Browse Topic: Environment

Items (41,751)

Brake System Homologation: A Holistic, Simulation-based Approach

2025-01-0351To be published on 09/15/2025

To comply with EU7 in a first step brake systems of newly homologated passenger cars and light commercial vehicles up to 3.5 tons must fulfil the upcoming certification limits, according to the EU7 implementation timeline. Based on a wide range of brake emission measurements since 2022, it can be seen that almost no brake system is fulfilling these currently foreseen limits. Brakes have been optimized for decades now for mainly performance and comfort improvements, but now legal emission requirements are acting as a game changer and huge efforts will be necessary to fulfil new and tradtitional purposes, which are causing new modelling and testing approaches to understand the complete vehicle picture with all its attributes. A possible contribution to solving this challenge is the use of the vehicle-specific individual friction brake share coefficient ("iFBSC"), which is currently mostly evaluated by performing a WLTP-Brake cycle on a roller testbed and analysing the relative amount of

Grojer, Bernd

Improving the Comparability of Brake Wear Solid Particle and Total Particle Number Emission Measurement

2025-01-0362To be published on 09/15/2025

Authors (not in final order): Sampsa Martikainen, Madlen Pramstrahler, Christoph Weidinger, Christian Wanek-Rüdiger, Michael Huber, Andreas Rainer      The United Nations Global Technical Regulation (GTR) defines the framework for brake wear emission measurements. The definitions and limits for the emission measurement system, such as sampling configuration and allowed background concentration, are a part of it. The particle number (PN) measurement is divided into Solid Particle Number (SPN) and Total Particle Number (TPN), referring to the emitted particles that exclude, or include, volatile particle matter, respectively. In this study we present conclusions drawn from a large set (>700) of PN emission factors, regarding the comparability of SPN and TPN, uniformity of particle concentration in the sample transport tunnel, and the effect of background concentration on the final emission result. Additionally, we evaluate the suitability of a flow splitter in the brake wear PN

Martikainen, Sampsa, Pramstrahler, Madlen, Weidinger, Christoph, Rainer, Andreas, Engler, Dieter, Huber, Michael

Effects of Moisture Behavior on Corrosion Stiction in Friction Materials

2025-01-0333To be published on 09/15/2025

This study investigates the correlation between moisture behavior and corrosion stiction mechanisms in NAO friction materials. While previous studies on corrosion stiction have primarily focused on electrochemical approaches, this study aims to elucidate the mechanism by examining moisture behavior within the friction material. Although recent research has explored changes in pad properties in humid environments, most studies have primarily focused on variations in pad stiffness and friction coefficient. To date, no studies have investigated the behavior of moisture within pads using Fick’s Second Law and its impact on corrosion stiction. In this study, Fick’s Second Law was applied to model moisture behavior in friction materials. The diffusion coefficient and maximum moisture content were quantified, revealing that moisture behavior in the friction material can be divided into two distinct stages: one following Fick’s Second Law and the other not. For NAO friction materials

Choi, Nakcheon, Ju, Joungsu, Youn, Deokki

Achieving Euro 7 Compliance: Cost-Effective Brake Wear Particle Emissions and Performance with FNC-Smart ONC® GCI Rotors

2025-01-0332To be published on 09/15/2025

Over the past few years, NITREX has developed an advanced ferritic nitrocarburizing process combined with a specialized post-oxidation treatment known as FNC + Smart ONC®. This innovative approach allows the use of grey cast iron brake rotors in their original form, 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. We have rigorously tested these rotors according to several industry standards, including SAE J2707B (Block Wear Test including Highway), GRPE-81-12 Emission Test (Full WLTP Brake Cycle 6 Times), and SAE J2522 (AK-Master Performance). These tests were designed to compare the behavior of treated rotors against standard untreated rotors, as well as to evaluate performance with different lining materials. Additionally, our process addresses the issue of corrosion, which is particularly relevant for brake rotors that experience less use in

Winter, Karl-Michael, Holly, Mike

Water Interaction and its Effect on the Tribological Behavior of NAO friction materials.

