Effects of Intake Pressure Difference on the Flow near Valve Seat in Diesel Engine Using Three Dimensional Computation

In this paper an extensive CFD simulation of a four-stroke diesel engine is done. The flow in the intake valve is calculated in the steady state condition and the flow in eight work statuses –four kinds of pressure differences are analyzed, with two kinds of valve rising degree researched .The aim of the work is to characterize the influence of the intake pressure difference of the intake port.As a conclusion we find that as the pressure difference increases, the discharge coefficient decreases. The analysis results of the three dimensional flow field of the intake port show that in the conditions of low pressure difference and big valve rising the vortex will appear. In addition, in different pressure differences, the ratio of the pressure drop in the same region is different.