Browse Topic: Environment

Items (41,728)

Modeling fuel consumption in a heavy-duty diesel truck under real-world driving conditions including cold-start operation

2025-24-0096To be published on 09/07/2025

Heavy-duty vehicles contribute significantly to global greenhouse gas emissions and are now facing challenges in meeting emission regulatory standards, with particular reference to cold-start operations. Advanced powertrains that make use of hybridization and waste heat recovery with phase-changing materials offer potential pathways to mitigate fuel consumption and emissions under real-world driving conditions. Still, they need to be accurately sized and managed to overcome the disadvantages of increased mass and complexity. This investigation paves the way for developing such advanced power systems by implementing a scalable map-based model for heavy-duty diesel engines. The model is validated using an open access data set related to a heavy-duty vehicle equipped with a 6-7L diesel engine performing 28 different trips on the same route with the same driver. The trips are performed with three different values of payload and contain both cold-start and hot-start operating conditions

Donateo, Teresa, Mujahid, Talha, Morrone, Pietropaolo, Algieri, Angelo

Experimental Assessment of ‘Drop-in’ and ‘Optimized’ HVO usage in a 6.6l Diesel Engine for Low-emissions Marine Applications

2025-24-0073To be published on 09/07/2025

All mobility sectors are facing the challenge to contribute actively to the reduction of environmental pollution and of the impact on climate change driven by Greenhouse Gas effect. One of the most active sectors in the research of environment-friendly propulsion propositions is the recreational and light-commercial boating. Presently, many of the boats operating in this sector are propelled by internal combustion engines derived from road applications. In this work, the effects of replacing conventional fossil-derived B7 diesel with Hydrotreated Vegetable Oil (HVO) were experimentally investigated in a modern Medium-Duty Engine, using the advanced biofuel initially as drop-in replacement, and then repeating the testing after the recalibration of the engine combustion setpoints. Comparing the results of the replacement of diesel with HVO showed appreciable benefits in terms of NOx, Particulate Matter (PM), mass fuel consumption and Well-to-Wake (WtW) CO2 thanks to the inner properties

Cosseddu, Cinzia, Spedicato, Tonio, Pennazio, Davide, Vassallo, Alberto, Fittavolini, Corrado

Mid-IR Laser Extinction Measurement of Formaldehyde Emissions in a Methanol Mixing-Controlled Compression Ignition Engine

2025-24-0034To be published on 09/07/2025

As the energy security and sustainability becomes important and restrictions on carbon footprints grow stricter, the role of low-carbon alternative fuels, particularly methanol, is becoming increasingly significant. While the feasibility of methanol as a substitute for diesel fuel has been explored, understanding of emissions from methanol-fueled compression-ignition engines remains limited, even though these engines are known to emit formaldehyde (CH2O) due to methanol’s chemical structure and oxidation pathways. In this study, a quantitatively measurable mid-IR laser-based extinction methodology was employed to understand CH2O formation in a methanol mixing-controlled compression ignition engine. Stable methanol compression ignition combustion was achieved with the addition of 5%vol 2-ethylhexly nitrate and by using a triple injection strategy (pilot + pilot + main), and CH2O emissions were measured with high temporal resolution by laser extinction while sweeping the injection timing

Lee, Sanguk, Lopez Pintor, Dario, Narayanan, Abhinandhan

Combined Virtual and Experimental Approach to Develop Highly Efficient Metallic Catalyst for New World Wide Emission Legislation

2025-24-0080To be published on 09/07/2025

The market penetration of Battery Electric Vehicles (BEV) in Europe is not following the foreseen scenario. This is related to several factors, such as uncertainty of the second-hand value of BEV, real driving range under cold conditions and availability of charging stations. Even if the European Community is still planning a full ban of Internal Combustion Engines (ICE) by 2035. In the rest of the world a more technology neutral approach is being pursued with car manufacturers developing different powertrain architectures, from mild- to full-hybrid and Range Extenders (REEX). In this context the different emission regulations, and the wide range of powertrain architectures, the focus of the development will be the increase of catalyst efficiency without any big impact on exhaust aftertreatment cost. In this work the authors have used a 1D simulation approach to support the optimization of metallic TWC substrate for the High Power Cold Start use case. Additionally, a 3D CFD was used

Montenegro, Gianluca, Della Torre, Augusto, Marinoni, Andrea, Onorati, Angelo, Klövmark, Henrik, Laurell, Mats, Pace, Lorenzo, Konieczny, Katrin

Enabling near-zero emissions and superior efficiency in large-bore, medium-speed engines with a hydrogen-argon power cycle

2025-24-0001To be published on 09/07/2025

Combustion engines operating on a hydrogen-argon power cycle (H-APC) offer potential for superior thermal efficiency with true zero exhaust emissions. The high specific heat ratio of argon allows extrapolation of the theoretical efficiency of the Otto cycle to almost 90%. However, this potential is significantly constrained by challenges in combustion control, excessive thermal loading, and system integration, particularly regarding argon recovery. This study investigates these trade-offs, within the context of real-world engine-based peaking power plants. An experimentally validated 1D-simulation model of a prototype Wärtsilä 20 DF engine serves as reference for analysis of a retrofit incorporating a closed-loop argon cycle, with dedicated H₂ and O2 injectors, a water condenser and water separator. Engine performance is evaluated at reference operating point of 75% load, considering pre-ignition, peak pressure and exhaust temperature constraints, condenser limitations, and impurity

Ahammed, Sajid, Ahmad, Zeeshan, Mahmoudzadeh Andwari, Amin, Kakoee, Alireza, Hyvonen, Jari, Mikulski, Maciej

Influence of the SCR reactivity on passive soot oxidation for vanadium-coated and uncoated (S)DPF

2025-24-0086To be published on 09/07/2025

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

S.I.S.T.E.R.: an integrated approach to non-exhaust emissions

2025-24-0091To be published on 09/07/2025

As electric mobility spreads and evolves, non-exhaust Particulate Matter 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 needed to develop a new platform capable of both creating testing methodologies for future regulations and enabling the parallel development of advanced tires and brakes that meet these standards, by correlating vehicle dynamics, driving style, tire 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 tire/brake-related emissions from the initial stages of compound development to outdoor vehicle tests, allowing actions to be taken

Genovese, Andrea, De Robbio, Roberta, Lenzi, Emanuele, Caiazza, Antonio, Lippiello, Felice, Costagliola, Maria Antonietta, Marchitto, Luca, Serra, Antonio, Arimondi, Marco, Bardini, Perla