2025-01-0336To be published on 09/15/2025

Moisture is known to be a relevant factor during a friction material life, affecting tribological behaviors such as friction coefficient and torque variations. In this study we investigated the interaction between friction materials and water; employing various techniques such as contact angle measurements, soaking, and exposure to controlled environmental condition changes. For this study, specifically selected materials were studied to highlight differences and understand mechanisms. Material modifications, in particular, organic content and hydrophobic agents, were examined. Characterization results showed that brake pads hydrophobicity can be influenced by water interaction conditions; even low-wettability surfaces, such as those treated with hydrophobic modifiers, can still absorb water depending on internal factors (e.g., porosity) and external conditions (e.g., contact time, humidity). Additionally, we investigated the capacity of a friction material to adsorb water and desorb

Iodice, Valentina, Durando, Pietro, Balestra, Simone, Pellerej, Diego

A Novel Simulation Method for Vehicle Brake Wear Emissions

2025-01-0361To be published on 09/15/2025

The effective reduction of particulate emissions from modern vehicles has shifted the focus to tire, brake, road 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 equations integrated in the

Landl, Lukas, Ketan, Enis, Hausberger, Stefan, Dippold, Martin

Enhancing robustness of electro-hydraulic Brake-by-Wire actuators via linear Active Disturbance Rejection Control

2025-01-0341To be published on 09/15/2025

In recent years, motorsport has increasingly focused on environmental concerns, leading to the rise of hybrid and fully electric competitions. In this scenario, electric motors and batteries take a crucial role in reducing the environmental impact by recovering energy during braking. However, due to inherent limitations, motors and battery cannot fully capture all braking power, necessitating the use of standard friction brakes. To achieve an efficient balance between electric motors and friction brakes, the brake pressure can no longer be directly controlled by the driver. Instead, it must be computed by the Vehicle Control Unit (VCU) and sent to a smart actuator, i.e. the Brake-By-Wire (BBW), which ensures that the required pressure is applied. The standard approach to achieve precise pressure control is to design a nested Proportional-Integral-Derivative (PID) control architecture, which requires an accurate nominal model of the system dynamics to meet the desired tracking

Gimondi, Alex, Dubbini, Alberto, Riva, Giorgio, Cantoni, Carlo

Challenges in Quantifying Tire Wear Particle Emissions on an Outer Drum Test Bed

2025-01-0352To be published on 09/15/2025

Tire wear is a major source of microplastics and airborne particles (<10 µm), posing environmental and health risks. Accurate quantification is essential for regulatory control. This study develops a method to measure tire wear and tire wear particles on an outer drum test bed while achieving realistic wear rates. A key challenge is the necessity of de-gumming methods, such as talcum powder, to prevent tire adhesion to the drum. However, this complicates emission measurements. The test bed at TU Graz features an enclosure with flow-optimized baseplates and AirKnifes to minimize background emissions. The sampling system, compliant with GTR-24 (brake wear), includes two AVL Particle Counters, two PM-Samplers, and an ELPI+ for size distribution analysis. Results show that background emission reduction is critical for accurate measurement. The de-gumming method increased tire wear rates by a factor of 10 but introduced additional particle sources. Size distribution analysis revealed clear

Schubert, Ludwig, Arias Torres, María Alejandra, Bigl, Stephan, Steiner, Gerald, Huber, Michael, Lex, Cornelia

Enhancing Brake Pedal Feel in Hydraulic Brake high tonnage Vehicles Using Hydro-Actuated Vacuum Assist Booster

2025-01-0359To be published on 09/15/2025

Brake pedal feel is very important factor for driver brake application confidence. In Indian low and medium truck application, driver is loading vehicle with max overload condition and, pedal feel deteriorated with increased in vehicle GVW. However, brake system aggregate size increment with respective weight increment is not feasible due to modulator architecture of vehicle. To overcome this concern, we have developed innovative solution “Remote hydro-actuated vacuum assist booster”. In this proposal, Actuator unit is a hydraulic tandem master cylinder assembled inside driver cabin. The hydro-actuated vacuum assist booster is consisting of slave cylinder and vacuum assist booster with hydraulic tandem master cylinder (HAVB) located on chassis. Driver’s foot input force is transferred from the brake pedal to the hydro-actuated vacuum assist booster (HAVB) via an actuator unit. The hydro actuated vacuum assist boosters have amplified driver input force and generate hydraulic pressure

Sonar, Milind, Shaikh, Matin Hanif

Effect of Casting Microstructure on the Mechanical Performance of Recycled EN AC-43200 Al-Si Alloy

