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Sustainable Aviation Fuels (SAFs) offer great promises towards decarbonizing the aviation sector. Due to the high safety standards and global scale of the aviation industry, SAFs pose challenges to aircraft engines and combustion processes, which must be thoroughly understood. Soot emissions from aircrafts play a crucial role, acting as ice nuclei and contributing to the formation of contrail cirrus clouds, which, in turn, may account for a substantial portion of the net radiative climate forcing. This study focuses on utilizing detailed kinetic simulations and soot modeling to investigate soot particle generation in aero-engines operating on SAFs. Differences in soot yield were investigated for different fuel components, including n-alkanes, iso-alkanes, cycloalkanes, and aromatics. A 0-D simulation framework was developed and utilized in conjunction with advanced soot models to predict and assess soot processes under conditions relevant to aero-engine combustion.

The combustion of hydrogen (H2) as a fuel is attractive due to its clean combustion or combustion-enhancing properties when used as a supplement to other fuels. However, the challenge of using H2 as a fuel for transportation applications is the difficulty of onboard storage. Cracking onboard stored ammonia (NH3) into H2 can also improve combustion performance and emissions in mobile applications fuelled with zero and carbon-neutral fuels. However, the reforming process is not always 100 % efficient which can lead to the presence of NH3 in the combustion process. The presence of NH3 can influence engine performance, combustion and emissions. Therefore, this experimental study reports the effect of H2 and H2/NH3/N2 fuel blends added to gasoline in a dual-fuel operation under both stoichiometric (λ=1.0) and lean-burn (λ>1.0) operating conditions in a spark ignition (SI) engine.

As part of the European Green Deal, the EU has set itself the binding target of achieving climate neutrality by 2050 with the European Climate Act. At the same time, the EU is currently being confronted with an unprecedented energy crisis coupled with an increasing economic pressure, caused by military conflicts and geopolitical tensions resulting in increased fossil fuel prices. However due to high energy density liquid hydro-carbons are still critical needed fuels for transportation. On the other hand Biomass wastes, like sewage sludge and paper sludge, are currently a significant challenge to environmental protection. As a result due to nitrate pollution in soil, e.g. sewage sludge is no longer permissible to distribute on agricultural fields in a growing number of areas such as parts of Italy and Germany. Therefore there is currently a growing move towards the use of sewage sludge or paper sludge in thermal conversion processes.

The Advanced Fuel Ignition Delay Analyzer (AFIDA) apparatus can measure the ignition delay times with high repeatability within very short time. The device also requires small quantities of fuel samples. During AFIDA experiments, liquid fuel is injected into a hot and constant-volume chamber at high pressure. This way the ignition of the spray combines the effects of realistic influences like liquid evaporation and combustion chemistry. The present work investigates the effects of blending ethanol and 2,5-dimethylfuran with primary reference fuels (i.e., mixtures of iso-octane and n-heptane). The primary motivation of this study is to show the differences in ignition delay times of different gasoline-ethanol and gasoline-2,5-dimethylfuran blends where both physical mixing and chemical kinetics have considerable influences. The primary reference fuel is considered as the gasoline surrogate in this work. The study has been conducted at a range of temperatures and pressures.

Hydrogen as a chemical energy carrier is considered as one of the most promising options to achieve effective decarbonization of the transportation sector, due to its carbon-free chemical composition. This is particularly true for applications that rely on internal combustion engines (ICEs), although much research is still needed to achieve stable, reliable, and safe operations of the engine. To this purpose, direct injection (DI) of gaseous hydrogen during the compression stroke offers great potential to avoid backfire and largely reduce preignition issues, as opposed to port-fuel injection. Recently, much research has been dedicated, both experimentally and numerically, to understanding the physics and chemistry connected with hydrogen’s mixing and combustion processes in ICEs. This work presents a computational fluid dynamics (CFD) study of the hydrogen DI process in an optical engine operating at relatively low tumble conditions.

The use of carbon-free fuels, such as ammonia or hydrogen, or at least carbon neutral fuels, such as green methane or methanol is one of the most important paths in the development of clean internal combustion engines (ICE). Especially for large, heavy-duty engines, this seems to be the most promising route, as replacing them with battery electric or fuel cell drives poses even greater challenges, at least for the time being. But for some applications or areas of the world, even small ICEs for trucks, passenger cars or off-road vehicles, operated with alternative fuels will still remain the mean of choice. One of the biggest challenges in the development of hydrogen combustion engines is achieving high compression ratios and mean effective pressures due to combustion anomalies, caused by the low ignition delay and broad flammability limit of hydrogen. Oil droplets are considered to be one of the main triggers for pre-ignition and knocking.