Numerical Investigation of Lean Neat Ammonia Combustion in a Heavy-Duty Diesel Engine Converted to Spark Ignition

2025-24-0032To be published on 09/07/2025

Ammonia (NH3) use as fuel poses technical challenges such as increased nitrogen-based and unburned NH3 emissions. This study used a 0D model coupled with detailed NH3 kinetics to evaluate the effect of equivalence ratio (ϕ) from 0.7 to 1.0 in a heavy-duty compression ignition engine converted to spark ignition operation. The goal was to evaluate how ϕ affected NOx and N2O formation and/or destruction at constant fuel energy per cycle, engine speed, and CA50. Simulated NOx emissions (i.e., NO + NO2) followed a trend similar to the one typically observed for hydrocarbon fuels in a SI engine, but that was different from the experiment. In addition, it underpredicted NOx emissions for ϕ = 0.7 by 79% and overpredicted NOx emissions for ϕ = 1 by 576%. The simulation showed that thermal NO production was more than 80% from the total NO production, but the effect of ϕ on this percentage was negligible. Then, predicted N2O emissions had an opposite trend and were three orders of magnitude lower

Saenz Prado, Stefany, Alvarez, Luis F., Trujillo Grisales, Juan M., Akkerman, Vyacheslav, Dumitrescu, Cosmin E.

Optical diagnostic analysis of methane combustion performance and emissions while incorporating ammonia and multiple flames in a spark-ignition engine

2025-24-0023To be published on 09/07/2025

The current state of internal combustion engine technology necessitates the use of cleaner fuels with lower carbon content in order to mitigate CO2 release into the atmosphere. Ammonia and methane show potential as alternatives to traditional hydrocarbon fuels due to their ability to reduce carbon emissions. This study investigated the use of different energy fractions of ammonia in a methane mixture to reduce carbon-based emissions. However, ammonia, being a less reactive fuel with a lower flame speed than methane, may negatively impact engine performance. To address this, the study employed a multiple flame generation approach to accelerate the combustion rate. The experiment was carried out on a single-cylinder four-stroke optical research engine. To initiate multiple flame fronts, a customized metal liner with four equi-spaced spark plugs was utilized. To compare the results with conventional spark-ignition conditions, one spark plug was placed at the center of the cylinder head

Uddeen, Kalim, Tang, Qinglong, Shi, Hao, Turner, James

Integrated CFD-Experimental Methodology for Hydrogen-Fuelled Small Loop Scavenged Two-Stroke Engines

2025-24-0014To be published on 09/07/2025

This paper presents an integrated methodology for the analysis of hydrogen-fuelled two-stroke engines, combining experimental data, 1D CFD simulations, and 3D CFD combustion calculations. The proposed approach aims to enhance the understanding of scavenging, injection, and combustion processes in a 50 cc loop-scavenged engine with low-pressure direct hydrogen injection (LPDI), experimentally studied on a test bench. The performance of the hydrogen-fuelled engine was slightly lower compared to gasoline operation, achieving a maximum power output of 3.1 kW compared to 3.6 kW with gasoline, using a slightly lean air-fuel ratio (lambda = 1.3). The maximum engine speed for stable combustion without knocking was achieved at wide-open throttle (WOT) at 7000 RPM. The developed 1D CFD model, based on the layout at the test bench, was calibrated using average experimental data and specific full-load operating points. 3D CFD simulations were performed for two full-load operating points, focusing

Caprioli, Stefano, Ferretti, Luca, Scrignoli, Francesco, Fiaschi, Matteo, D'Elia, Matteo, Oswald, Roland, Schoegl, Oliver, Nambully, Suresh Kumar, Rothbauer, Rainer, Mattarelli, Enrico, Kirchberger, Roland, Rinaldini, Carlo

Toward sustainable Heavy-Duty transport: evaluating charge dilution and Advanced Corona Ignition System effects on SI natural gas engine efficiency and combustion characteristics

2025-24-0024To be published on 09/07/2025

Reducing greenhouse gas (GHG) emissions in the transportation sector is a significant challenge. A multi-technology approach is the most practical and sustainable solution for minimizing the environmental impact of road transport. Alternative gaseous fuels derivable from bio sources have the potential to significantly cut CO2eq emissions from a Well-to-Wheel perspective, and the development of technologies that allow to improve the efficiency of natural gas-powered Heavy Duty (HD) Spark Ignition (SI) engines is of strategic importance. In such applications, charge dilution strategies might have the potential to increase engine efficiency at a relatively low implementation cost. Diluting the in-cylinder charge can reduce fuel consumption by decreasing wall and pumping losses, and increasing the Heat Capacity Ratio. The coupling with innovative technologies aimed at enhancing ignition energy, influencing combustion development, could be a promising scientific path for achieving more

Di Domenico, Davide, Napolitano, Pierpaolo, Papi, Stefano, Ricci, Federico, Golini, Stefano, Rapetto, Nicola, Giordana, Sergio, Beatrice, CARLO

Towards Effective SCR System Optimization: A 3D-CFD and Experimental Study Enabling Faster Deposit Formation Risk Assessment

2025-24-0087To be published on 09/07/2025

Selective Catalytic Reduction (SCR) is a key technology for reducing nitrogen oxides (NOx) emissions in diesel engines. In this process, a urea-water solution (UWS) is injected upstream of the catalyst to generate ammonia, which reacts with NOx to form nitrogen. However, liquid urea can adhere to system walls, undergoing secondary reactions that lead to the formation of solid deposits. These deposits must be minimized to ensure the long-term durability and efficiency of the system. Computer-Aided Engineering (CAE) simulations play a crucial role in optimizing SCR performance during the design phase. However, accurately predicting deposit formation requires detailed chemical modelling, which is computationally expensive and introduces uncertainties related to reaction mechanisms definition. To address this challenge, simplified CAE approaches are needed to assess deposit formation risks while maintaining computational efficiency. This study presents an improved Deposit Risk Index (DRI

Bianco, Andrea, Prestifilippo, Mattia, Robino, Cristina, Petrafesa, Giovanni, Postrioti, Lucio, Buitoni, Giacomo