2025-01-0357To be published on 09/15/2025

Nowadays, the automotive industry is moving toward the reduction of CO2 emissions implementing different strategies. Beyond the direct reduction of emissions from the vehicles, an important role is played by the production of parts made with recycled materials. This is particularly relevant for automotive components (e.g., brake calipers and steering knuckles) produced using cast Aluminium-Silicon (Al-Si) alloys, whose primary production from bauxite is highly energy-intensive. However, recycled cast Al-Si alloys could have different mechanical performances with respect to their primary counterparts, due to the presence of impurity elements from the recycling process. For this reason, it becomes fundamental to study the effect of different casting parameters (e.g., molten alloy temperature, sprue design and mould temperature) on the solidification microstructure of recycled, cast Al-Si alloys and, as a consequence, on the mechanical performances of the material. In this context, this

Pavesi, Arianna, Barella, Silvia, D'Errico, Fabrizio, Bonfanti, Andrea, Bertasi, Federico

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, Ristow Hadlich, Rodrigo, Assanis, Dimitris, Patel, Rutvi, Mack, J. Hunter

New Hybrid Powertrain architectures for European Passenger Car Market

2025-24-0097To be published on 09/07/2025

The present paper describes a comparative analysis of different hybrid architectures and optimization of the total energy efficiency on passenger car applications. The first part of the study is devoted to providing simulation results of different type of hybrid architecture, highlighting their advantages and disadvantages with numerical simulation on different type of use cases, not only on legislated cycles but also on RDE use cases representative of customer behavior. The outputs of the usage of Passenger cars for the EU market highlights interesting results not yet published. The above mentioned analysis opens the window to (1) study new control strategies for optimizing the total energy consumption in different scenarios and (2) investigate options for maximizing the efficiency of the overall powertrain system.

Amati, Nicola, Marello, Omar, Mancarella, Alessandro, Cavallaro, Davide, Ianni, Luca, Cascone, Claudio, Paulides, Johannes JH

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 ignition technologies offers a crucial opportunity to improve the performance of internal combustion engines while significantly reducing harmful emissions, contributing to a more sustainable future. The replacement of the standard spark plug with a pre-chamber igniter is a well-known combustion accelerator for externally ignited engines for passenger vehicles. An increase in engine efficiency, especially at high loads, can be realized. However, pre-chamber ignition technology has not yet been widely adopted in the market, primarily due to the difficulty of achieving stable operation at lower engine loads. A better understanding of the flow and mixture conditions is needed to improve the combustion stability with the pre-chamber igniter in low-load operating conditions. The gas exchange in the passive pre-chamber was studied using a combination of numerical modelling and experimental methods. Accessing those parameters experimentally requires a high effort in test

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

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, Prager, Maximilian, Jaensch, Malte

Water Injection Effects on a Heavy-Duty Hydrogen SI Engine

2025-24-0050To be published on 09/07/2025

Hydrogen engines have gained interest recently, as they present a promising alternative for the decarbonization of heavy-duty transport, aligning with carbon neutrality regulations. This study investigates the effects of inlet manifold water injection on a heavy-duty hydrogen fueled spark ignition single cylinder engine, focusing on moderating abnormal hydrogen combustion and its impact on performance, thermal efficiency and exhaust emissions. Water injection has been identified as a potential solution to mitigate the challenges associated with hydrogen combustion, such as pre-ignition and knock, by reducing the reactivity of the mixture (reducing temperature and increasing the dilution). The lower reactivity of the mixture allows running richer lambdas without spontaneous preignition mitigating boosting requirements for full load and transient performance. Experimental results demonstrate that water injection significantly improves engine performance, thermal efficiency and exhaust

Peñin Garcia, Alfonso Jose, Valls Claramunt, Carles, Rivas PhD, Manuel, Birnstingl, Johannes, Wieser, Martin, Martin, Jaime, Novella, Ricardo

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

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, Vorraro, Giovanni, Turner, James W. G.

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.

Ammonia Combustion with Ignition Improvement Measures in a High-Speed Marine Application

2025-24-0025To be published on 09/07/2025

Ammonia (NH3) has gained significant attention as a zero-carbon fuel which is capable of supporting global decarbonization goals, especially in the maritime transportation and power generation sectors. Its hydrogen density, storage feasibility, established production methods, and transportation infrastructure are key benefits which contribute to its potential both as a hydrogen carrier and as a direct fuel. The study investigates the combustion characteristics and emission profiles of ammonia on a spark ignited 2.13L single cylinder engine with the goal of evaluating ammonia as a single fuel. This displacement is representative of the typical cylinder displacement of small to mid-size engines for marine applications on sportfishing boats and as auxiliary power units. Challenges to consider for ammonia combustion are its high ignition energy requirement and low laminar flame velocity. Several methods were employed to compensate for these properties such as increasing compression ratio

