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The objective of the current research was to predict and analyze the flow through the grill of air intake system which is positioned behind the front wheel arch of vehicle. Most of the vehicle used today locates the grill of air intake at the front side so to acquire benefit of ram effect. In some cases, however, the grill is located behind the vehicle to improve wading performance. The geometry of air intake system of Land Rover Freelander was used in the modelling approach. The study was focused on different flow speeds on the grill at high load operation where the air speed at the grill side is high and creates negative pressure. The CFD results are validated against experimental data of steady flow test bench.

The paper presents analysis of performance and emission characteristics of a common rail diesel engine operating with RME, with and without EGR. In both cases, the RME fuel was pre-heated in a heat exchanger to control its temperature before being pumped to the common rail. The studied parameters include the in-cylinder pressure history, rate of heat release, mass fraction burned, and exhaust emissions. The results show that when the fuel temperature increases and the engine is operated without EGR, the brake specific fuel consumption (bsfc) decreases, engine efficiency increases and NOx emission slightly decreases. However, when EGR is used while fuel temperature is increased, the bsfc and engine efficiency is independent of fuel temperature while NOx slightly increases.

Multiple fuel injections with higher injection pressure are a way to improve diesel engine performance and lower emissions of unburned HCs, smoke, particulate matter and carbon monoxide (CO). However this method leads to a higher level of NOx emissions. A combination of higher pressure split injection and exhaust gas recirculation (EGR) has potential in controlling NOx emissions and engine performance simultaneously. The focus of this study is to investigate the effect of variation in injection pressure with split (pilot and main) injection, (with and without cooled EGR) on engine performance and emissions. The engine used is a common rail direct injection V6 Diesel fitted with turbo-charged variable turbine geometry (VTG) turbochargers, fuelled with ultra low sulphur diesel (ULSD).