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Alumina (Al2O3) thin film coatings are applied on Al alloys using Plasma Electrolytic Oxidation (PEO) method to reduce the wear and corrosion problems. Plasma Electrolytic Aluminating (PEA) is a technique which could generate Alumina coatings on cast iron, mild steel and copper alloys. In this study, the aim is to explore the anti-wear and anti-corrosion behaviours of PEA Alumina coatings on gray cast iron. The dry sliding tribology test data was obtained from Pin-on-Disk (POD) tests against SAE 52100 steel and Tungsten Carbide (WC) counterfaces. Comparing with the PEO Alumina coatings, the PEA Alumina coating has much lower Coefficient of Friction (COF) and less wear. The microstructure, chemical composition and phase composition of this coating were investigated with Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDX) and X-Ray Diffraction (XRD), respectively. There was FeO (or FeAl2O4) found on the PEA Alumina coating.

Gray cast iron brake rotor experiences substantial wear during braking and contributes largely to the wear debris emissions. Surface coating on the gray cast iron rotor represents a trending approach dealing with the problems. In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. Three different types of brake pads (ceramic, semi-metallic and non asbestos organic (NAO)) were used for tribotests. Performances of PEA coatings vs. different brake pad materials were comparatively investigated with respect to their coefficients of friction (COFs) and wear. The PEA-coated brake rotor has a dimple-like surface which promotes the formation of a thin transferred film to protect the rotor from wear. The transferred film materials come from the wear debris of the pads. The secondary plateaus are regenerated on the brake pads through compacting wear debris of the pads.

The transient characteristics of combustion and emissions during the engine start up at different higher cranking speeds for hybrid electric vehicle (HEV) applications were presented in this paper. Cycle-by-cycle analysis was done for each start up case. Intake air mass during the first several cycles decrease as the engine was cranked at higher speed. Ignition timing is delayed with higher cranking speed, which leads to an increase of exhaust temperature. For various start up cases, similar quantity of fuel is injected at the first cycle, but the ignition timing is significantly delayed to meet the acceleration requirement when cranking speed enhanced. Because of the deterioration of intake charge, the air-fuel mixture is over-enriched in the first several cycles for the cases at higher cranking speed. With cranking speed is increased, the in-cylinder residual gas fraction rises, which leads to poor combustion and decrease of mass fraction of burned fuel.

To improve the cold start performance and to reduce the misfire occurrence at cold start, the start-up strategy of total stoichiometric ratio combined with local rich mixture was applied in the study. The effect of injection strategy (the 1st injection timing, 2nd injection timing, 1st and 2nd fuel injection proportion and ignition timing) on the cold start HC emissions in the initial 10 cycles were investigated in a Two stage direct injection (TSDI) gasoline engine. The transient HC and NO emissions in the initial 10 cycles were analyzed, when the fuels are injected in the only 1st cycle and in the followed all cycles. The transient misfiring HC emissions were compared between the single and two-stage injection modes. In addition, the unburned HC (UBHC) emissions in the 1st cycle are compared among the TSDI engine, Gasoline direct injection (GDI) engine, Port fuel injection (PFI) engine and Liquefied petroleum gaseous (LPG) engine at the stoichiometric ratio.

Modern diesel engines employ a multitude of strategies for oxides of nitrogen (NOx) emission abatement, with exhaust gas recirculation (EGR) being one of the most effective technique. The need for a precise control on the intake charge dilution (as a result of EGR) is paramount since small fluctuations in the intake charge dilution at high EGR rates may cause larger than acceptable spikes in NOx/soot emissions or deterioration in the combustion efficiency, especially at low to mid-engine loads. The control problem becomes more pronounced during transient engine operation; currently the trend is to momentarily close the EGR valve during tip-in or tip-out events. Therefore, there is a need to understand the transient EGR behaviour and its impact on the intake charge development especially under unstable combustion regimes such as low temperature combustion.

The Argon Power Cycle engine is a novel concept for high efficiency and zero emission through the replacement of N2 by Ar. However, the higher in-cylinder temperature and pressure as by-products cause heavier knock. The anti-knock strategies, such as reducing compression ratio and retarding ignition time, offset the efficiency increased by the Argon Power Cycle. Therefore, knock control becomes the most urgent task for the Argon Power Cycle engine development. The anti-knock methods, including fuel replacement, ultra-lean combustion, high dilution combustion, and water injection, were considered. The simulated ignition delay times were used to evaluate the probability of knock. The Otto cycle, combined with chemical equilibrium, was utilized to confirm the effect on the thermal conversion efficiency and each in-cylinder thermodynamic state parameter. The results show that the ignition delay times increase by a factor of two when the Ar dilution ratio increases from 79% to 95%.