The population growth has led to a significant rise in car demand, raising pollution levels. It compelled governments to enact more stringent pollution standards. Researchers are exploring alternative fuels and advanced low-temperature combustion modes to meet the emission standards. The reactivity-controlled compression ignition strategy is one of the potential combustion strategies to reduce the particulate matter and NOx simultaneously while maintaining higher fuel conversion efficiency. This study investigated the influence of Diesel injection timing and premixing ratio on the cyclic variation of RCCI engines fueled with gasoline and butanol as low reactivity fuel. The experiments were carried out on the single-cylinder diesel engine modified to operate in RCCI mode. All the experiments were carried out at constant load and engine speed. A developmental ECU was used to regulate fuel mass and injection time.

In recent years, deposit formation in the fuel systems for heavy-duty engines, using drop-in fuels, have become increasingly common. Drop-in fuels are particularly appealing because as they are compatible with existing engines, allowing for higher proportions of alternative fuels to be blended with conventional fuels. However, the precipitation of insoluble substances from drop-in fuels can result in fuel filter clogging and the formation of internal injector deposits, leading to higher fuel consumption and issues with engine drivability. The precise reasons behind the formation of these deposits in the fuel system remain unclear, with factors such as operating conditions, fuel quality, and fuel contamination all suggested as potential contributors. In order to reproduce and study the formation of internal injector deposits, for heavy-duty engines under controlled conditions, facilitating a more precise comparison to field trials, a novel injector test rig has been developed.

Oxygenated substances are a promising approach in the field of alternative fuels. A current example of such a fuel are Polyoxymethylene Dimethyl Ethers (OME). With their physical and chemical properties, alternative fuels like OME pose new challenges for diesel engine injection systems. As the heating value is low compared to conventional Diesel fuel, measures must be taken to increase the amount of fuel injected. Possible solutions include increasing the nozzle hole diameter, the injection pressure, and the number of nozzle holes. All mentioned adaptions have an influence on the mixture formation and make it necessary to examine the injection process in detail also with regard to phenomena such as cavitation. In this study, three passenger car Diesel injector nozzles are compared, two of which are adapted in terms of nozzle hole diameter (increase by 20%) and number of nozzle holes (increase from 8 to 12) in order to increase the mass flow rate of fuel to the required elevated level.

Abstract Engine brakes are more effective in braking a heavy-duty vehicle during deceleration compared to the traditional clutch-brake system. Therefore, commercial vehicle OEM’s along with regulations, demand the acclimatizing of engine brake (EB) system. To achieve this, it is equally important to adopt to variable valve actuation dynamic valvetrain (VT) system. To help develop these systems, Model Based Product Development approach is used primarily at Eaton. In current work, the effect of valve lash sensitivity on EB performance and VT dynamics is studied using multi physics GT-SUITE models. This helps to understand the impact of lash on valve lift opening, lift loss and overall VT system compliance. In addition to above VT dynamics, its effect on EB power is also studied. This is done using a medium duty 6-cylinder GT-POWER engine model developed from Fast Response Model (FRM) database.

For the survival of internal combustion engines, the required research right now is for alternative fuels, including drop-ins. Certain types of alternative fuels have been estimated to confirm the superiority in thermal efficiency. In this study, using a single-cylinder engine, olefin and oxygenated fuels were evaluated as a drop-in fuel considering the fuel characteristic parameters. Furthermore, the effect of various additive fuels on combustion speed was expressed using universal characteristics parameters. In addition, the prediction of CO2 emission from passenger cars were carried out by changing the fuels. The CO2 emission in running WLTC was estimated using Modelica. As a result, it was found that the CO2 emission can be reduced by adding olefin and oxygenated fuels.

Because it can be produced in a green form, methanol is envisioned as a potential fuel to replace conventional diesel fuel and directly reduce the greenhouse gas (GHG) impact of maritime transportation. For these reasons, Original Equipment Manufacturers (OEMs) working on marine applications are focusing on making methanol easily usable in Compression Ignition (CI) engines. While it is an easy-to-use substance with manageable energy content, methanol has a few drawbacks, including a high latent heat of vaporization and a high auto-ignition temperature, all of which affect combustion quality. Therefore, solutions have been found or are still under study to give it Diesel-like behavior. One solution is to use a pilot fuel for ignition in significant quantities. A previous study conducted at the PRISME laboratory highlighted the possibility of using a Combustion Enhancer based on Nitrates (CEN) as an additive.

The objective of the project was to evaluate the energy efficiency of a hybrid electric tractor-semi-trailer combination prototype. The prototype was developed for log hauling application by integrating an existing tractor with an electric semi-trailer to improve fuel consumption and reduce greenhouse gas emissions. One of the conventional axles of the quad axle semi-trailer was replaced with a drive axle powered by an electric motor. Tests were conducted on a 105 km test route with a maximum difference in elevation of 355 m, including a hilly section with a length of 89 km. The results indicated fuel savings ranging from 10.5% to 14% per test run, with an average fuel savings of 12% when the electric drive axle was engaged. The hybrid electric tractor semi-trailer consumed 17.5% less fuel up-hill and 9.4% less down-hill. Throughout each test run, the battery’s state of charge fluctuated, averaging between 88% at the start and 52% at the end.