Development of a compact hydrogen engine for commercial applications

2025-24-0060To be published on 09/07/2025

As the individual and commercial vehicle industries seek sustainable alternatives to conventional internal combustion engines, hydrogen-fueled rotary engines are emerging as a promising solution for several applications. This paper presents an innovative approach for the development of a hydrogen rotary engine that is integrated within a hybrid system. By exploiting the unique characteristics of rotary engines, such as compact size and high power-to-weight ratio, the electric machine, the battery and the rotary engine can be accommodated in the installation space of a conventional ICE with comparable power, despite the reduced power density of hydrogen as a fuel in internal combustion engines. In this way, the proposed system aims to avoid CO2 emissions and improve the overall performance of the powertrain. As a first step, the hydrogen engine is naturally aspirated and equipped with direct injection. To develop a suitable calibration for the engine’s application, the influence of

Endres, Jonas, Beidl, Christian, Hofmann, Silas

Numerical Investigation on an Injection Strategy Optimization for Dual Fuel Marine Engine Fuelled by Ammonia

2025-24-0013To be published on 09/07/2025

In the context of greenhouse gas reduction (GHG) the most viable short-term solution in the maritime sector is the use of renewable carbon-free fuels. Among these, ammonia represents a possible alternative in compression ignition (CI) engines operating in dual fuel (DF) mode. Although, such fuel features low chemical reactivity, especially in lean mixtures, resulting in poor combustion efficiency, exhaust ammonia slip and low engine performance, DF combustion can be an interesting strategy to overcome such combustion limitations. In this work a wide examination of diesel injection strategies is numerically presented, while ammonia acts as the primary fuel with energy shares around 80%. Since the original marine engine, fuelled with natural gas (NG), presents a single diesel injection, firstly, a pilot injection is added and different diesel mass distributions between pilot and main are investigated, by varying the injection rate shape and the pilot start of injection (SOI

Cameretti, Maria Cristina, De Robbio, Roberta, Palomba, Marco

Neural-Based Real-Time Driving Suggestions System for Components Preservation in Battery Electric Vehicles Using Model-Based Datasets

2025-24-0115To be published on 09/07/2025

Nowadays, Battery Electric Vehicles (BEVs) are considered an attractive solution to support the transition towards more sustainable transportation systems. Although their well-known advantages in terms of overall propulsion efficiency and exhaust emissions, the diffusion of BEVs on the market is still reduced by some technical bottlenecks. Among those, the uncertainty about the expected durability of the vehicle on-board battery packs plays a key role in affecting customer choice. In this context, this paper proposes the use of model-based datasets for training a driving support system based on machine learning techniques to be installed on board. The objective of this system is to acquire vehicle, environmental, and traffic information from sensors’ networks and provide real-time smart suggestions to the driver to preserve the remaining useful life of vehicle components, with particular reference to the battery pack and brakes. For the generation of the training dataset, first, a set

Bernardi, Mario Luca, Capasso, Clemente, Iannucci, Luigi, Sequino, Luigi

Development of a cloud based operating strategy for an electrified trailer system

2025-24-0117To be published on 09/07/2025

The need for greenhouse gas emission reductions leads to decreasing emission limits in road traffic. The development of efficient powertrains and the use of renewable energy sources are crucial in order to meet these targets. Electrification is one of the key technologies that can help to achieve higher efficiency and lower emissions. Besides the passenger car segment, electrification has started to play a more important role in heavy-duty applications as well. One technology that has been discussed in the last years is the electrification of heavy-duty semi-trailers. In the joint research project "evTrailer2" funded by the German Federal Ministry for Economic Affairs and Climate Action, the potential of different technologies for electrified semi-trailer systems in long-haul applications is evaluated. The overall project goal is the development of high efficiency technologies to help reduce the fuel consumption and therefore the greenhouse gas impact of large semi-trailer trucks. The

Knaup, Lars, Beidl, Christian

Multilevel control strategy design and optimization for fuel cell hybrid heavy-duty vehicles

2025-24-0107To be published on 09/07/2025

The heavy-duty transportation sector is a major contributor to greenhouse gas emissions, highlighting the urgent need for zero-emission solutions. This research aims to develop a multilevel control architecture that optimizes fuel economy and minimizes emissions in fuel cell hybrid heavy-duty vehicles (FCH2DV), equipped with proton exchange membrane fuel cell and battery pack as the main power sources. The detailed fuel cell system model incorporates mass and thermal dynamics, including air supply, hydrogen flow, water management and their effects on reaction kinetics, membrane conductivity, water balance, performance and durability. The low-level control strategy is designed using a physics-based approach that accounts for critical constraints, including temperature, relative humidity and differential pressure between the cathode and anode. By identifying the optimal setpoints for key control variables, this methodology enables the development of accurate control maps for actuator

Bove, Giovanni, Aliberti, Paolo, Simone, Christian, Sorrentino, Marco, Pianese, Cesare

Τesting and modeling of a passive SCR system for hydrogen engines

2025-24-0082To be published on 09/07/2025

Heavy-duty vehicles powered by hydrogen internal combustion engines (H2 ICEs) present a compelling solution for sustainable transportation.. When optimized for ultra-lean operation, H2 ICEs are capable of meeting the most stringent contemporary legislative emission standards. However, achieving optimal drivability necessitates occasional to an enriched operating mode, thereby presenting significant challenges in maintaining ultra-low emissions. In this context, the implementation of advanced exhaust after-treatment technologies becomes essential to ensure near-zero tailpipe emissions with minimal impact on fuel efficiency and drivability. This paper investigates the potential of a passive Selective Catalytic Reduction (SCR) exhaust configuration for a heavy-duty hydrogen (HD H₂) engine, employing testing and modeling of a Lean NOx Trap, utilized as an ammonia (NH₃) generator, in conjunction with a downstream Selective Catalytic Reduction system. We underscore the complexities

Zafeiridis, Menelaos, Alexiadou, Panagiota, Koltsakis, Grigorios

Analysis of combustion characteristics and performance of a multi-cylinder Dual-fuel HCCI engine.