The exhaust aftertreatment strategy is one of the most fundamental aspects of spark ignition engine technologies. For various types of engines (e.g., carburetor engine, PFI engine and GDI engine), measuring, purifying, modeling, and control strategies regarding the exhaust aftertreatment systems vary significantly. The primary goal of exhaust aftetreatment systems is to reduce the exhaust emission levels of NOx, HC and CO as well as to lower combustion soot. In general, there is a tradeoff among different engine performance aspects. The exhaust catalytic systems, such as the three way catalyst (TWC) and lean NOx trap (LNT) converters, can be applied together with the development of other engine technologies (e.g., variable valve timing, cold start). With respect to engine soot, some advanced diagnosing techniques are essential to obtain thorough investigation of exhaust emission mechanisms.

The objective of this work was to investigate the potential of the electrostatic atomization for its application in internal combustion engines. In this paper, a theoretical model for secondary breakup of charged droplets was established. The electric force reduces the surface tension of liquid, whereby atomization is promoted. To improve the diesel droplet atomization remarkably by means of electrostatic charge, the charge-mass ratio should be at least at the order of 10-6C/g. In the interest of the practical application conditions in internal combustion engines, the high-pressure injected electrospray was generated and investigated under various injection pressures and electric conditions. By means of the Photron high-speed camera, the special features of electrospray were observed. The micro-characters including the drop size distribution and the variance of the drop diameter in the spray front area were investigated.

In this paper, a case study of Shanghai HEVs application and its effects on the social and environmental benefits are presented based on the multi views on the different aspects, such as, not only for the fuel consumption saving, but also emissions reduction and health effect, agriculture loss and cleaning cost. The results show that the potential benefits for the society from HEVs application are markedly with the increase of the ratio of HEV in the population of vehicle. Based on this, the policy to promote the HEV purchased by consumers is very important at the beginning of HEV into market.

REEV (Range-Extended Electric Vehicle) can avoid the mileage anxiety of BEV (Battery Electric Vehicle). Nevertheless, RE (Range Extender) for passenger cars prefers to use ICE (Internal Combustion Engine) with smaller displacement and lower cylinder number, which is usually with a worse vibration performance at low speeds. As RE only outputs electricity, it provides the possibility to optimize NVH (Noise, Vibration, and Harshness) of the engine by PMSM (Permanent Magnet Synchronous Motor). By real-time control, the electromagnetic torque of PMSM can track the shaft torque fluctuation during engine strokes, especially the combustion stroke. When the instability and rolling torque of RE could be suppressed, NVH performance of RE can be improved. This paper presents simulation research on speed fluctuation suppression for RE engine based on dynamic torque compensation by controlling a PMSM.

Research studies have suggested that changes to the ignition system are required to generate a more robust flame kernel in order to secure the ignition process for the future advanced high efficiency spark-ignition (SI) engines. In a typical inductive ignition system, the spark discharge is initiated by a transient high-power electrical breakdown and sustained by a relatively low-power glow process. The electrical breakdown is characterized as a capacitive discharge process with a small quantity of energy coming mainly from the gap parasitic capacitor. Enhancement of the breakdown is a potential avenue effectively for extending the lean limit of SI engine. In this work, the effect of high-power capacitive spark discharge on the early flame kernel growth of premixed methane-air mixtures is investigated through electrical probing and optical diagnosis.

The first firing cycle is very important for cold-start. Misfire of the first firing cycle can lead to significant HC emissions and affect the subsequent cycles. The first firing cycle for Gasoline SI engine have been reported in many studies. Liquefied petroleum gas (LPG) as an alternative fuel has been widely used in commercial vehicles during the last decade. However, the properties of the first firing cycle for LPG SI engine have been seldom reported. This paper presents an investigation of the characteristics of transient HC emissions of the first firing cycle during cold start on a LPG SI engine. A fast-response flame ionization detector (FFID) was applied to measure transient HC emissions of the first firing cycle in the exhaust port of the engine. At the same time, the transient cylinder pressure and instantaneous crankshaft speed of the engine were measured and recorded.

No two battery cells can be identical. Charging/discharging a battery pack without monitoring cell voltages or SoC (State-of-Charge) will cause cell voltages to deviate over time and the packs useable capacity to decrease quickly. To redistribute charge uniformly among cells, various cell balancing methods have been proposed in the literature. In this paper, a cell balancing method based on a single switched-capacitor is presented from a brand new perspective. Unlike the traditional balancing methods that rely on the voltage divergence criterion, this paper uses the SoC divergence criterion to shuttle charge from a highly charged cell to a poorly charged cell. Moreover, an equivalent resistance of the single-switched capacitor topology is derived in steady state. For fast cell balancing, design guidelines are provided for selecting a proper switching-time period and the capacitor parameters. Ultracapacitors are recommended to achieve this goal.

