Designing a stirling engine prototype

Abstract

Stirling engines have become of great interest on the last decades due to their efficiency and sustainable energy production. This study develops one of the first phases of the design of a Stirling beta type engine - able to generate 1kW of power-including the specification of basic components of the engine and a thermodynamic simulation (by Computer Fluid Dynamic-CFD) with real parameters. The approach comprises thermodynamic improvements of the engine, which are the base for an improved design. The methodology consists of various consecutive steps such as design procedures, theoretical calculations, simulation process description and analysis of results obtained. The first phase defines the model geometry, specifying the volume occupied by the working gas, equations that define the power and shifter pistons movements and dimensions of all components that perform the engine. After defining the inner volume, the mass of gas inside the engine is calculated, and hypothetical contour conditions are established. Based on these data and following the theoretical ideal engine process, it is possible to obtain the theoretical P-V diagram, as well as the engine power and efficiency through a basic thermodynamic analysis. This procedure is repeated as many times as needed in order to get the desired results. By modifying different parameters, it is possible to find a suitable design that combines geometry and contour conditions, and therefore approach to the design power.