Numerical Prediction of The Gas Flows in a Reciprocating Engine Cylinder during Intake Stoke (1st Report: Inviscid Flow).(Dept.M)

This paper presents a method for predicting the in-cylinder gas flows during the intake stroke of four-stroke engines. A simplified engine model with a deep-bowl piston configuration, and a central intake valve was used. An inviscid two-dimensional axisymmetric flow was investigated. The model used a finite difference procedure with an expanding/contracting grid in axisymmetric representation. The major source of troubles for the convergence of the solution was the unsteady turbulent jet flow issuing from the intake valve which required very small time intervals for the solution compared with that during the compression stroke where there is no jet flow exists. Results show a complicated flow field during the intake stroke in engine like-geometries.