Li, Zhengling, Lückerath, Moritz, Pischinger, Stefan, Boberic, Aleksandar, Franzke, Bjoern, Dhongde, Avnish, Jagodzinski, Bartosch, Burrows, John, Korkmaz, Metin

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

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

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 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

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

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

Upcoming global emissions regulations demand innovation in heavy-duty road and marine transport. This research explores emissions-compliant concepts using both experiments and simulations focused on the Recuperated Split Cycle Engine (RSCE), which separates compression and expansion to enable internal heat recovery and quasi-isothermal compression. A single-cylinder research engine representing the expansion cylinder of an RSCE demonstrated direct injection diesel and port injection hydrogen co-firing. A validated Chemkin-Pro Multi-Zone model first reproduced, then extended this work, evaluating partial diesel substitution with hydrogen or ammonia alongside secondary working fluids (SWF’s liquid N₂, H₂O, NH₃). For the extension, two variants of the split cycle architecture were employed; the RSCE in combination with hydrogen fueling for the heavy-duty road sector, and the novel recuperated reformed split cycle engine (R2SCE), a new architectural and simulation contribution enabling on

Wylie, Elisa, Panesar, Angad

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

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

Decarbonizing the transport sector requires solutions that reduce CO₂ emissions while improving the efficiency of existing engine platforms. This study explores a retrofit strategy in which a heavy-duty diesel engine is converted to Otto-cycle operation and equipped with a passive pre-chamber combustion (PPCC) system. Methanol was used as the fuel due to its high octane number, low carbon intensity, and favourable combustion properties. The performance of the PPCC system is experimentally compared to conventional spark ignition (SI) across varying engine speeds, loads, and exhaust gas recirculation (EGR) levels. A dual-dilution strategy, combining lean operation (λ = 1.6) with EGR, was applied to extend dilution tolerance and assess the feasibility of operating near stoichiometry. All tests were conducted under steady-state conditions with fixed spark timing. Results show that PPCC consistently delivers faster combustion than SI across all conditions, with greater stability and reduced

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

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

Dual-fuel combustion is emerging as a promising solution to address the growing focus on maritime decarbonization, because it is adaptable and needs minimal system modifications. However, natural gas as an alternative fuel must deal with the issue of methane slip, because methane has greater global warming potential than CO2. Conventional aftertreatment systems may incorporate a methane oxidation catalyst to mitigate methane emissions, but effective methane oxidation requires high temperatures of approximately 400 °C. Therefore, exhaust thermal management (ETM) is crucial for maintaining high exhaust gas temperature (EGT) and ensuring conversion efficiency. This study investigates the effectiveness of fully variable valve actuation (VVA), including early exhaust valve opening (EEVO) and early intake valve closing (EIVC), along with lambda control via wastegate control. Each strategy’s effect on exhaust gas temperature is evaluated, while considering potential trade-offs with efficiency

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

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

Characterization of Exhaust Gas Recirculation Effects in a Hydrogen-Fueled 4-Cylinder Engine with Direct Injection

2025-24-0052To be published on 09/07/2025

The increasing importance of hydrogen as alternative energy source to reduce CO2 emissions in the transport sector makes its adoption in spark-ignited engines an attractive and cost-efficient alternative to fuel cell-powered vehicles. Lean combustion is the preferred operating strategy for H2-engines in order to achieve performance targets, enhance efficiency and at the same time avoid critical knocking and pre-ignition phenomena. Additionally, an effective approach to lower cylinder temperatures, relevant engine-out NOx emissions and boost pressure requirements at the same time, is an external exhaust gas recirculation (EGR) system. The aim of this work is to analyze and compare the effects of exhaust gas recirculation on the combustion of a lean hydrogen mixture in a turbocharged 4-cylinder H2-ICE with direct injection. For this investigation a load point at 18 bar BMEP and 4000 rpm is selected with and without the utilization of additional external EGR. In this case, a BTE of 38

Schmelcher, Robin, Kulzer, Andre Casal, Gal, Thomas, Vacca, Antonino, Chiodi, Marco, Grabner, Peter, Gschiel, Kevin

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

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

Experimental Study of the Lubricating Oil Impact on the Unsteady Performance of an Automotive Turbocharger

