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The use of renewable fuels in place of conventional hydrocarbon fuels can minimize the carbon footprint of internal combustion engines. DME has been treated as a suitable surrogate to diesel fuel because of its high reactivity and soot-less combustion characteristics. The lower energy density of DME fuel demands a higher fuel supply rate to match the engine loads compared to diesel, which was achieved through prolonged injection duration and larger nozzle holes. When used as a pilot fuel to control the combustion behavior in a dual-fuel application, the fuel energy delivery rate becomes less critical allowing the use of a standard diesel common-rail injector for DME direct injection. In this work, the combustion of DME-Ethanol dual-fuel reactivity-controlled compression ignition was experimentally investigated.

A linerless aluminum (Al) engine block has potential to reduce the weight of an automotive engine and improve the fuel economy. However, the Al cylinder surface of an aluminum engine block is not usually strong enough to withstand the sliding wear against piston rings. A few surface processing technologies are used to protect the surface of cylinders. Among them, a thermal spraying coating, such as plasma transferred wire arc (PTWA) is already popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum-silicon (Al-Si) alloys and reducing the friction between the cylinder and piston. In this work, two different PEO coatings with a thickness of around 23 μm were prepared on an Al-Si alloy A356, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coatings at oil lubricant conditions. A cast iron sample was also used to do similar tribological tests for comparison.

The use of low temperature combustion (LTC) in diesel engines tends to suppress the NOx and dry soot emissions from diesel engines. However, due to the limitations of conventional diesel fuel properties, such as the high reactivity and low volatility, implementation of LTC is highly dependent on the application of exhaust gas recirculation (EGR). While the replacement of some of the fresh air intake with the burnt exhaust gas using EGR prevents premature combustion, it also results in a reduction in thermal efficiency. In this work, the use of two different alcohol fuels, ethanol and butanol, in a high compression ratio diesel engine has been investigated to examine their potential as substitutes for conventional diesel fuel when operating under low temperature combustion mode. The effect of diesel injection timing, alcohol fuel ratios, and EGR on engine emissions and efficiency were studied at indicated mean effective pressures in the range 0.8 to 1.2 MPa.

This research focuses on study of feasibility of using ceramic oxide coatings on the cylinder wall of hypoeutectic aluminum silicon alloy engine blocks. Coatings are achieved in an aqueous electrolytic bath and composed of both alpha and gamma phases of Al2O3 and have shown promising wear resistance. Composition and acidity level of the electrolyte creates a variation of surface roughness, coating hardness and thickness which has direct influence on the wear behavior of the sliding surfaces. The effect of load bearing and coating morphology on coefficient of friction was studied. SEM images of the substrate showed no predominant wear behavior or delamination. Coefficient of friction and wear rate were also measured. This study shows the importance of surface structure on oil retention and wear rate. Coarser coatings can be desirable under starved oil condition since they show lower coefficient of friction.

Recently, joining of cast aluminum components with wrought and/or cast similar metals becomes an urgent task for the auto industry to develop light-weight complex and large-scale chassis and body structures for further reduction in vehicle weight. In this study, fusion-joining of vacuum high pressure die cast (VHPDC) alloy A356 subjected to T5 heat treatment and wrought alloy 6061 with the Gas Metal Arc Welding (GMAW-MIG) process was experimented in an effort to understand the effect of the MIG process on the microstructure development and tensile behaviors of the base alloys (T5 A356 and 6061), Heat Affected Zone (HAZ) and Fusion Zone (filler metal ER4043). The results of tensile testing indicated that the ultimate tensile strength (UTS), yield strength (YS) and elongation (Ef) of VHPDC T5 A356 were relatively high, compared to both wrought alloy 6061 and the filler metal (ER 4043).

Low temperature combustion (LTC) in diesel engines can be enabled using a multitude of fuel injection strategies, coupled with the elevated use of exhaust gas recirculation and intake boost. The common modes of LTC include the single-injection LTC with heavy EGR and the homogeneous charge compression ignition (HCCI), implemented with multiple early-injections during the compression stroke. Previous research indicates that the single-injection LTC is more suitable at low engine loads while the HCCI combustion can be targeted towards mid-load operation. To extend the load range of the LTC cycles, there is an urgent need to enable switching on-the-fly between the two combustion modes. The mode-switching is complicated by the fact that the challenges of enabling and ensuring stable engine operation under these two LTC modes are notably different.