The automotive industry faces significant obstacles in its efforts to improve fuel economy and reduce carbon dioxide emissions. Current conventional automotive powertrain systems are approaching their technical limits and will not be able to meet future carbon dioxide emission targets as defined by the tank-to-wheel benchmark test. As automakers transition to low-carbon transportation solutions through electrification, there are significant challenges in managing energy and improving overall vehicle efficiency, particularly in real-world driving scenarios. While electrification offers a promising path to low-carbon transportation, it also presents significant challenges in terms of energy management and vehicle efficiency, particularly in real-world scenarios. Battery electric vehicles have a favorable tank-to-wheel balance but are constrained by limited range due to the low battery energy density inherent in their technology.

Original equipment manufacturers have already begun to transition their vehicles from traditional internal combustion engines (ICs) to electric drives (EVs). As the industry continues to move towards electrification, the entire industry, and especially Valeo, is focusing on lean product development (LPD) with the help of numerical simulation. Optimization techniques help industry achieve the most accurate product at the lowest cost without sacrificing performance. Generally gears are mainly used for power transmission in the advanced technologies of electric vehicles. There are many factors that must be taken into account when designing a gear transmission system. Finding the most appropriate design parameters for a gear transmission system can be a challenge, and optimization parameters will help to find the best compromise between them.

Rotor and Stator are the key constituents of an electric motor that are made of several laminates punched from a sheet metal and stacked together. The rotor stack is inserted with magnets at the punched-out pockets and is assembled with a shaft via press fitting. Rotor assembly being the rotating part of an E-Motor is subjected to centrifugal loads due to masses of magnets, lamination stack and shaft rotating at high speeds, temperatures and assembling loads because of which rotor laminates experience failures as the high strains develop in the regions on the laminate that support magnets. Typically, these high strain locations are the sections of the magnet pockets one on the outer diameter of the laminate and the other at the sections between the magnet pockets. Traditionally, these high strains are addressed by increasing the area of these sections, but this has a detrimental effect on the electromagnetic performance.

With the increasing pursuit of comfort in mobility, NVH characteristics are becoming more important than ever. Achieving a benchmark beating NVH behavior involves optimizing source, transfer paths as well as target location mechanical characteristics. In ICE vehicles, powertrain accounts for a major source of noise and vibration. This work encompasses NVH refinement strategies for a single-cylinder compression ignition engine. The work starts with setting target values for NVH characteristics based on competitive benchmark data analysis. A complete development strategy involving extensive testing and CAE correlation is presented here. Contribution analysis in the component level for optimization of NVH behavior is carried out by employing NVH testing in an anechoic chamber supported by CAE simulations.

The function of powertrain mounts is to securely anchor the engine and gearbox within a vehicle, effectively absorbing vibrations and shielding the vehicle's body from powertrain movements and road irregularities. Traditionally crafted from aluminum, sheet metal, or cast iron, there has been a notable transition towards employing fibre-reinforced polymer (FRP) as a viable alternative. This shift is motivated by the potential to reduce weight and cost, alongside enhancing noise, vibration, and harshness (NVH) characteristics. This study aims to evaluate the relative strengths of existing brackets compared to those made of FRP, with a focus on their modal response and crash resistance. Due to the absence of a standardized method for modelling orthotropic materials in powertrain mounting brackets, this paper proposes a systematic approach to address this gap.

In order to reduce the pumping loss of low loads and maximize the lean combustion advantage of hydrogen, the paper proposes a load control strategy based on hydrogen mass, called quality control, for improving thermal efficiency and emissions at low loads. The advantages of quality control and the effect of VVT on the combustion performance of hydrogen internal combustion engines under low loads were discussed. The results show that when the relative air–fuel ratio (λ) increases to more than 2.5, the NOx emissions are reduced to less than 3.5 g/kW · h at the brake mean effective pressure (BMEP) below 8 bar, especially when the BMEP is less than 5 bar, the NOx is within 0.2 g/kW · h. Compared to quantity control based on air mass, the quality control strategy based on hydrogen mass achieves over a 2.0% reduction in pumping loss at BMEP levels lower than 4.4 bar.

As the world looks to net-zero emissions goals, hybrid electric vehicles may play an increasingly important role. For passenger electric vehicles (EVs) that predominantly make short journeys but occasionally need to make longer trips, electrofuel range extension may be more cost effective than either hydrogen or rapid charging. Micro gas turbines and catalytic combustion show significant potential to deliver low-cost, low-maintenance, lightweight engines with virtually no emissions, and hydrocarbon consuming solid oxide fuel cells show even greater potential in these areas. Aditioanlly, sodium-ion batteries for EVs, dispatachable vehicle-to-grid power and buffering, and variable intermittent renewable energy could also play key roles. The Role of Hybrid Vehicles in a Net-zero Transport System explores the costs, considerations, and challenges facing these technologies. Click here to access the full SAE EDGETM Research Report portfolio.