2025-24-0042To be published on 09/07/2025

Despite significant advancements in internal combustion engine efficiency, fossil fuels still hinder progress toward sustainable energy. Syngas, a gasification byproduct of hydrogen and carbon monoxide, is a promising transitional fuel due to its compatibility with existing combustion technologies, improved efficiency, and lower emissions. It is well-suited for HCCI engines, known for high thermal efficiency and reduced NOₓ and particulate emissions. However, Syngas combustion requires elevated intake temperatures or admission pressures to ensure optimal thermodynamic conditions. To overcome this, a small quantity of diesel enhances ignition stability and extends the engine’s operational range in dual-fuel combustion. While most previous experimental studies have focused on syngas-diesel dual-fuel operation in single-cylinder setups, this research expands the analysis to a multi-cylinder engine. It accounts for cylinder-to-cylinder variations, chemical interactions, and thermal

EL YOUNSI, Laila, Nelson-Gruel, Dominique

Vehicle Under-Hood Thermal Management: Development of a Reduced-Order Model for Accurate and Computationally Efficient Temperature Distribution Simulations

2025-24-0118To be published on 09/07/2025

Electrified vehicle energy management plays a crucial role in the context of the European Green Deal by facilitating the transition toward sustainable mobility. The development of predictive and robust simulation tools is essential to implement and test different energy management strategies. This study aligns with this objective by presenting the development of an under-hood flows model designed for integration into a 1D vehicle simulator, which is used to perform vehicle simulations about longitudinal performances, energy consumption and range. Vehicle under-hood thermal management is inherently complex due to the interplay of internal flow dynamics and multiple heat transfer mechanisms. A purely 1D modeling approach lacks the spatial resolution required to capture detailed flow field characteristics, while a fully 3D CFD model is computationally prohibitive for scenarios requiring efficient simulations. To address this trade-off, a reduced-order model (ROM) approach is proposed. The

Miccio, Stefano, Grattarola, Federico, Baratta, Mirko, Giraudo, Gabriele, Frezza, Davide, Bartolucci, Lorenzo

Development of an Euro VII Compliant Diesel Combustion System for Light Commercial Vehicles

2025-24-0035To be published on 09/07/2025

Recent European regulations introduced in the transportation sector have increased stringency on tailpipe CO2 and regulated emissions, starting 2025. The development of advanced engine technologies and the utilization of alternative fuels for internal combustion engines plays a key role in the short- to mid- term in complying with such regulations and supporting sustainable transition. In this study, the focus has been to develop an advanced Diesel combustion system for light commercial vehicles application in compliance with the latest Euro VII regulations and with the primary aim to improve fuel economy. The adopted methodology considered a coupled 1D-3D CFD virtual development and optimization of the entire combustion system encompassing bowl shapes, injector nozzles, and intake port specifications. Two advanced combustion system ‘recipes’ have been identified and then experimentally investigated to fine-tune the nozzle specifications, injection strategies and charge motion by means

Belgiorno, Giacomo, Malagrinò, Gianfranco, Pezza, Vincenzo, Spedicato, Tonio, Storsillo, Vito, Gallone, Alessandro, Alletto, Massimiliano, Pesce, Francesco, Vassallo, Alberto, Colombo, Giovanni, Formica, Angelo, Lerda, Francesco, Mirzaeian, Mohsen, Vitiello, Michele

Water injection as an enabling technology for stoichiometric high performance normally aspirated engines

2025-24-0027To be published on 09/07/2025

The mainstream automotive market is rapidly transitioning to electrified and fully electric powertrains. Where gasoline engines are still employed, they are frequently turbocharged units with relatively low maximum engine speed and modest power density. The hypercar class, in contrast, has recently seen somewhat of a renaissance in high performance, high speed naturally aspirated gasoline engines, which are prized for their emotional contribution to the vehicle. In order to guarantee high conversion efficiency of a Three Way Catalyst in the exhaust system, an engine must be operated at stoichiometric air-fuel ratio. At high power density, this may result in very high exhaust gas temperature, which poses a risk to engine and vehicle hardware. A number of technological interventions to extend the maximum stoichiometric performance whilst respecting component limitations have already been described in the literature, but many of these are not applicable to specific engine architectures in

Corrigan, Dáire James, Villa, Davide, Penazzi, Eugenio, Meghani, Amit, Knop, Vincent, Caroli, Giacomo, Frigeri, Davide, Ruggiero, Federico, Malaguti, Simone, Postrioti, Lucio, Maka, Cristian

Model-based optimization of Diesel/OMEx fuelled CI engine under multiple blending conditions

2025-24-0038To be published on 09/07/2025

The search for alternative solutions for vehicle electrification, while reducing the carbon footprint during the transition towards green mobility, leads to the investigation of electro-fuels (e-fuels) in conventional internal combustion engines. Leveraging previous research, the present study focuses on the optimisation of CI engine combustion control in response to the use of the Oxymethylene Ethers (OMEx) blended with conventional diesel fuel. The selected e-fuel is the OME3, which is expected to be used as a drop-in solution and to easily achieve a reduction in soot emissions due to both its high oxygen content and lack of direct carbon bonds in its molecular structure. To verify its potential, a 1D single-cylinder CI multi-zone engine model has been exploited to simulate various diesel/OME3 blends in a wide engine operating range. The first step deals with the evaluation of performance and emissions to demonstrate the differences, particularly in terms of emissions reduction

Foglia, Antonio, CERVONE, Davide, Frasci, Emmanuele, Arsie, Ivan, Polverino, Pierpaolo, Pianese, Cesare

The Potential of Varying the Air/Fuel Ratio at different EGR-Rates on a Medium-Speed Dual-Fuel Marine Engine

2025-24-0041To be published on 09/07/2025

The dual-fuel combustion process, which is offered as a retrofit solution for conventional diesel engines by various manufacturers, represents an option for reducing emissions from internal combustion engines and is already available today. Current dual-fuel engines run on liquefied natural gas (LNG), which is usually of fossil origin. Thanks to the existing infrastructure and the possibility of producing LNG by means of electrolysis and methanation, LNG can already be produced in a 100 % climate-neutral way and thus make a contribution to climate neutrality in the shipping industry. The adoption of Exhaust Gas Recirculation (EGR) systems in the maritime sector became more significant in 2020 following the enforcement of the sulphur emission cap. By lowering the sulphur content in the fuel, technologies in the exhaust tract are also conceivable without the use of expensive scrubber systems. The use of an EGR system can reduce nitrogen oxide emissions in engines. Dual-fuel engines are

Seipel, Pascal, Glauner, Manuel, Dinwoodie, Jules, Buchholz, Bert

Methodology for the Study of Hydrogen Combustion in an Optical Spark Ignition Engine.

