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For the purpose of achieving carbon-neutrality in the mobility sector by 2050, hydrogen can play a crucial role as an alternative energy carrier, not only for direct usage in fuel cell-powered vehicles, but also for fueling internal combustion engines. This paper focuses on the numerical investigation of high-pressure hydrogen injection and the mixture formation inside a high-tumble engine with a conventional liquid fuel injector for passenger cars. Since the traditional 3D-CFD approach of simulating the inner flow of an injector requires a very high spatial and temporal resolution, the enormous computational effort, especially for full engine simulations, is a big challenge for an effective virtual development of modern engines. An alternative and more pragmatic lagrangian 3D-CFD approach offers opportunities for a significant reduction in computational effort without sacrificing reliability.

Abstract TOC

Testing of ducted fuel injection (DFI) in a single-cylinder engine with production-like hardware previously showed that adding a duct structure increased soot emissions at the full load, rated speed operating point [1]. The authors hypothesized that the DFI flame, which travels faster than a conventional diesel combustion (CDC) flame, and has a shorter distance to travel, was being re-entrained into the on-going fuel injection around the lift-off length (LOL), thus reducing air entrainment into the on-going injection. The engine operating condition and the engine combustion chamber geometry were duplicated in a constant pressure vessel. The experimental setup used a 3D piston section combined with a glass fire deck allowing for a comparison between a CDC flame and a DFI flame via high-speed imaging. CH* imaging of the 3D piston profile view clearly confirmed the re-entrainment hypothesis presented in the previous engine work.

The piston and piston ring are used in a severe contact environment in engine durability tests, which causes severe wear to the piston ring groove, leading to significant development costs for countermeasures. Conventionally, in order to ensure functional feasibility through wear on the piston top ring groove (hereinafter “ring groove”), only functional evaluations through actual engine durability testing were performed, and there was an issue in determining the limit value for the actual amount of wear itself. Because of this, the mechanism that may cause wear on the ring groove was clarified through past research, but this resulted in judgment criteria with some leeway from the perspective of functional assurance. To establish judgment criteria, it was necessary to understand both functional effect from ring groove wear and the mechanism behind it.

In the context of carbon neutrality, ammonia is considered a zero-carbon fuel with potential applications in the transportation sector. However, its high ignition energy, low flame speed, and high natural temperature, indicative of low reactivity, make it challenging to be applied as a sole fuel in engines. In such a scenario, the use of another zero-carbon and highly reactive fuel, hydrogen, becomes necessary to enhance the combustion of ammonia. Furthermore, jet ignition, a method known for improving engine combustion performance, may also hold potential for enhancing the combustion performance of ammonia engines. To explore the applicability of jet ignition in engines, this study conducted experimental research on a single-cylinder engine. Two ignition methods were employed: passive jet ignition of premixed ammonia-hydrogen at a compression ratio of 11.5, and active jet ignition of pure ammonia using hydrogen jet flame at a compression ratio of 17.3.

This work represents an advanced engineering research project partially funded by the U.S. Department of Energy (DOE). Ford Motor Company, FEV North America, and Oak Ridge National Laboratory collaborated to develop a next generation boosted spark ignited engine concept. The project goals, specified by the DOE, were 23% improved fuel economy and 15% reduced weight relative to a 2015 or newer light-duty vehicle. The fuel economy goal was achieved by designing an engine incorporating high geometric compression ratio, high dilution tolerance, low pumping work, and low friction. The increased tendency for knock with high compression ratio was addressed using early intake valve closing (EIVC), cooled exhaust gas recirculation (EGR), an active pre-chamber ignition system, and careful management of the fresh charge temperature.

The depletion of oil resource and change in global warming has led to the development of alternate energy resources. Commercially the LPG gas is used as alternate fuel for the spark ignition engine. In this work an experimental investigation is done on Liquefied Petroleum Gas (LPG) along with dual fuel mode of diesel as an alternative fuel for four stroke compression ignition engines. The primary objective of this study was to analyze the performance and the exhaust emissions of the engine using different LPG flow rate. The engine used in the study was originally a single cylinder, four-stroke compression ignition engine and minor modifications were carried out to permit the experiments to run on LPG fuel. The LPG is supplied in the suction stroke mixed with air while diesel is injected at the end of the compression stroke to initiate the combustion process. The LPG is made to flow with different levels of 3%, 6%, 9%, 12%, 18% and 21% on the volume basis with Diesel 100%.

