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In the automotive field, reducing harmful pollutant, CO2 emissions and fuel consumption of vehicles while increasing customer comfort is a continuous challenge that requires more and more sophisticated technology implementations. However, it is often difficult to anticipate the advantages and drawbacks of a technology without having its prototype parts and/or knowing the optimal control strategy. In order to meet these challenges, the authors have developed a vehicle thermal model in AMESim platform to evaluate the benefits of an Active Grille Shutter (AGS) on fuel economy when applied. The vehicle model was based on a C-Segment vehicle powered by a 1.4L Diesel engine. The complete oil and coolant circuits were modeled as well as a friction model based on engine coolant and oil temperature.

A rapid compression/expansion machine (RCEM) based on a single-cylinder engine was developed to understand the fundamental phenomenon of knock during spark-ignition (SI) combustion. In order to cause auto-ignition in the end-gas mixture during the flame-propagation process, and also to visualize the processes, the original head of the engine was replaced with a specially designed combustion chamber. The effects of spark timing, compression ratio and equivalence ratio on knock intensity were systematically investigated using the RCEM with n-butane fuel. In addition, the possibility of knock control by the injection of hydrogen into the end-gas region is also discussed. The experimental results indicate that a higher compression ratio, spark-ignition timing at -10 °ATDC and a stoichiometric equivalence ratio cause heavy knock. However, the knock intensity is drastically decreased with hydrogen injection.

Utilization of ethanol-diesel blend fuels in partial Premixed Charge Compression Ignition (PCCI) combustion was attempted to achieve clean diesel engine. The experiment was carried out using a naturally aspirated single cylinder DI diesel engine equipped with common rail injection and cooled EGR systems. PCCI combustion was realized by two stage injection in which part of fuel was injected during the compression stroke and the rest near TDC. The results indicate that under middle to high engine loads, both weak sooting tendency and low cetane number of ethanol blend fuels offer a great improvement in PM and NOx emissions when compared to the diesel combustion with ordinary pilot injection. However, this results in penalties in thermal efficiency, THC and CO emissions.

Utilizing the desirable feature of hydrogen, this study demonstrates the improvement of engine performance and exhaust emissions due to the mixing of hydrogen into natural-gas fuel in a spark-ignition engine at the wide-open throttle (WOT) condition. Both hydrogen and natural-gas fuels were injected into the intake port only in the suction flow, which could make the operation under a wide range of conditions without backfire even at a hydrogen fuel. Based on the measured processes of combustion, the knock characteristics were discussed with special attention to the extremely high burning velocity of hydrogen. At a higher compression ratio, the thermal efficiency in the stoichiometric condition was improved, nevertheless a precise control of ignition timing was required to suppress a hard knock. From the experimental results of engine performance in a variety of parameters, optimal use of hydrogen was exhibited for different engine loads.