2025-24-0062To be published on 09/07/2025

The use of hydrogen as a fuel in internal combustion engines represents a promising alternative for reducing CO2 emissions. To optimize its efficiency and better understand the phenomena associated with its combustion, it is essential to have advanced visualization techniques for a better understanding of the processes involved. This paper presents the methodology used in the development of an optical engine for the study of hydrogen combustion, designed from a 454cc single-cylinder engine. The configuration of the optical system is described, which includes the use of high-speed cameras to capture the spark plug activation as well as the flame propagation in the combustion chamber. The engine has two optical accesses, one through the piston and one at the top of the cylinder that allows side viewing of the combustion chamber. In addition, the experimental procedure that alternates combustion cycles with motoring cycles, the determination of the air-hydrogen ratio with which the engine

Pastor, Jose V., Novella, Ricardo, Tejada, Francisco J., Cáceres-Carías, José

Experimental Investigation of Usage Limits of Various Alcohol-Based Fuels in Spark Ignition Engine

2025-24-0031To be published on 09/07/2025

Current ambitious targets of transport utilized fossil fuels replacement pose a considerable challenge while transportation affordability, energetic and precious materials security are to be maintained. Most of current solutions oriented to passenger cars fossil fuel replacement by more renewable resources are dependent on one method only. On other hand, each of them exhibits some drawbacks and benefits while a reasonable combination could mitigate number of limitations and include many of advantages. Such solution could be usage of wide range liquid fuels from renewable resources in a suitable spark ignition engine accompanied by common battery electricity storage. The aim of this experimental work was to develop and demonstrate possibilities and results of an uncomplex engine adaptation to a wide range of fuels obtainable from renewable resources suitable as a range extender to commonly proposed electric cars. The approach chosen used standard gasoline as a starting fuel followed by

Pechout, Martin

A New Methodology to Evaluate In-Service Emissions of Used Vehicles at a Large Scale using a SEMS and Digital Tools

2025-24-0090To be published on 09/07/2025

Air quality is an increasing concern, particularly in densely populated urban areas. Indeed, large European cities have seen pollutant concentrations exceed World Health Organization thresholds, with a significant portion of NOx emissions originating from road transportation. Studies have shown that less than five percent of the vehicle fleet, often including vehicles with defective after-treatment systems, is responsible for a disproportionate share of these emissions. This highlights the importance of not solely relying on the gradual renewal of vehicle fleets to mitigate health risks associated with air pollution. This research, funded by the French Agency for the Ecological Transition (ADEME), introduces an experimental methodology aimed at controlling emissions from vehicles already in circulation. Aramis Group, a European specialist of refurbishment and online sales of used cars, provided several refurbished used vehicles for testing, directly taken from its workflow. These

Carlos Da Silva, Daniel, KERMANI, Joseph, Farcot, Fabrice, Gaie, Fabien

Data-driven modeling of H2-SCR catalysts for real-time estimation of NOx reduction efficiency

2025-24-0084To be published on 09/07/2025

Achieving zero emissions across transportation is a tremendous challenge. The upcoming Euro 7/VII standards, set to be enforced in 2025, will mandate further reduction in ICEs exhaust emissions. Thus, additional improvements and potential new technologies are needed to bring ultra-low emissions vehicles. Hybrid propulsion powertrains and alternative fueled (syn-fuels, e-fuels, etc.) engines represent bridging technologies for reducing harmful gas emissions (GHG, NOx, PM, etc.) in the medium term, overcoming the main drawbacks of the pure electrified powertrain (BEV, FCEV), especially for heavy-duty vehicles. Hydrogen seems to be a very attractive fuel, thanks to its high lower heating value, clean combustion, and extremely low pollutant emissions, due to the zero-carbon content. Nevertheless, NOx emissions are still an issue in hydrogen fueled engines and optimized lean-burn combustion and suitable after-treatment NOx reduction are mandatory to reach high specific power and efficiency

Crispi, Maria Rosaria, Conde Cortabitarte, Carla, Occhicone, Alessio, Piqueras, Pedro, Arsie, Ivan, Pianese, Cesare

DLR Tire Road Wear Particle Emission Testing Methodology – Collection System Influence and Repeatability Assessments

2025-24-0092To be published on 09/07/2025

Tire road wear particle (TRWP) emissions are a significant contributor to airborne particulate matter (PM), with increasing concerns regarding their environmental and health impacts. However, the lack of standardized methodologies for TRWP measurements interferes with comparability across studies and limits emission factor assessment. This study systematically evaluates the influence of the collection system design on TRWP measurement outcomes and assesses the repeatability of a novel housing-based collection system in a controlled dyno chassis test bench environment. In the first part of the study, a three-step methodology—generation, collection, and analysis—was applied under controlled boundary conditions to compare two distinct collection systems. The housing-based system encloses the tire while also separately encapsulating the brake system, preventing brake wear particles from mixing with TRWP. In contrast, the nozzle-based system has no encapsulation for either the tire or the

Celenlioglu, Melis Seren, Epple, Fabius, Reijrink, Nina, Löber, Manuel, Reiland, Sven, Vecchi, Roberta, Philipps, Franz

Understanding and Qualifying Hydrogen combustion related phenomena for Low-Carbon Mobility

2025-24-0057To be published on 09/07/2025

The reduction of the overall greenhouse gas and pollutant emissions from ground vehicles is mandatory to fight against global warming and health issues. Moreover, regarding the increasing demand related to the population growth, the energy requirement for mobility may significantly increase during coming years. Meeting greenhouse gas emission targets is not only about commitment to regulations but also fundamentally about enhancing human well-being. Consequently, the diversification of low-carbon energy sources is of huge interest. The use of Hydrogen (H2) as a sustainable energy source in ground transportation is an alternative or a complementary solution to the full electric vehicles. Hydrogen for mobility can be used in two types of energy converters: The Proton-Exchange Membrane Fuel Cell or the H2 adapted Internal Combustion Engine (H2-ICE). This last has the advantage of its strong maturity with the reuse of existing production infrastructures from conventional ICE and low raw

Laget, Olivier, Bardi, Michele, Quintens, Hugo, Giuffrida, Vincent, Bramoullé, Clément, sikic, Ivan

Study of a CI Engine for off-road in Diesel-Hydrogen Dual Fuel Configuration

2025-24-0055To be published on 09/07/2025

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 injection (PFI), 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

Zero-Carbon Port Fuelling for Heavy Propulsion Through a Recuperated Split Cycle Engine

2025-24-0044To be published on 09/07/2025

To meet the de-carbonisation and emissions targets for HD vehicles and marine engines, this research presents new experimental results derived from an engine designed to replicate the expansion cylinder of a Recuperated Split Cycle Engine (RSCE). The RSCE separates compression and expansion cylinders, enabling quasi-isothermal compression and internal waste heat recovery via a recuperator. Expander inlet-port conditions are ~30 bar/400⁰C, and subsequent energetic mixing during induction into the cylinder supports vaporisation and development of homogeneous conditions. The experimental RSCE results are extended using a validated Ansys Chemkin-Pro Multi-Zone (MZ) digital engine twin enabling integration of detailed chemical kinetics with the spatial resolution of the combustion process. This was done to compare the benefits and drawbacks of partial substitution of diesel fuel energy with either ammonia or hydrogen (at 5 and 10%Vol air and constant load) for system modelling, and