2025-24-0078To be published on 09/07/2025

Turbocharging technique is a key technology for the development of hydrogen engines, allowing high lambda values to reach low NOx emissions. In ultra-lean mixture conditions, the thermal management of the lubricating oil and its cold condition becomes a crucial aspect that cannot be neglected. Accordingly, the impact of different lubricating oils and different lubricant thermal conditions is highlighted referring to the performance of a turbocharging system for automotive application. To this aim, an experimental campaign is conducted at the test bench for components of propulsion systems of the University of Genoa. Tests are performed on a turbocharger equipped with a variable geometry turbine under both steady and unsteady flow conditions, considering different positions of the turbine regulating device. A 4-cylinder engine head was coupled to the turbocharger in order to reproduce the pulsating flow related to the opening and closing of the engine valves. The influence of the

Marelli, Silvia, Usai, Vittorio, Cordalonga, Carla

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

Experimental investigation of the comparison between helium and hydrogen jets exiting a DI outward-opening injector via Schlieren technique

2025-24-0068To be published on 09/07/2025

Hydrogen Internal Combustion Engines (H2ICE) are arising as a potential alternative to conventionally fuelled ICE to reduce the CO2 emissions from the transport sector, with similar or even higher performances and lower emissions. To meet these requirements, the mixing of the hydrogen in the cylinder is a key parameter, especially in the case of ultra-lean combustion. One leverage point to improve the hydrogen mixing in direct injection H2ICE is the targeting of the hydrogen jet. However, the development of the hydrogen jet is still far from being understood and needs to be studied. But the use of hydrogen remains dangerous due to high fire hazard, leading to use of surrogates to allow the jet characterization under safer conditions. Helium is one of these potential surrogates as its density and molecular weight are the closest to the hydrogen ones. This paper deals with the hydrogen-to-helium jets comparison within the framework of the assessment of helium as a potential hydrogen

Coratella, Carlo, Tinchon, Alexis, Hespel, Camille, Dober, Gavin, Foucher, Fabrice

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

Comparison of Ignition Modes to Enable Ammonia Combustion Engines: Multi-Spark, Pre-Chamber, and Dual Fuel

2025-24-0005To be published on 09/07/2025

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.

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

Use of Model-Based Datasets and Neural-Networks to support Real-Time Driving Suggestions System for Components Preservation in Battery Electric Vehicles

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's onboard 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 sensor’ 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

Effects of Varying the Air-Fuel Equivalence Ratio at different EGR-Rates on a Medium-Speed LNG-Diesel Dual-Fuel 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

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

The Effect of the Initial Battery State of Charge on the Performance of a Soft Actor-Critic Energy Management System

2025-24-0104To be published on 09/07/2025

Reinforcement Learning (RL) approaches have gained significant popularity for solving complex optimization problems, such as the design of Energy Management Systems (EMS) in electrified powertrains, thanks to their adaptability and model-free nature. Therefore, this study investigates, through numerical simulations, the performance of an EMS, driven by a Soft Actor-Critic (SAC) RL agent targeting the reduction of CO2 emissions in a Plug-in Hybrid Electric Vehicle (pHEV). The SAC agent stands out with its stochastic policy, which accelerates the training process, boosts controller performance, and effectively handles the inherent uncertainties of vehicle dynamics. To improve generalization, the proposed controller was trained and validated across a wide set of driving scenarios. The robustness of the SAC policy was further demonstrated in charge depleting mode across various initial and final battery energy levels. Performance was then benchmarked against the Dynamic Programming (DP

Tresca, Luigi, Pulvirenti, Luca, Rolando, Luciano

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

Development of a 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 from 2025. The development of advanced technologies and the utilization of alternative fuels for internal combustion engines play a key role in the short- to mid- term in complying with such regulations and supporting sustainable transition of the transportation sector. 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 began with the virtual development and optimization of the entire combustion system encompassing bowl shapes, injector nozzles, and intake port specifications, leveraging a Machine Learning approach based on high-fidelity 3D CFD combustion models. Two virtually optimized combustion system “recipes” have been identified and then

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

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 and fuels are needed to design ultra-low emissions 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 and near zero NOx emissions, thus enabling H2-ICE powered vehicles to be zero-impact emitting technology solution. Selective Catalytic Reduction by using NH3 as the reducing agent is the most effective control technology for NOx abatement. Nevertheless, ongoing research and innovation are critical