Abstract Improving thermal efficiency of an internal combustion engine is one of the most cost-effective ways to reduce life cycle-based CO2 emissions for transportation. Lean burn technology has the potential to reach high thermal efficiency if simultaneous low NOx, HC, and CO emissions can be achieved. Low NOx can be realized by ultra-lean (λ ≥ 2) spark-ignited combustion; however, the HC and CO emissions can increase due to slow flame propagation and high combustion variability. In this work, we introduce a new combustion concept called turbulent jet-controlled compression ignition, which utilizes multiple turbulent jets to ignite the mixture and subsequently triggers end gas autoignition. As a result, the ultra-lean combustion is further improved with reduced late-cycle combustion duration and enhanced HC and CO oxidation. A low-cost passive prechamber is innovatively fueled using a DI injector in the main combustion chamber through spray-guided stratification.

With the increasing focus on reducing CO2 emissions to combat global warming and climate change, the automotive industry is exploring near zero-emission alternative fuels to replace traditional fossil-based fuels like diesel, gasoline, and CNG. Methanol is a promising alternative fuel that is being evaluated in India due to its easy transportation and storage, as well as its production scalability and availability potential. This study focuses on the retro-fitment solution of M100 (pure methanol) SI port-fuel injection (PFI) mode of combustion. A heavy duty single-cylinder engine test setup was used to assess methanol SI combustion characteristic. Lean operation strategy has been investigated. At lean mixture conditions a significant drop in NOX and CO emissions was achieved. The fuel injection techniques and the impact of exhaust gas recirculation (EGR) on the conventional stoichiometric combustion process is highlighted.

Researchers are under pressure to investigate and discover ways to improve the efficacy and reduce emissions from ICE due to the depletion of energy resources and the growing concern over global warming. Hydrogen is viewed as a promising fuel and has been investigated as a potential fuel in combustion because to several desirable qualities like carbon-less content and strong flammability limitations. When equated to other alternative fuels like LPG, CNG, LNG, etc., hydrogen has inimitable qualities because it lacks carbon, making it one of the promising alternatives fuels. In order to achieve zero CO2 emissions for traffic applications in the near future, hydrogen being an automotive fuel in ICE is a solution. The ICE powered by hydrogen is prepared for that. The actual drawbacks of using hydrogen in ICE generally are manufacturing, storage, and development of the requisite infrastructure. Hydrogen can be produced in its many forms.

Reducing vehicular noise has become a crucial step in product development to meet stringent legislation and improve passenger experience. Smaller vehicles like three-wheelers and compact cars are often powered by a single cylinder engine due to product cost, packaging and weight constraints. Unlike a multi-cylinder engine where cylinders fire one after another which helps to reduce noise levels by destructive interference of pressure waves, a single cylinder engine produces higher noise levels due to firing of a single cylinder. Intake and exhaust flow noise is one of the dominant sources of vehicular noise. This study focuses on using CAE tools to reduce intake and exhaust flow noise levels to meet target noise requirements. One dimensional (1-D) gas dynamics simulation provides a good trade-off between accuracy and run-time, allowing for evaluation of multiple design iterations with acceptable accuracy in a relatively short time frame.

Petroleum Oil, Lubricants (POL) & Liquefied petroleum gas (LPG) tanker vehicles are special application segment that holds a significant Market share for commercial vehicles. These vehicles need to comply additional Safety regulations specified by Petroleum and explosives safety organization (PESO). For compliance to Rule-70, Protective heat shield on exhaust system needs to be designed and validated in order to avoid any catastrophic failure. The paper demonstrates the methodology to identify the worst case scenario for the existing commercial vehicle segment. Based on detail digital mock up (DMU) review Metallic heat shield was designed on after treatment system (ATS). The flexible heat shield was designed for exhaust pipe & joints in order to restrain the heat flow to the surrounding aggregates. After finalising design, CFD analysis was carried out to find out the thermal effects on various components and results within acceptable limits.

Computational tools have become indispensable in the development of cam profiles, aiding designers in achieving optimal performance. This paper explores the application of computational tools in the design of cam profiles for a single-cylinder research engine (SCRE) prototype under development with a direct-acting mechanism. The primary objective is to present a comprehensive design process, encompassing kinematic analysis and Quasi-Dynamic Analysis (QDA), to enable designers to generate preliminary cam profiles based on design requirements. The VT-Design® software, a part of the GT-SUITE package, is employed for simulations in this study. Key design considerations, such as lift, velocity, and acceleration curves, are discussed, emphasizing the importance of maintaining continuity in the acceleration curve. The design process involves optimizing the acceleration curve to minimize negative acceleration and improve dynamic response.

