STUDY OF AIR MOTION IN RECIPROCATING ENGINE USING AN ALGEBRAIC GRID GENERATION TECHNIQUE

Abstract

An algorithm for a multidimensional numerical solution is developed that predicts axisym-metric two-dimensional in-cylinder flows on the boundaries of curved wall cylinder heads. Three types of cylinder heads are considered: “deep hemisphere,” “flat hemisphere,” and “flat plate.” The time-dependent strong conservative law forms of the governing equations are written in axisymmetric nonorthogonal curvilinear coordinates. A fully staggered grid system is used for all variables, so that no explicit description of the pressure boundary conditions is necessary. An algebraic grid generation technique is used to map the complex fluid domain onto a rectangle for every time step. Hence the metric of the coordinate transformation can be determined by direct analytic differentiation. The discretized conservation equations are derived from a control volume approach and are solved by using a modification of the simple calculation procedure. The effects of the shapes of cylinder head on the velocity distribution are investigated