NUMERICAL PREDICTION OF GAS FLOW IN THE INTAKE PORTS OF FOUR-CYCLE INTERNAL COMBUSTION ENGINES (1ST REPORT, METHOD OF NUMERICAL ANALYSIS).

This paper describes a method for estimating the induction swirl intensity by means of numerical simulation of the gas flow in the intake ports of four-cycle engines. Three-dimensional flow of compressible viscous gas in the intake port has been calculated for intake stroke in order to predict the effect of the configuration of the intake port, especially the configuration of the helical port, on the induction swirl intensity. Cartesian grids are used to simulate the unsteady flow field in the model passage of the intake port. The results show that the present method is applicable to investigate the flow in the intake ports, and also that the volumetric efficiency and induction swirl intensity can be estimated from the distribution of the calculated outflow velocity around the intake valve.