Abstract Despite the growing prominence of electrified vehicles, internal combustion engines remain essential in future transportation. This study delves into passive pre-chamber jet ignition, a leading-edge combustion technology, offering a comprehensive visualization of its operation under varying load and dilution conditions in light-duty GDI engines. Our primary objectives are to gain fundamental insights into passive pre-chamber jet ignition and subsequent main combustion processes and evaluate their response to different load and dilution conditions. We conducted experimental investigations using a light-duty, optical, single-cylinder engine equipped with three passive pre-chamber designs featuring varying nozzle diameters. Optical diagnostic imaging and heat release analysis provided critical insights.

According to the Annual Energy Outlook 2022 (AEO2022) report, almost 30% of the transport sector will still use internal combustion engines (ICE) until 2050. The transportation sector has been actively seeking different methods to reduce the CO2 emissions footprint of fossil fuels. The use of lower carbon-intensity fuels such as Renewable Diesel (RD) can enable a pathway to decarbonize the transport industry. This suggests the need for experimental or advanced numerical studies of RD to gain an understanding of its combustion and emissions performance. This work presents a numerical modeling approach to study the combustion and emissions of RD. The numerical model utilized the development of a reduced chemical kinetic mechanism for RD’s fuel chemistry. The final reduced mechanism for RD consists of 139 species and 721 reactions, which significantly shortened the computational time from using the detailed mechanism.

It is a well-known fact that HCCI combustion offers the possibility of achieving high efficiency with low emissions, but with the challenges in combustion control and ability to adjust to changing environmental conditions. To resolve the aforementioned challenges, a pre-chamber induced homogeneous charge compression ignition (PC-HCCI) combustion mode was experimentally tested with aim of providing initial operating boundaries in terms of combustion stability and obtaining initial performance results. The single cylinder engine equipped with active pre-chamber and compression ratio (CR) of 17.5 was fueled by gasoline. The initial experiments were performed at the engine speed of 1600 rpm with intake air temperatures varied from 33°C to 100°C to verify the possibility of achieving the PC-HCCI combustion mode and to compare the achieved engine performance and emission results with both PCSI and pure HCCI combustion modes used as reference cases.

Several governments are increasing the blending mandate of renewable fuels to reduce the life-cycle greenhouse gas emissions of the road transport sector. Currently, ethanol is a prominent renewable fuel and is used in low-level blends, such as E10 (10 %v/v ethanol, 90 %v/v gasoline) in many parts of the world. However, the exact concentration of ethanol amongst other renewable fuel components in commercially available fuels can vary and is not known. To understand the impact of the renewable fuel content on the emissions from Euro 6d-TEMP emissions specification vehicles, this paper examines the real-driving emissions (RDE) from four 2020 to 2022 model-year vehicles run on E0 and E10 fuels. CO, CO2, NO, and NO2 were measured through a Portable Emissions Measuring System (PEMS).

The rapid development of the automobile industry has brought energy and environmental issues that scholars are increasingly concerning about. Improving efficiency and reducing emissions are currently two hot topics in the internal combustion engine industry. Direct water injection technology (DWI) can effectively reduce the cylinder temperature, which is due to the absorption of the heat by the injecting liquid water. In addition, lower temperature in the cylinder will reduce the formation of NO. In this paper, a CFD simulation of DWI application in a lean-burning single-cylinder engine with pre-chamber jet ignition was carried out. And the engine was experimentally tested for the simulation model validation. And then the effect of DWI strategy with different injecting water mass on the combustion and emissions characteristics are analyzed. Physically, injected water not only absorbs heat but also provides heat insulation.

Hydrogen has attracted attention as one of the key fuels for making internal combustion engines carbon neutral. However, the combustion characteristics of hydrogen differ greatly from those of conventionally used hydrocarbons. Therefore, in order to develop next-generation internal combustion engines that operate on hydrogen, it is first necessary to have a thorough understanding of the combustion characteristics of hydrogen. Engines that can take maximum advantage of those characteristics should be developed on the basis of that knowledge. Toward that end, the purpose of this study was to investigate the fundamental combustion characteristics of hydrogen in a test engine. This paper presents the results of an investigation of the effects on low-temperature oxidation reactions and autoignition when hydrogen was blended into dimethyl ether (DME) [1, 2], a gaseous hydrocarbon fuel.