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Many efforts have been invested to improve the fuel efficiency of vehicles mainly for the local consumers. One of the main techniques to have better fuel efficiency is cylinder deactivation system. In this paper, the main research area is focus on the investigation of cylinder deactivation (CDA) technology on common engine part load conditions within common Malaysian driving condition. CDA mostly being applied on multi cylinders engines. It has the advantage in improving fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6 liter four cylinders gasoline engine is studied. One-dimensional (1-D) engine modeling is performed to investigate the effect of intake and exhaust valve strategy on engine performance with CDA. The 1-D engine model is constructed starts from the air-box cleaner up to exhaust system according to the 1.6 liter actual engine geometries. The model is simulated at various engine speeds with full load condition.

This paper focuses on the possibility of enhancing the atomization process by testing several type of needle for the pressure-swirl gasoline direct injector. Under similar operating condition, three types of needle geometry with two different swirl intensities were investigated within fuel-air pressure differential from 3.0 to 10.0 MPa with 0.5 MPa step size. Using a commercial computational fluid dynamics (CFD) codes, the liquid sheet thickness at nozzle exit, and initial spray cone angle of the injection were calculated by means of 2D-axisymmetric swirl technique using multiphase Eulerian approach. A swirl-dominated RNG k-ε viscous model was applied. The calculated liquid sheet thicknesses were compared with an empirical correlation. The results of the CFD calculation were used to determine the theoretical Sauter Mean Diameter (SMD) droplet size using another correlation found from previous experimental work.