine operability and emissions data are collected for the various fuel blends. External laboratory testing against the ASTM D975 standard demonstrates that a blend of 30% butyl-terminated OMEs with ULSD meets all ASTM standard requirements except lubricity. It is shown that the OMEs and OME–diesel blends demonstrate shorter combustion durations, as defined by the 10%–90% heat release timing, than the ULSD control. Engine brake efficiency is unaffected by OME usage, while specific fuel consumption increases in proportion to the reduced heating values of OMEs. Particulate
Lucas, Stephen P., Zdanowicz, Andrew, Wolff, Wyatt W., Windom, Bret
In Situ Observation of Different Soot Layers in a Model Filter Channel during Its Regeneration2025-01-031207/02/2025
In order to comply with increasingly stringent emission regulations and ensure clean air, wall-flow particulate filters are predominantly used in exhaust gas aftertreatment systems of combustion engines to remove reactive soot and inert ash particles from exhaust gases. These filters consist of parallel porous channels with alternately closed ends, effectively separating particles by forming a layer on the filter surface. However, the accumulated particulate layer increases the pressure drop across the filter, requiring periodic filter regeneration. During regeneration, soot oxidation breaks up the particulate layer, while resuspension and transport of individual agglomerates can occur. These phenomena are influenced by gas temperature and velocity, as well as by the dispersity and reactivity of the soot particles. Renewable and biomass based fuels can produce different types of soot with different reactivities and dispersities. Therefore, this study focuses on the influences of soot
Desens, Ole, Hagen, Fabian P., Meyer, Jörg, Dittler, Achim
Method for Externally Controlled Availability of Lubricating Oil in Internal Combustion Engines2025-01-030207/02/2025
Reduced raw emissions from internal combustion engines (ICE) are a key requirement to reach future green-house-gas and pollutive emissions regulations. In parallel, to satisfy the need for increased engine efficiencies, the friction losses of ICEs gains attention. Measures to reduce parasitic drag inside the piston assembly such as reduced piston-ring pretension or thinner grade engine oils may increase oil ingress into the combustion chamber. The oil ingress is known to imply increased particle emissions directly counteracting the raw emission reduction target of engine development. To resolve this target conflict, the transport mechanisms of oil into the combustion chamber are the topic of current research. Specially developed research engines featuring a vertical optical window come with big potential to visualize the phenomena of the oil behavior inside the piston assembly group. Such ‘glass-liner’ engines play a pivotal role in identification and quantification of local and global
Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion2025-01-027507/02/2025
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical
Herkenrath, Ferris, Lückerath, Moritz, Günther, Marco, Pischinger, Stefan
Research on Combustion Characteristics of Flash-Boiling Spray in Cylinders Based on Machine Learning Methods2025-01-020506/16/2025
With the increasing number of vehicles in operation, exhaust emissions from engines have exerted negative impacts on ecological environments, prompting researchers to actively pursue cleaner and more efficient in-cylinder combustion strategies. Flash-boiling spray technology, capable of generating superior fuel atomization under relatively low injection pressures, has emerged as a promising approach for achieving performance breakthroughs in gasoline direct injection (GDI) engines. While current research primarily focuses on morphological characterization and mechanistic analysis of flash-boiling spray, there remains insufficient understanding of flame development characteristics under flash boiling spray conditions within engine cylinders. This study systematically investigates the combustion characteristics of TPRF and PRF fuels under both subcooled and flash-boiling spray conditions through the integration of image processing and machine learning methodologies. Experimental
Zhang, Weixuan, Shahbaz, Muhammad, Cui, Mingli, Li, Xuesong, Xu, Min
An Experimental Study on Aqueous Ammonia and Diesel Dual-Fuel Combustion with Ignition Improving Additives in a Compression Ignition Engine2025-01-023106/16/2025