Wylie, Elisa, Panesar, Angad

Lifting the key functional figures concerning performance and efficiency for 2nd Gen. H2 engines for On- and Off-highway installations by tailored engineering measures

2025-24-0049To be published on 09/07/2025

To curb global warming and meet stricter greenhouse gas emission standards all over the globe, it is essential to minimize the carbon footprint of applications in the mobility and transport segment. The demands on mobility, transportation and services are constantly increasing in line with worldwide population growth and the corresponding need for economic prosperity. This ongoing trend will lead to a significant increase in energy requirements for mobility-related applications in the upcoming time, despite all efficiency improvements. The timely introduction and accelerated spread of low-carbon/carbon-neutral energy sources is therefore of crucial importance. In addition to the switch to electric propulsion systems, particularly in the light-duty vehicle sector, the use of advanced and optimized hydrogen (H2)-powered internal combustion engines (ICE) represents a parallel, compatible technical option, as these applications will also meet the most stringent requirements in terms of

Koerfer, Thomas, Zimmer, Pascal, Li, Zhengling, Pischinger, Stefan, Lückerath, Moritz

Investigation of the Combustion Process of a Thermally Conditioned Active Prechamber in Monovalent Operation with Ammonia

2025-24-0028To be published on 09/07/2025

The debate over synthetic fuels is intense especially in sectors with a high energy demand like maritime. Hydrogen production from renewable sources is growing, but immediate measures for decarbonization are needed. In this context, the project MethMag was funded, and a gas engine for methane combustion with an innovative cooling concept and a purged pre-chamber spark plug was virtually developed. Validation with data from the test bench demonstrates that the simulations accurately represent the operating conditions. This combustion process is adapted for ammonia, which is being considered as a climate-friendly fuel of the future, particularly in maritime transportation. This fuel faces significant combustion challenges and is therefore mostly considered in complex, bivalent systems. In particular, the pre-chamber is examined regarding the ignitability of ammonia. The transition to ammonia highlights the need for further adjustments. The geometry of the pre-chamber cap significantly

Rothe, Paul, Bikas, Georgios, Mauss, Fabian

Enhancing Ammonia Combustion in Heavy-Duty SI Engines: A 3D-CFD Study on Pre-Chamber Ignition, Methane Addition, and Spark Timing Optimization

2025-24-0006To be published on 09/07/2025

Ammonia shows great potential as a zero-carbon fuel for internal combustion engines, but its low flame speed and heat of combustion present challenges for efficient operation. The pre-chamber spark-ignition (PCSI) system offers a promising solution by creating multiple ignition points in the main chamber, enhancing combustion efficiency while enabling lean-burn operation. This study numerically investigates the combustion characteristics and emissions of an active PCSI heavy-duty engine fueled with ammonia and ammonia-methane mixtures using 3D-CFD simulations. Methane, with its higher flame speed, improves combustion propagation and engine performance when mixed with ammonia. A newly developed chemical kinetics mechanism is used to study the interaction between the two fuels. The simulations begin with a methane-fueled case validated against experimental data, followed by an exploration of various ammonia-methane blends. A detailed spark advance (SA) analysis is performed, with SA

Palomba, Marco, Salahi, Mohammad Mahdi, Cameretti, Maria Cristina, Mahmoudzadeh Andwari, Amin

Development of European high-performance permanent magnets for automotive traction electric motors incorporating short loop recycled rare earths

2025-24-0128To be published on 09/07/2025

The fast electrification of the automotive industry, as a preferred solution for the environmental impact reduction, increases the availability and supply constraints on the materials used in the electric powertrains, with the rare earths on the top of the Critical Raw Material act list. The question of European (EU) sovereignty arises since these metals are geographically concentrated outside Europe. Authors present results obtained within the HORIZON EUROPE MAGELLAN project which aims at developing, qualifying and producing EU high-performance permanent magnets (PMs) for automotive industry, incorporating short loop recycled rare earths elements (REE), being recyclable themselves and using Life Cycle Assessment (LCA) from the very start as a development and industrialization guidance. This approach targets circularity, resilience and decarbonation. Developed recycled PMs contain 25% wt. of recycled materials and are supported by a complete ecosystem including automotive traction

Abdelli, Abdenour, Keller, Frederico, Tosoni, Olivier, Klenner, Jan, Milosavljevic, Misa, Cascio, Fulvio

Comparison Between Spark-Ignition and Passive Pre-Chamber Combustion in a Heavy-Duty Engine at Different Speeds, Loads, and EGR Dilutions

2025-24-0030To be published on 09/07/2025

Passive pre-chamber combustion has proven to have the potential to improve efficiency and emissions when compared to conventional spark ignition engines. This work is focused on comparing the performance of both technologies at different engine speeds, loads, and EGR dilutions. These variables were tested independently while keeping operational conditions steady and spark timing fixed. The results showed that the variables followed the trends in the literature: increasing engine speed accelerates combustion, increasing the load increases combustion peak pressure and NOx emissions, and combustion duration lengthens with higher EGR dilution rate. Comparably, passive pre-chamber combustion appears to be the less sensitive to operating conditions and shows more robust ignition behaviour. However, spark ignition achieved better efficiency overall even when accounting for its slightly higher compression ratio, owing primarily to lower heat transfer losses. In terms of emissions, passive pre

Fong Cisneros, Eric J., Hlaing, Ponnya, AlRamadan, Abdullah, Cenker, Emre, Turner, James WG

Machine Learning-Enhanced Combustion Modelling: Predicting Ethanol Effects in a Single-Cylinder Research Engine

2025-24-0026To be published on 09/07/2025

Recent studies highlight the urgent need to reduce greenhouse gas (GHG) emissions to mitigate the impacts of global warming and climate change. As a major contributor, the transport sector plays a vital role in these efforts. Ethanol emerges as a promising fuel for decarbonizing hard-to-electrify propulsion sectors, thanks to its sustainable production pathways and favourable physical and combustion properties—such as energy density, rapid burning velocity, and high knock resistance. This work proposes a methodology to enable the possibility of replicating the combustion behaviour of ethanol in a 1D CFD simulation environment representative of a single-cylinder research engine. Spark-ignition combustion is simulated through the Eddy Burn-Up combustion model previously calibrated for standard fossil gasoline. The combustion model features a laminar flame speed neural network, trained and tested through reference chemical kinetics simulations. The combustion model showed great accuracy

