Numerical simulation of performance of a double-acting alpha-type stirling engine

Abstract

Computational Fluid Dynamics (CFD) analysis is one of the most important powerful processes in commercial engine project, which is going to give the engineers the overall vision that a simulator may want to know about. It could save lots of time and costs before people actually manufacture the engine. This paper deals with numerical simulation of a double acting alpha-type Stirling engine (DASE), which has four cylinders with four pistons moving respectively. In the engine, double actions of the four pistons take place in two opposite chambers in each of four cylinders. For each cycle, the piston alternately moves backand- forth in a cylinder by the connecting expansion chamber of a cylinder to the compression chamber of the next cylinder with a channel, the pressure difference between the expansion and compression chambers is increased and the power capacity of the engine is improved. In this paper, the numerical module is built based on the frame of commercial CFD software (FLUENT). The user-defined functions (UDFs) of the software are adapted so that the movement of those pistons in those cylinders can be simulated. Periodic changes in temperature, pressure and velocity fields in the engine are predicted and the power output of engine is obtained.