Ammonia is a potential vector of renewably produced hydrogen for combustion systems and decarbonisation of transport. However, anhydrous ammonia has health risks and difficult to handle due to its volatility and toxicity. Therefore, a water-based solution of ammonium hydroxide (NH4OH) was proposed to investigate the potential use as a fuel in a compression-ignition engine. Ammonium hydroxide, also referred to as aqueous ammonia, is liquid phase under atmospheric conditions and, therefore, the storage of such a fuel does not require high pressure. Previous work has established that ammonium hydroxide solution could contribute to energy release during co-combustion with fossil diesel. However, the presence of water reduced combustion stability and limited the extent to which aqueous ammonia could displace diesel. In addition, the characteristics of co-combustion and pollutant emissions of burning such a fuel remain less understood. This study therefore explores the potential of using
Han, Yanlin, Hellier, Paul, Schonborn, Alessandro, Ladommatos, Nicos
Understanding How Blending Different Ratios of Renewable Fuels with Diesel Impacts the Toxicity of Exhaust Particulates to Human Health2025-01-020706/16/2025
The urgent need to decarbonise transport has increased the utilisation of renewable fuels blended with current hydrocarbons. Heavy duty vehicle electrification solutions are yet to be realised and therefore the reliance on diesel engines may still be present for decades to come. Currently, the diesel supplied to fuel stations across the UK is a 7% blended biodiesel, whilst in South Korea a 5% blend is utilised. Biodiesel is produced from renewable sources, for example, crops, waste residue, oils and biomass. Particulates from diesel combustion are known to be toxic due to the presence of polycyclic aromatic hydrocarbons (PAHs), however there is very limited understanding of blending oxygenated fuels on the toxicity of the particulates produced. PAHs are aromatic structures that can be metabolised into chemicals which can disrupt DNA replication and potentially influence cancer mechanisms if inhaled in high quantities. Soyabean methyl-ester (SME) was blended at lower ratios, e.g., 5
Hailwood, Emma, Hellier, Paul, Ladommatos, Nicos, Leonard, Martin
Evaluation of Jet Fuels on Thermal Efficiency, NO X Emissions, Particulate Matter, and Particle Size Distribution in a Heavy-Duty Compression Ignition Engine2025-01-024406/16/2025
Alternative fuels such as Fischer-Tropsch Synthesized Paraffinic Kerosene (FT-SPK) and Catalytic Hydrothermal Conversion Jet (CHCJ) are among the important sustainable aviation fuels (SAFs) for future transportation. However, these alternative fuels often vary in their characteristics, depending on their feedstock and fuel production processes. Therefore, a detailed analysis of these alternative fuels' combustion, emissions, and efficiency must be performed under controlled experiments to understand the impact of fuel properties and operating conditions. This study used a single-cylinder research engine (SCE) with a compression ratio of 17:1. Extensive operating conditions were performed to determine the effect of each fuel on the engine performance, which can be fundamentally understood by fuel properties (e.g., cetane number, heat of combustion, and density) in comparison with Jet-A fuel. The experimental setup includes high-speed data acquisition for combustion analysis and gaseous
Cung, Khanh, Miganakallu Narasimhamurthy, Niranjan, Khalek, Imad, Hansen, Greg
Comparison of Gasoline Particulate Indices Using U.S. Market Gasoline Samples2025-01-844904/01/2025
Simulated distillation (SimDis) uses wide bore capillary gas chromatography (GC) to provide a detailed volatility profile of blended gasoline. The boiling point distribution from SimDis analysis is correlated to the hydrocarbon contents of spark ignition fuels and provide the resolution necessary to characterize the compositions of the fuel. Recent publications on simulated distillation applied to spark ignition fuel reveal the merits of indexing a gasoline fuel so that it can be correlated to the tendency of particulate emissions from vehicles. With this in mind, SimDis can be a useful and quick tool in assessing the PM-formation potential of market gasolines. Heavy aromatic compounds are compounds identified as having at least 10 Carbons and 1 aromatic ring. These compounds that are present in spark ignition fuels are major contributors to vehicle particulate emissions. These compounds can be found in the higher boiling portion (T70+) of the distillation profiles. As demonstrated in
Goralski, Sarah, Geng, Pat, Dozier, Jon, Butler, Aron
Procedure for the Calculation of Non-Volatile Particulate Matter Sampling and Measurement System Penetration Functions and System Loss Correction FactorsAIR6504A (Current)04/01/2025