Ferrari, Lorenzo, Sammito, Giuseppe, Fischer, Marcus, Cavina, Nicolò

Numerical study of mixing, combustion and NOx emissions in a DI high performance hydrogen engine operated at stoichiometry

2025-24-0010To be published on 09/07/2025

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 (ICE) with hydrogen. The burning of a hydrogen-air mixture inside the combustion chamber reduces to minimal amount the production carbon emissions and of particulate matter that are produced by the presence of lubricant oil only. However, nitrogen oxides remain among the products of the chemical reactions because of the temperatures reached by the end-gases. In high performance ICE, the pursuit for high-specific power burning stoichiometric mixtures is hindered by the need to reduce NOx, as this pollutant drastically reduces 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 in stoichiometric conditions. The

Baudone, Antonio Denny, Marini, Alessandro, Sfriso, Stefano, Falcinelli, Francesco, Mortellaro, Fabio, Tonelli, Roberto, Breda, Sebastiano

Optimization of the Injection Strategy to Enhance Mixture Formation in a 4-Cylinder Methanol Engine by means of a 3D-CFD Virtual Engine Test Bench

2025-24-0077To be published on 09/07/2025

Emissions reduction and carbon neutrality are two obligations to fulfil in order to ensure a clean and bearable planet for the future. The diversification of energy carriers is one of the keys to achieving a concrete and time-effective solution and methanol can be one of the possible ways to reach carbon neutrality, showing many positive characteristics to be used as fuel for internal combustion engines. Using Methanol as a fuel or in a blend can greatly reduce exhaust emissions, with a great impact on CO2 emissions. Nevertheless, some challenges have to be overcome to exploit the whole potential of methanol as a fuel. The aim of this work is to investigate which aspects can improve the mixture formation using a 4-cylinder gasoline engine fuelled with Methanol. The study was conducted numerically, by means of a virtual engine test bench, considering two different operating points, the former at high engine speed and load, the latter in a lower load region of the engine map. As the

Tortorella, Cristian, Rossi, Edoardo, Vacca, Antonino, Chiodi, Marco, Kulzer, Andre Casal

Influence of Gas Pressure Levels on Injection Timing, Combustion Anomalies, and Emissions of a Hydrogen Gas Engine

2025-24-0053To be published on 09/07/2025

A former diesel heavy duty engine was retrofitted to hydrogen operation in attempt to simultaneously facilitate the shift from fossil to renewable fuels and maximize the quantity of reusable engine parts. Changing the fuel in this case does not make a properly working engine, the burning process needs to be in premixed flame. Rather than diffusional flame. Therefor an additional ignition source is necessary. A well-known characteristic of hydrogen is the low need for ignition energy and the wide range of ignitable air/ fuel ratios. Both need to be considered to reach a diesel engine equivalent performance. In spark ignited internal combustion engines, port fuel injection (PFI) and direct injection (DI) are commonly used. Some disadvantages such as weak volumetric efficiency and combustion abnormal phenomena like backfire connected to PFI. To further improve the volumetric efficiency, high boost pressures are needed. To maximize volumetric efficiency injection timing after intake valve

Rößlhuemer, Raphael, Fellner, Felix, Fitz, Patrick

The VERT GPF-Retrofit Program for Cleaner Urban Mobility within the HORIZON Europe AeroSolfd Project

2025-24-0095To be published on 09/07/2025

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 association VERT focuses on reducing tailpipe emissions using state-of-the-art Gasoline Particulate Filter (GPF) technology featuring an uncoated CORNING ceramic multicell wall-flow filter. VERT, in partnership with HJS, CPK, BFH, and CORNING, 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 (WLTC and RDE) and real-world driving cycles. Fifty gasoline vehicles (GDI and PFI) were retrofitted across Germany, Switzerland, Israel, and Denmark. Over a 6- to 8-month operational period, no issues were observed with filter

Rubino, Lauretta, Mayer, Andreas C., Lutz, Thomas W., Czerwinski, Jan, Larsen, Lars C.

Using Turbogenerators for Energy Recovery in Turbocharged Hybrid Powertrains

2025-24-0100To be published on 09/07/2025

Modern internal combustion engines have become heavily downsized, with their overall volumetric efficiency being increased by implementing highly efficient turbochargers. Since such turbochargers can enhance performance they can further optimize vehicle drivability. Conventional turbochargers are equipped with a wastegate through which the exhaust gases are expelled in order to control boost pressure, such a mode of operation results in an inevitable loss of exhaust gas energy. As vehicle technology has advanced, the need for CO2 emission control has led to the development of hybrid powertrains. The primary focus of this paper is to replace the wastegate in a conventional turbocharger by introducing either a turbogenerator or an e-turbocharger. A turbogenerator is an advanced system that integrates a turbocharger with an electrical generator and is mounted so that its flow is in parallel to the turbocharger turbine. The gases which would previously have been expelled via the wastegate

Kodaboina, Raghu Vamsi, Turner, James, Vorraro, Giovanni

Experimental and numerical study on the performance and exhaust emissions of a Single-Cylinder Natural Gas Large Bore Engine equipped with Passive Pre-chamber

2025-24-0022To be published on 09/07/2025

The maritime industry is among the most energy-intensive sectors, and achieving fleet decarbonization is crucial to significantly reduce greenhouse gas emissions. As a transitional fuel, natural gas (NG) presents a viable short-to-midterm solution. Compared to conventional marine fuels, NG has the potential to lower carbon dioxide emissions by approximately 20–30%. However, to fully leverage this potential on carbon footprint reduction, substantial advancements in combustion technologies are required. One promising approach to enhance the efficiency of spark-ignited (SI) NG engines is the implementation of Passive Pre-Chamber (PPC) technology. This strategy enables leaner combustion, improving thermal efficiency, mitigating the occurrence of knocking, and reducing NOx emissions. This study presents both experimental and numerical investigations to analyze the impact of charge dilution and ignition timing on the performance and emissions of a single-cylinder prototype NG PPC SI engine

Marchitto, Luca, Pesce, Francesco, Accurso, Francesco, Tornatore, Cinzia, Gorietti, Valentina, Buzzi, Luca, Grosso, Alessandro, Luci, Matteo, Napolitano, Pierpaolo, Pennino, Vincenzo, Beatrice, CARLO, Di Domenico, Davide, Giardino, Angelo

Cylinder Balancing Algorithms: Enabling the Transition to Future Fuels in Large-Bore Spark-Ignited Engines