In order to reduce the weight of an automotive engine, an aluminum (Al) alloy engine block with cast iron liner has been successfully used to replace the gray cast iron engine. For newly emerging Al linerless engine in which the low surface hardness of the aluminum alloy has to be overcome, a few surface processing technologies are used to protect the surface of cylinders. Among them, plasma transferred wire arc (PTWA) thermal spraying coating is becoming popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum alloy and reducing the friction between the cylinder and piston. In this work, a PEO coating with a thickness of ∼20 μm was prepared, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coating at oil lubricant conditions. Different surface roughness of the coating and a large range of the sliding speeds were employed for the tests.

This research was concerned with the use of Exhaust Gas Recirculation (EGR) improving the fuel economy over a wide operating range in a downsized boosted gasoline engine. The experiments were performed in a 1.3-Litre turbocharged PFI gasoline engine, equipped with a Low Pressure (LP) water-cooled EGR system. The operating conditions varied from 1500rpm to 4000rpm and BMEP from 2bar to 17bar. Meanwhile, the engine’s typical operating points in NEDC cycle were tested separately. The compression ratio was also changed from 9.5 to 10.5 to pursue a higher thermal efficiency. A pre-compressor throttle was used in the experiment working together with the EGR loop to keep enough EGR rate over a large area of the engine speed and load map. The results indicated that, combined with a higher compression ratio, the LP-EGR could help to reduce the BSFC by 9∼12% at high-load region and 3∼5% at low-load region.

A hot exhaust gas burner system is applied to break through the limitations of the traditional diesel engine bench. Sufficient atomization is needed to realize spark ignition in a low-pressure burner system. Hence, the design of the atomization system is studied both experimentally and numerically. Through the reasonable optimization of the nozzle diameter, the air assist pressure, the angle among the four nozzles of four V-structures as well as the diameter and the angle of co-flow holes, an even distribution of small diesel droplets in the ignition area of the burner is realized. Consequently, diesel spray can be spark ignited in a low-pressure burner system, which can simulate the diesel exhaust. And the DPF can be installed downstream of the burner to quickly analyze the effect of ash accumulation on the DPF.

A novel reciprocating engine version of oxy-fuel combustion cycle combined with water direct injection (known as internal combustion rankine cycle) is presented in this paper. Water is injected near top dead center to control the reaction rate of the oxy-fuel mixture, as well as the peak in-cylinder temperature. The evaporation of the water mist will increase the mass of working gas inside the cylinder, and enhances the thermo efficiency and MEP. Moreover, the injected water is heated up through heat exchangers by both engine coolant and exhaust gas, and the waste heat is effectively recovered this way. This study investigates the combustion and emission characteristics of ICRC under different engine loads based on a single-cylinder, air-cooled SI engine fueled with propane. An extra diesel injector is employed to inject water with high injection temperature (160°C).

The present work proposed to implement oxy-fuel combustion mode into a homogeneous charge compression ignition engine to reduce complexity in engine emissions after-treatment and lower carbon dioxide emission. The combination of oxy-fuel combustion mode with homogeneous charge compression ignition engine can be further optimized by the utilization of direct high temperature and pressure water injection to improve cycle performance. A retrofitted conventional diesel engine coupled with port fuel injection and direct water injection is utilized in this study. A self-designed oxygen and carbon dioxide mixture intake system with flexible oxygen fraction adjustment ability is implemented in the test bench to simulate the adoption of exhaust gas recirculation. Water injection system is directly installed in the combustion chamber with a modified high speed solenoid diesel injector.

In this work, an innovative piston bowl design that physically divides the combustion chamber into a central zone and a peripheral zone is employed to assist the control of the ethanol-diesel combustion process via heat release shaping. The spatial combustion zone partition divides the premixed ethanol-air mixture into two portions, and the combustion event (timing and extent) of each portion can be controlled by the temporal diesel injection scheduling. As a result, the heat release profile of ethanol-diesel dual-fuel combustion is properly shaped to avoid excessive pressure rise rates and thus to improve the engine performance. The investigation is carried out through theoretical simulation study and empirical engine tests. Parametric simulation is first performed to evaluate the effects of heat release shaping on combustion noise and engine efficiency and to provide boundary conditions for subsequent engine tests.

Internal combustion Rankine cycle (ICRC) engine uses oxygen instead of air as oxidant during the combustion process, therefore totally eliminates the emission of NOx. CO2 could be captured after separated from the exhaust gas, the latter are mainly water vapor and CO2, through condensation at a relatively low price, and thus an ultra-low emission working cycle is achieved. Moreover, water is heated up by exhaust gas and injected into the cylinder during the combustion process to control combustion temperature, and evaporation of the water mist would increase working fluid inside the cylinder, therefore enhance indicated thermal efficiency. This study investigates the combustion characteristics of a quasi ICRC on a single-cylinder SI engine fueled with propane. Gas mixture of O2/CO2 is employed to simulate EGR in order to control in-cylinder temperature.