This SAE Aerospace Information Report (AIR) describes a method for assessing size dependent particle losses in a sampling and measurement system of specified geometry utilizing the non-volatile Particulate Matter (nvPM) mass and number concentrations measured at the end of the sampling system.1 The penetration functions of the sampling and measurement system may be determined either by measurement or by analytic computational methods. Loss mechanisms including thermophoretic (which has a very weak size dependence) and size dependent losses are considered in this method2 along with the uncertainties due to both measurement error and the assumptions of the method. The results of this system loss assessment allow development of estimated correction factors for nvPM mass and number concentrations to account for the system losses facilitating estimation of the nvPM mass and number at the engine exhaust nozzle exit plane. As the particle losses are size dependent, the magnitude of correction
E-31P Particulate Matter Committee
The Numerical Study of Methane Flame Characteristics in the Ammonia/Air Environment at Sub-Atmospheric Pressure2025-01-845004/01/2025
The low emission of carbon and minimum level of soot formation in combustion engines and turbines strategy is adopted by many countries to counteract global warming and climate change. The use of ammonia with hydrocarbon fuels can limit the formation of soot and carbon emissions due to non-carbon atoms. The current study explores the use of ammonia with air at coflow flame conditions, which was not tested before. It may give the choice for diesel cycle engines to use the ammonia either with air or fuel. The combustion and emission characteristics of methane coflow flame were studied at low pressure and air polluted by ammonia conditions. The results showed that a significant decline in carbon formation was observed when ammonia was boosted, 5-10%. The impact of sub-atmospheric pressure, 90-70 KPa, on COx development was higher than that of NH3 addition, 0-5%, thanks to the lower formation of hydroxymethylium, formaldehyde, and aldehyde radical. In the environment of lower pressure, the
Hina, Anam, Akram, M Zuhaib, Shafa, Amna, Akram, M Waqar
Combustion and Emission Performance from the Use of Acid-Catalysed Butanol Alcoholysis Derived Advanced Biofuel Blends in a Compression Ignition Engine2025-01-844504/01/2025
Low-carbon alternatives to diesel are needed to reduce the carbon intensity of the transport, agriculture, and off-grid power generation sectors, where compression ignition (CI) engines are commonly used. Acid-catalysed alcoholysis produces a potentially tailorable low-carbon advanced biofuel blend comprised of mixtures of an alkyl levulinate, a dialkyl ether, and the starting alcohol. In this study, model mixtures based on products expected from the use of n-butanol (butyl-based blends) as a starting alcohol, were blended with diesel and tested in a Yanmar L100V single-cylinder CI engine. Blends were formulated to meet the flash point, density, and kinematic viscosity limits of fuel standards for diesel, the 2022 version of BS 2869 (off-road). No changes to the engine set-up were made, hence testing the biofuel blends for their potential as “drop-in” fuels. Changes in engine performance and emissions were determined for a range of diesel/biofuel blends and compared to a pure diesel
Wiseman, Scott, Li, Hu, Tomlin, Alison S.
Impact of Oxygenated Fuel Components on Engine Performance and Particulate Emissions in Gasoline Blends2025-01-844604/01/2025
The challenges with electrification in the automotive industry have led to rethinking the decisions to ban internal combustion engines. Nonetheless, decarbonization of transportation remains a regulatory priority in many countries, irrespective of the energy source for automotive powertrains. Renewable oxygenated fuel components can help with the rapid decarbonization of gasoline fuels in the current fleet. Ethanol is one of the primary renewable components typically used for blending in gasoline primarily at 10% v/v but up to 20% v/v substitution which corresponds to 3.7 to 8.0% oxygen by mass. However, a range of oxygenates could be used instead of ethanol. This study aimed to determine if the engine could discriminate between different oxygenates in gasoline fuels blended at the same octane (RON) and oxygen levels. Oxygenates such as methyl-tert-butyl-ether (MTBE) and ethyl-tert-butyl-ether (ETBE) were considered in this study. Blends were made using a combination of n-heptane, iso
Kalaskar, Vickey, Mitchell, Robert, Pourreau, Daniel
Effect of Fuels on Compression Ignition Engine Particle Size Distribution and DPF Filtration Efficiency2025-01-850304/01/2025