2025-24-0017To be published on 09/07/2025

Large-bore spark-ignited engines equipped with individual cylinder injection systems requiring advanced balancing strategies to achieve optimal combustion performance and mitigate risks associated with abnormal combustion phenomena. The integration of highly reactive fuels, such as hydrogen, introduces additional challenges for high-power-density, low-speed engines. This study investigates closed-loop cylinder balancing strategies utilizing real-time cylinder pressure feedback to optimize engine operation. Key performance metrics were evaluated on a 20-cylinder stationary engine (8.5 MW electrical power) under diverse operating conditions, including variations in gas quality and ambient factors. The results indicate that the tested balancing methods converge toward an increase in average knock intensity across all cylinders, primarily due to fluctuations in gas composition and environmental conditions. Furthermore, the study demonstrates that a well-balanced engine offers significant

Martelli, André, Penaranda, Alexander, Martinez, Santiago, Zabeu, Clayton, Salvador, Roberto

ML-based Identification of Lactones & Impact of Blends on Performance and Emissions in a Spark-Ignition CFR Engine

2025-24-0071To be published on 09/07/2025

The identification of sustainable fuels that exhibit optimal physicochemical properties, can be synthesized from widely available feedstocks, enable cost-effective large-scale production, and integrate seamlessly with existing infrastructure is essential for reducing global carbon emissions. Given their high energy density, efficient handling, and versatility across applications, renewable liquid fuels remain a critical component of even the most ambitious energy transition scenarios. Lactones, cyclic esters derived from the esterification of hydroxycarboxylic acids, feature a ring structure incorporating both a carbonyl group (C=O) and an ether oxygen (O). Variations in ring size and carbon chain length significantly influence their physicochemical properties, which in turn affect their performance in internal combustion engines. According to predictive models based on artificial neural networks, valerolactone, caprolactone, and helptalactone isomers show promise as fuels in spark

Sirna, Amanda, Loprete, Jason, Assanis, Dimitris, Patel, Rutvi, Mack, J. Hunter

Combustion Characteristics and Efficiency of a Turbocharged Hydrogen-Fueled Internal Combustion Engine Under Ultra-Lean, High-Load Conditions

2025-24-0048To be published on 09/07/2025

The transportation industry seeks sustainable alternatives to fossil fuels, and hydrogen internal combustion engines (H₂ICE) have emerged as a practical solution. They offer near carbon-free operation while integrating with existing engine technology and infrastructure. Thanks to hydrogen’s specific properties, lean combustion can be achieved, significantly reducing NOx emissions. However, operating a commercial engine under ultra-lean conditions at high load presents challenges, particularly in maintaining volumetric efficiency and power density. This study analyzes the combustion behavior, NOx emissions, and loss mechanisms in a four-cylinder, direct-injection, hydrogen-fueled engine, equipped with a variable geometry turbine (VGT). The engine was tested at three BMEP levels (8, 10, and 12 bar) under ultra-lean conditions, with lambda varied between 2.2 and 3.6. Unlike conventional approaches, fuel mass was held constant at each load, and lambda was adjusted by varying intake air

Azizianamiri, Sobhan, Tauzia, Xavier, Maiboom, Alain, Perrot, Nicolas

Exhaust thermal management in a dual-fuel marine engine via fully variable valve actuation and wastegate lambda control

2025-24-0085To be published on 09/07/2025

With the growing focus on maritime decarbonization, dual-fuel combustion emerges as a promising solution due to its adaptability and minimal system modifications. However, alternative fuels like natural gas pose challenges such as methane slip (CH4), which has a greater impact on global warming than CO2. To mitigate methane emissions, conventional aftertreatment systems might incorporate a methane oxidation catalyst. However, effective methane oxidation requires high temperatures of approximately 450 °C. Therefore, exhaust thermal management (ETM) is crucial for maintaining high exhaust gas temperatures and ensuring high conversion efficiency. This study investigates the effectiveness of fully variable valve actuation (VVA) including variable exhaust valve opening (VEVO) and early intake valve opening (EIVC) along with lambda control via wastegate control. The primary objective is to evaluate the impact of each strategy on elevating exhaust gas temperature (EGT) while considering

Soleimani, Amir, Kim, Jeyoung, Axelsson, Martin, Hyvonen, Jari, Mikulski, Maciej

Numerical and Experimental Investigation of a Pre-chamber Igniter for Enhanced Low Load Stability in Internal Combustion Engines

2025-24-0002To be published on 09/07/2025

Developing innovative technologies offers a crucial opportunity to improve Internal Combustion Engines’ performance while significantly reducing harmful emissions, contributing to a more sustainable future. The replacement of the standard spark plug in externally ignited engines for passenger vehicles with a prechamber igniter is a well-known combustion accelerator, facilitating the increase of engine efficiency especially at high loads. However, prechamber ignition technology has not yet been widely adopted in the market, primarily due to the difficulty of achieving stable operation at lower engine loads. The gas exchange in the passive prechamber was studied using a combination of numerical modelling and experimental methods. A better understanding of the flow and mixture conditions is needed to improve stability of the prechamber igniter in low load operation points. Accessing those parameters experimentally comes with high efforts for the test bench design and operation. To

Fellner, Felix, Härtl, Martin, Jaensch, Malte, Rothbauer, Rainer, D'Elia, Matteo, Nambully, Suresh Kumar, Burgo Beiro, Marcos

Investigation of a Lambda Leap Strategy for Hydrogen Internal Combustion Engines to Balance Efficiency, Performance, and Vehicle Packaging

2025-24-0070To be published on 09/07/2025

The paper reports investigations into employing a “lambda leap” strategy for hydrogen internal combustion engines (H2ICEs), wherein inherently low NOx emissions are afforded at light load via operation at lambda 2.5 or leaner, and at higher load by operation at stoichiometry with a three-way catalyst. This approach means it is necessary under transient operation to “leap” between high values of lambda and stoichiometry from one cycle to the next, in order to avoid completely the area where high combustion NOx is generated away from lambda = 1; this is because lean catalysis of NOx will be extremely challenging there. The requirements for the cam profiles and valvetrain hardware to achieve this strategy are discussed, and a 2.0 litre in-line 4-cylinder engine configuration with the necessary valve gear functionality is modelled. The efficiency results on an operating map are then presented. In turn, this data is used to model the hydrogen consumption of two vehicles (one a saloon car

Fong Cisneros, Eric J., Kodaboina, Raghu Vamsi, Vorraro, Giovanni, Turner, James W. G.

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