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The development of new fuels for internal combustion engines requires further technical support by understanding the pollutant formation mechanism in various phases of combustion so that emissions can be minimized. This research will therefore utilize a bespoke in-cylinder sampling system to analyze the precursors of PAHs and particulates during bio-derived lactone combustion in a single-cylinder diesel engine. The sampling system was composed of a poppet-type in-cylinder sampling valve that displaced one of the engine intake valves and protruded into the combustion chamber beyond the flame quenching layer, and a Gas Chromatography Flame Ionization Detector (GC-FID) that examined the samples. The sampling valve was electromagnetically actuated, and its operation was referenced to the engine crank shaft encoder, allowing the valve to open at any Crank Angle Degree (CAD) within a timing resolution of 0.2 CAD.

A major challenge for auto industries is reducing NOx and other exhaust gas emissions to meet stringent Euro 7 emission regulations. A urea Selective Catalyst Reduction (SCR) after-treatment system (ATS) commonly uses upstream urea water injection to reduce NOx from the engine exhaust gas. The NOx emission conversion rate in ATSs is high for high exhaust gas temperatures but substantially low for temperatures below 200℃. This study aims to improve the NOx conversion rate using urea pulse injection in a mass-production 2.2 L diesel engine equipped with an SCR ATS operated under low exhaust gas temperature. The engine experimental results show that, under 200℃ exhaust temperature and 3.73x104 h-1 gross hourly space velocity (SV), the NOx conversion rate can be improved by 5% using 5-sec ON and 12-sec OFF (denoted as 5/12 s) urea pulse supply compared to the constant supply under time-averaged 1.0 urea equivalence ratio.

Selective catalytic reduction (SCR) technology is currently one of the most effective methods to reduce NOx emissions for engine. In order to cope with the energy crisis and environmental pollution problems, hydrogen engines have been widely studied in recent years. However, high NOx emissions under some working conditions still need to be further solved. NH3-SCR technology is considered to be the most promising hydrogen engine after-treatment device. This paper used Cu-SSZ-13, which is widely commercially available, as the research object, and explored the relationship between micron and nanoscale grain sizes through experimental methods such as BET, XRD, NH3-TPD, UV-vis-DRS and activity testing, the influence mechanism of micron-scale and nano-scale grain size on the morphology and properties of Cu-SSZ-13 catalyst was explored.

The gasoline particulate filter (GPF), represents a durable solution for particulate emissions control in light-duty gasoline-fueled vehicles. It is also seen as a viable technology in North America to meet the upcoming US EPA tailpipe emission regulation, the proposed “Multipollutant Rule for Model Year 2027”. The goal of this study was to track the evolution of tailpipe particulate emissions of a modern GTDI light duty vehicle under typical North American mileage accumulation; from a fresh state to 4000-mile, and finally to its full useful life of 150,000-miles. For this purpose, a production TWC + GPF after-treatment system was installed in place of the T3B85 TWC-only system. Chassis dyno emissions testing was performed at the pre-determined mileage points with on-road driving conducted for the necessary mileage accumulation.

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.

In today’s competitive automotive market, customers are now looking for system efficiency as one of the important design parameters of system performance along with durability and reliability. It is essential to ensure products are designed to utilize maximum input power and have better system efficiency. In automotives, transmission and axle systems are power transmitting elements from prime mover to wheels and are one of the main contributors to overall vehicle efficiency. Hence, predicting and assessing overall system efficiency of these aggregates is of paramount importance. System efficiency is driven by component power losses for various speeds and torques, which are arising out of component design parameters, complex interaction within system, operating conditions, lubrication, temperatures etc. To capture multi-physics of speed and torque dependent losses of automotive axle, multidisciplinary and integrated approach is proposed in this paper.

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.

Electric Drive Unit (EDU) is essential system in electric vehicles and one of the important features in EDU is the Park Lock mechanism. It ensures safety of vehicle in parked condition and prevents vehicle from rolling on grades by locking the transmission. When vehicle is on a grade and park lock is activated, a pawl and ratchet system gradually slows down the vehicle to the critical speed of engagement with a series of acute ratcheting events between rachet gear and pawl teeth before fully locking the axle output shaft. This phenomenon is crucial because high speed engagement damages the mechanism due to sudden loads while low speed engagement causes risk of vehicle roll. Ratcheting phenomenon of park lock mechanism is highly nonlinear, dynamic and depends on different factors like rachet and pawl profiles in contact, friction properties, spring loads, actuation mechanism etc.

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.

To gain high efficiencies and long lifetimes, polymer electrolyte membrane fuel cell systems require precise control of the relative humidity of the cathode supply air. This is usually accomplished with membrane humidifiers. These are passive components that use the humidity of the cathode exhaust air to humidify the supply air. Due to the passive design, controllability is achieved via a bypass. To avoid the use of humidity sensors, map-based control strategies are possible. Such map-based control requires deep insights into the humidifier behavior in all possible thermodynamic operating states, including various water loads. This paper focuses on typical operating conditions of heavy-duty application at high load, specifically on the occurrence of liquid water in the cathode exhaust stream, which has not been sufficiently investigated in the literature yet. In order to simulate these conditions, we built a test rig with an optically accessible single-channel set-up.

In the field of polymer electrolyte membrane fuel cells (PEMFC), significant research has focused on the membrane electrode assembly (MEA) and electrochemical characterization methods. For real applications optimizing the fuel cell system (FCS) design is essential, requiring careful monitoring of electrochemical and thermodynamic process parameters such as pressure, temperature, relative humidity, heat flux, and gas composition. These operating conditions, provided by balance of plant (BoP) components, significantly impact FCS efficiency, especially relative humidity, which demands high energy input. The first step in a system development involves comprehensively characterizing the MEA by mapping a wide range of operating parameters, not just peak performance points, which are not necessarily the most beneficial for the FCS. This requires precise and dynamic adjustments of process parameters during testing to capture all relevant data efficiently.