Numerical predictions of flow and thermal fields in a reciprocating piston-cylinder assembly

An efficient solution method for predicting unsteady, compressible flow and thermal fields in a reciprocating piston-cylinder assembly is developed in this study. The solution method, based on a two-stage pressure correction scheme, is applies for simultaneously determining the absolute pressure, de nsity, temperature, and velocity components of the fluid inside the cylinde r at any instant during the start-up and periodically stable periods. Discr etization equations are derived from the integral mass, momentum, and energ y equations on a moving grid, which is deforming to accommodate the movemen t of the piston. A test problem of solves by means of the proposed method t o illustrate the validity of the numerical procedure procedure. Results sho w that the two-stage pressure correction scheme can be readily incorporated into existing numerical techniques to yield reasonably accurate results. E ffects of the factors, including gravity (g) and rotation speed of the cran k shaft (f), thus can be evaluated.