A diesel engine was run on off-highway cycle sequence on nine (9) fuels and blends. Number-weighted solid particle size distribution (PSD) in the size range from 5.6 nm to 560 nm was measured at inlet and outlet of a diesel particulate filter (DPF) on a sequence of five (5) non-road transient cycles (NRTCs) and five (5) non-road steady-state cycles (NRSCs). The measurements were used to correlate the fuel properties to the DPF-In concentrations and filtration of different size particles in the DPFs. The data showed an expected trend with the DPF-In emissions. Ultra-low sulfur diesel (ULSD) had the highest solid particle number (SPN) concentrations and biodiesels (soy-based biodiesel (B100) and rapeseed-based biodiesel (RME)) had the lowest concentrations. The geometric number mean diameter (GNMD) of DPF-In PSD correlates with the concentrations. The calculated GNMD was the highest for ULSD and lowest for B100/RME. An opposite trend for the GNMD was observed at the DPF-Out where the
Lakkireddy, Venkata, Khalek, Imad, Buffaloe, Gina
Effect of Catalyst Coating Strategy on NOx Reduction and Passive Soot Oxidation for Selective Catalytic Oxidation-Selective Catalytic Reduction Catalyst on Diesel Particulate Filter2025-01-849004/01/2025
Selective catalytic oxidation/reduction catalysts coated on diesel particulate filters (SDPF) are an important technology route to meet next-stage emission regulations. The previous research of the research group showed that compared with SDPF coated with Cu-SSZ-13, the SDPF coated with novel selective catalytic oxidation-selective catalytic reduction (SCO-SCR) catalyst, which combined MnO2-CeO2/Al2O3 and Cu-SSZ-13, can simultaneously improve NOx reduction and soot oxidation performance. Catalyst coating strategy is an important parameter affecting the performance of SDPF. In this study, the effects of different coating strategies of SCO-SCR catalysts (C25, C50, C75, and C100) on the performance of NOx reduction and soot oxidation in SDPF were investigated. The results show that, as the inlet gas temperature increases, NO emissions first decrease and then increase, NOx conversion efficiency first increases and then decreases, and the rich-NO2 area, NH3 oxidation rate, N2O, CO, CO2
Chen, Ying-jie, Tan, Piqiang, Yao, Chaojie, Lou, Diming, Hu, Zhiyuan, Yang, Wenming
Gasoline Particulate Filter Modeling with Catalytic Washcoat and Ash Accumulation and Transient Soot Distribution Prediction2025-01-848304/01/2025
The upcoming EURO 7 and EPA Tier 4 regulations and the possible China 7 are expected to tighten the tailpipe particulate emissions limits significantly. High performance Gasoline Particulate Filters (GPFs) with high filtration efficiency and low pressure drop would be mandated for gasoline engines to meet these stringent regulations. Due to packaging constraints, GPFs are often coated with three-way catalyst (TWC) materials to achieve four-way functionality. Ash accumulation in GPFs also has a significant impact on the performance of GPFs. This paper utilizes 3D CFD to predict the transient filtration efficiency and pressure drop of a washcoated GPF with ash accumulation during the soot loading process. Simulation results show a decent match with experimental data. The 3D CFD model also provides detailed information on soot penetration in the GPF wall substrate and soot cake characteristics on the wall. These information can be crucial for GPF wall substrate design and washcoating
Yang, Pengze, Cheng, Zhen
High Performance DPF to Tackle Nano Particulate Emissions for Off-Highway Applications2025-01-850104/01/2025
Diesel Particulate Filters (DPFs) have been used extensively worldwide as a Particle Mass (PM) / Particle Number (PN) reduction technology for various diesel applications. Based on CARB’s latest Tier 5 regulation workshop, PM emission targets are expected to become a lot more stringent; from 0.02 g/kWh to 0.005 g/kWh (75% reduction compared to Tier 4 Final (Tier 4f)). Also, CO2 emission targets are expected to be introduced for Tier 5. In parallel, EU Stage VI emission regulation standards and implementation timing could be announced sometime in late 2024. It is expected that PN emission standards will be tightened such as extending measurement range of PN from 23 nm to 10 nm. With Tier 5 and EU Stage VI regulations approaching, several OEMs are considering implementing a common aftertreatment system that can meet emission targets for both regions. High filtration efficiency and low backpressure DPFs will be required to meet PM/PN and CO2 emission standards. NGK has developed several
Fakih, Hussein, Elizondo, Zachery, Ishikawa, Hiroaki, Yoshioka, Fumihiko, Kato, Kyohei, Suzuki, Hiroaki, Aoki, Takashi, Ito, Yoshitaka
Characterization of Dimethyl Ether (DME) Spray Using ECN Spray D Under Engine-Relevant Conditions2025-01-845704/01/2025
