Numerical Prediction of Fluid Motion in the Induction System and the Cylinder in Reciprocating Engines

This paper presents a multidimensional computer program for simulating fluid dynamics in reciprocating internal combustion engines. The numerical procedure uses a time-dependent implicit finite-difference approach in a general curvilinear coordinate system on a grid which may expand and contract with the motion of the intake valve and piston. In this program, special attention has been paid to take into account complex geometries : the computational domain includes the intake port and the cylinder, the motion and closure of the valve are described, the piston may contain a bowl.

The intake process followed by compression in two- and three-dimensional direct injection four stroke diesel engine configurations are simulated. The results show that the program is applicable to characterize flow structure simultaneously in the intake port and the cylinder.