Effect of Manifold Configuration in Turbulence inside the Cylinder of a Direct Injection Diesel Engine by Cfd Simulation

This paper discusses the predicted flow structure inside the cylinder with threedimensional modeling of incylinder flow field with 225 spiral port having three different entry angles (20,32.5 and 45) and at 3000 rpm. Swirl velocities and turbulence inside the cylinder during suction and compression stroke under motoring conditions have been compared. The turbulence is modeled using RNG k-ε model. Finally the comparison of volumetric efficiency of the engine with the different entry angles for an engine speed of 3000rpm is also presented. Before modeling the spiral port configurations, one normal production engine helical manifold was modeled for the validation of the STAR CD code. The predicted CFD results of mean swirl velocity of the engine at different locations inside the combustion chamber at the end of compression stroke have been compared with experimental results available in the literature [4]. The results obtained showed reasonably good agreement with the experimental data in the literature, which has given confidence to use the model for the development of new intake spiral manifold with different entry angles. It is observed that 225 spiral port with 20entry gives the maximum swirl ratio inside the cylinder.