This research experimentally investigates the spray vaporization of high-pressure dimethyl ether (DME) using a single-hole research injector focusing on nominal operating conditions from the Engine Combustion Network (ECN). DME is a synthetic alternative to diesel fuel, offering both high reactivity and potential reductions in particulate emissions. Because DME only features half of the energy density of diesel fuel, a specifically designed fuel system with a high mass flow rate to meet the energy delivery requirements is needed. The unique physical properties of DME, including higher vapor pressure and lower viscosity, introduce challenges like cavitation and unique evaporation characteristics that deviate from typical diesel fuel. These features are likely to lead to differences in fuel mixing and combustion. This study aims to provide detailed experimental data on DME spray characteristics under engine-like conditions, helping the development of predictive CFD models for optimal
Yi, Junghwa, Wan, Kevin, Pickett, Lyle, Manin, Julien
Effect of Fuels on Compression Ignition Engine Particle Number and Mass Emissions and DPF Filtration Efficiency2025-01-850204/01/2025
As part of decarbonization, alternative fuels are likely to be used in compression ignition internal combustion engines as a substitute for diesel fuel. There have been many studies on the effect of these alternative fuels on emissions and catalytic aftertreatment systems. Past research has reported lower particulate matter (PM) and higher oxides of nitrogen (NOx) with biofuels. However, there are limited studies on the effect of PM on the performance of diesel particulate filters (DPFs), especially in its effectiveness of PM filtration. PM emissions from four (4) types of fuels and five (5) of their blends, a total of nine fuels, were investigated using PM2.5 mass, soot mass, solid particle number (> 10 nm SPN10 and > 23 nm SPN23) and size distribution (6 nm to 560 nm) measurements at inlet and outlet of a DPF. The PM emissions were measured over a non-road regulatory cycle sequence consisting of five (5) non-road transient cycles (NRTCs) and five (5) non-road steady-state cycles
Lakkireddy, Venkata, Khalek, Imad, Buffaloe, Gina
Sensor Cluster for Recording the Spread of Emissions in the Wake of a Vehicle2025-01-849204/01/2025
Progressive emission reductions and stricter legislation require a closer look at the emission behaviour of a vehicle, in particular non-exhaust emissions and resuspension. In addition to the analysis of emissions in isolation, it is also necessary to consider the impact of transport routes and dispersion potential. These factors provide insight into the movement of dust particles and, consequently, the identification of particularly vulnerable areas. Measurements using low-cost environmental sensors can increase the level of detail of dispersion analyses and allow a statement on the distribution of emissions in the vehicle's wake, as several measuring points can be covered simultaneously. A newly developed measurement setup allows vehicle emissions to be recorded in a plane behind the vehicle in a measurement area of 2 by 2 metres. The measuring grid consisting of 16 sensors (4x4 grid) can be variably positioned up to 1 metre from the rear of the vehicle. The sensors detect fine dust
Kunze, Miles, Ivanov, Valentin, Gramstat, Sebastian
Correlation of Total Aromatics and Speciated Aromatic Analysis by ASTM D5769 (Determination of Aromatics) and ASTM D6730 (Detailed Hydrocarbon Analysis) of US Market Gasoline Samples2025-01-845304/01/2025
The Standard Test Method for Determination of Benzene, Toluene, and Total Aromatics in Finished Gasolines by Gas Chromatography/Mass Spectrometry, also known as ASTM D5769, identifies aromatic compounds ranging from carbon groups six to twelve (C6-C12). This method provides determination in less than 15 minutes of twenty-three target aromatics, quantification of uncalibrated Indans, as well as C10, C11, and C12 aromatics using extracted ions. In contrast, the Standard Test Method for Determination of Individual Components in Spark Ignition Engine Fuels by 100-MetreCapillary (with Precolumn) High-Resolution Gas Chromatography (ASTM D6730) offers a more comprehensive identification of compounds of multiple classes in gasoline samples also using a mass spectrometer (MS), focusing on aromatics from C6 to C14 for this research. This method uses a standard template of identified fuel components and corrects responses based on theoretical Flame Ionized Detector (FID) hydrocarbon responses
Dozier, Jonathan, Goralski, Sarah, Geng, Pat, Reilly, Veronica
Transforming Respiratory Imaging: Mapping Airway Cilia in Real TimeTBMG-5285104/01/2025
Cilia, small, slender, hair-like structures present on the surface of all mammalian cells, play a major role in locomotion and are involved in mechanoreception. Ciliary motion in the upper airway is the primary mechanism by which the body transports foreign particulates out of the respiratory system to maintain proper respiratory function.