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

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 develops a multilevel control architecture that optimizes fuel economy and minimizes emissions in fuel cell hybrid heavy-duty vehicles, equipped with proton exchange membrane fuel cell and battery pack as main power sources. The detailed fuel cell system model incorporates reactants 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, membrane water content and differential pressure between the cathode and anode. By identifying optimal setpoints for key control variables, this methodology enables the development of accurate control maps for actuator management

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

AeroSolfd: Advancing Air Quality through Retrofitted Gasoline Particulate Filters – Insights from Laboratory and Real-World Evaluations

2025-24-0088To be published on 09/07/2025

The AeroSolfd project, an EU-funded initiative, aims to improve air quality by reducing particulate emissions from in-use light-duty vehicles (LDVs). In response to growing concerns over air pollution and its environmental and health impacts, the project focuses on retrofitting Gasoline Particulate Filters (GPFs) as a viable solution. A key component of the project was an in-depth measurement campaign conducted at the BFH Exhaust Emissions Test Center on four representative vehicles—two with direct petrol injection and two with intake manifold injection. The campaign assessed non-aged GPFs under laboratory conditions using the Worldwide Harmonized Light Vehicles Test Procedure (WLTC) and Steady State Cycle (SSC), as well as in real driving environments (RDE). Fourier-Transform Infrared Spectroscopy (FTIR) was used to analyze non-regulated emissions. The results demonstrated a significant reduction in particle numbers without adverse effects on gaseous emissions. Beyond controlled

Engelmann, Danilo, Mayer, Andreas, Comte, Pierre, Rubino, Lauretta, Larsen, Lars

Optimum design and sizing approach for a series-hybrid vehicle

2025-24-0099To be published on 09/07/2025

The need to reduce pollutant emissions has pushed the automotive industry towards sustainable mobility promoting new technological solutions, among which the use of hybrid powertrains stands out. The development of a hybrid architecture is very complex and demands proper components sizing and the determination of optimized power-split strategies among different power sources, for example: Internal Combustion Engine (ICE), electric generator/motor and batteries. Moreover, the experimental analysis regarding performance and emissions requires that the whole propulsive system must be set up on the test bench, hence, negatively affecting the cost of the entire design phase. In this scenario, an optimum design and sizing approach for a series-hybrid electric vehicle (S-HEV) is proposed aiming at a design cost reduction. The presented procedure relies on numerical modelling of the hybrid powertrain and on the optimization of the fuel consumption and the driving range. The series-hybrid

Lisi, Leonardo, Saponaro, Gianmarco, Episcopo, Domenico, Torresi, Marco, Camporeale, Sergio Mario

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 occasionally 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 associated

Zafeiridis, Menelaos, Alexiadou, Panagiota, Koltsakis, Grigorios

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

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

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

Experimental Investigations on the Effects of Injector Orientation in a Diesel-Gasoline-Fuelled Premixed Charge Compression Ignition Engine

2025-24-0043To be published on 09/07/2025

Premixed charge compression ignition (PCCI) presents a promising alternative to conventional diesel combustion (CDC), substantially reducing pollutant levels by lowering the local in-cylinder temperature and enhancing fuel-air mixing. A significant challenge in PCCI is controlling the initiation of combustion, along with a narrow operating load range due to early ignition and knocking combustion at the higher load when using high-reactivity diesel fuel. This poses an obstacle to successfully implementing the PCCI combustion mode engine. In the present study, experimental investigations are carried out in a light-duty diesel engine in PCCI mode using three fuel blends, 0% (G0D100), 10% (G10D90) and 20% (G20D80) gasoline in diesel on a volume basis, and exhaust gas recirculation (EGR) and water vapor as charge diluents. A common rail direct injection (CRDi) system replaces the existing mechanical fuel injection, and the compression ratio is decreased from 17.5 to 15 to achieve the PCCI

Ranjan, Ashish Pratap, Krishnasamy, Anand

Analysis of Combustion Characteristics and Performance of a Multi-Cylinder Engine Operating on Syngas/Diesel in Dual-Fuel Mode.

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

Despite improvements in internal combustion engine efficiency, fossil fuel reliance remains a challenge for sustainable energy. Syngas, a hydrogen-carbon monoxide mixture derived from gasification, offers a viable transition fuel due to its compatibility with existing combustion technologies and reduced emissions. However, its low ignition propensity necessitates high intake temperatures or pressure, which can be mitigated by diesel pilot injection in dual-fuel engines. 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 flow rates (100 to 160 L/min). Key metrics include ignition delay

El Younsi, Laila, Nelson-Gruel, Dominique

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

Items per page:

1 – 50 of 41751