Calculations of Steady Intake Flow in an Engine Using Unstructured Mesh.

Abstract

A calculation method for steady compressible flows using a solution adaptive unstructured mesh is proposed and it's applicability is demonstrated for two-dimensional and axisymmetric engine intake flows. The mesh is generated by the rule-based Delaunay triangulation method. The governing equations are discretized by the finite volume method. The second order accurate Roe's upwind scheme is used for the inviscid flux calculation. The viscous fluxes are calculated by the transformation to the local general coordinates. The utility of the adaptive unstructured mesh method is shown in the 2D engine intake flow calculations. The present method using a low Reynolds number k-c model is valid for the velocity profile in the turbulent boundary layer. The calculated discharge coefficients with valve lifts in an axisymmetric engine agree well with the measurements.