The detailed flow, combustion process and emissions are studied within a In-Direct Injection (IDI) type diesel engine fueled with isooctane using a three-dimensional CFD code known as integrated CKL (CHEMKIN-KIVA-LES) solver that has been successfully developed by the authors to capture the details of turbulence flow structures and chemical kinetics. This CKL solver features three-dimensional turbulent two-phase flow and combustion with one equation k-Δ Large Eddy Simulation (LES) model for turbulence and CHEMKIN for chemical kinetics. The CKL solver was validated using the experimental data from modified KUBOTA D905 IDI type diesel engine converted to HCCI engine. Then the CKL solver is employed to study the effect of fuel injection strategies on the HCCI engine combustion process.

Al383/SiO₂ metal matrix composites (MMC) were designed to increase the wear properties of the Al alloy. However, the soft Al matrix was subject to large plastic deformation under high normal load during lubricated sliding wear tests, causing detachment of the reinforced particles. To further increase the wear resistance of the MMC, in this research, Plasma Electrolytic Oxidation (PEO) process was used to form oxide coatings on the MMC. The hard and wear-resistant oxide coatings protected the metal matrix during the wear tests, reducing the wear rate of MMC. The effect of both oxide coating thickness and volume content of SiO₂ particles on the wear behavior of MMC was investigated. It was found that with a proper combination of the volume content of SiO₂ and coating thickness, the MMC exhibited high wear resistance and low friction coefficient.

Diesel engines operating in the low-temperature combustion (LTC) mode generally tend to produce very low levels of NOx and soot. However, the implementation of LTC is challenged by the higher cycle-to-cycle variation with heavy EGR operation and the narrower operating corridors. Small variations in the intake charge dilution can significantly increase the unburnt hydrocarbon and carbon monoxide emissions as well as escalate the consecutive cyclic fluctuations of the cylinder charge. This in turn adversely affects the robustness and efficiency of the LTC operation. However, Improvements in the promptness and accuracy of combustion control as well as tightened control on the intake oxygen concentration can enhance the robustness and efficiency of the LTC operation in diesel engines. In this work, a set of field programmable gate array (FPGA) modules were coded and interlaced to suffice on-the-fly combustion event modulations on a cycle-by-cycle basis.

In the past decade, magnesium (aluminum) alloy use in the automotive industry has increased in order to reduce vehicle weight and fuel consumption. However, their applications are usually limited to temperatures of up to 120°C. Improvements in the high-temperature mechanical properties of magnesium alloys would greatly expand their industrial applications. As compared to the unreinforced monolithic metal, metal matrix composites have been recognized to possess superior mechanical properties, such as high elastic modulus and strengths as well as enhanced wear resistance. In this study, a novel approach of making hybrid preforms with two or more types reinforcements, i.e., different size particles and fibers, for magnesium-based composites was developed. An advanced and affordable technique of fabricating hybrid magnesium-based composites called the preform-squeeze casting was employed successfully.

The HCCI combustion mode features characteristics that uniquely position it to facilitate the convergence of gasoline and diesel engine technologies. The ability of HCCI combustion to accommodate a broad variety of fuels is one such characteristic. In this work the viability of a simulated biomass gas that resembles in its composition so-called producer gas is investigated. The paper reports on a single-cylinder HCCI engine's indicated performance when fuelled with the biomass derived gaseous fuels. There were two biomass gas fuel compositions used in this study. Both compositions contained the same amount of CH₄, CO₂, and N₂, and they differed by the H₂ to CO ratio; for Composition 1 the ratio was 10% to 25%, and for Composition 2 it was 15% to 20%. The indicated performance of the HCCI engine was evaluated based on in-cylinder cycle-resolved pressure measurements.

Exhaust Gas Recirculation (EGR) valves have been used in diesel engine operation to reduce NOx emissions. In EGR valve operation, the amount of exhaust gas re-circulating back into the intake manifold is controlled through the open position of the valve plate to keep the combustion temperature lower for NOx emission reduction. Different methods have been proposed to control the EGR valve. However, most of the approaches do not have the desired accuracy and the response time, which is critical for the after-treatment performance in low temperature diesel combustion. In this paper, the model of a motor driven EGR valve is first identified through experiments and then the Generalized Predictive Control (GPC) method which is an effective Model Predictive Control (MPC) method is applied to control the plate position of the valve.