Study on the Impact of Arrangement of Urea Injector and Mixer in Diesel Engine Selective Catalytic Reduction System on Ammonia Uniformity02-18-02-000702/12/2025
With the continuous upgrading of emission regulations for internal combustion engines, the nitrogen oxide treatment capacity of selective catalytic reduction (SCR) aftertreatment needs to be continuously improved. In this study, based on a prototype of SCR aftertreatment, the impact of the arrangement of key components in the SCR system (urea injector, mixer, and catalyst unit) on ammonia uniformity was investigated. First, parameterized designs of the urea injector, mixer, and SCR unit were conducted. Then, using computational fluid dynamics (CFD), numerical simulations of the established aftertreatment system models with different parameter factors were performed under a high-exhaust temperature and a low-exhaust temperature conditions to study the impact of each individual parameter on ammonia uniformity. Finally, an optimized solution was designed based on the observed patterns, and the optimized samples were tested on an engine performance and emission test bench to compare their
Jie, Wang, Jin, Jianjiao, Wu, Yifan
Experimental Evaluation of Binary Iso-Dodecane/n-Dodecane Blends for Emulating Sooting Characteristics of Sustainable Aviation Fuels01-18-01-000302/06/2025
Sustainable aviation fuels (SAFs) derived from renewable sources are promising solutions for achieving carbon neutrality and further controlling aircraft engine emissions, operating costs, and energy security. These SAFs, primarily consist of branched and normal paraffins and exhibit significantly reduced sooting tendencies compared to conventional petroleum-based jet fuels, due to their lack of aromatics content. Our previous study investigated soot formation in non-premixed combustion for three ASTM-approved alternative jet fuels, namely Fischer–Tropsch synthetic paraffinic kerosene (FT-SPK), hydroprocessed esters and fatty acids from camelina (HEFA-Camelina), and alcohol-to-jet (ATJ), and demonstrated that the varying paraffinic composition within SAFs results in diverse sooting propensities, in the order of ATJ > FT-SPK > HEFA-Camelina. To evaluate the impact of iso-paraffins on sooting tendency and validate the suitability of utilizing binary blends of iso-dodecane (iC12) and
Xue, Xin, Sung, Chih-Jen, Wang, Xiaofeng
Flash Boiling Impact on Spray, Flame, Emissions, and Soot of Gasoline-Acetone-Butanol-Ethanol Blend at Simulated Cold-Start GDI Operation Using a CVCC2025-01-704601/31/2025
The use of carbon-neutral fuels instead of conventional fuels in gasoline direct injection (GDI) engines is beneficial to global decarbonization. However, the application of renewable non-petroleum fuels in GDI engines is still unclear due to their different physicochemical properties. Acetone-Butanol-Ethanol (ABE) is a promising low-carbon alternative fuel for GDI engines, but its high viscosity and latent heat cause pool firing during cold start. The existing flash boiling technology can solve this problem. This study explores the effects of flash boiling on spray characteristics, flame propagation, soot, and emissions of gasoline-ABE blend in a constant volume combustion chamber (CVCC) without airflow. Optical windows, high-speed camera recording, in-chamber pressure measurement, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscope (TEM) were used to analyze flame spreading, combustion characteristics, exhaust gases, and soot morphology. Flash boiling
Nour, Mohamed, Zhang, Weixuan, Cui, Mingli, Li, Xuesong, Xu, Min, Qiu, Shuyi
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