Impact Of Swept Volume Ratio In Designing A Beta Type Stirling Engine

Abstract

A Stirling engine is an external combustion engine operating on a closed regenerative cycle. The working relies on cyclic expansion and compression. The displacer which is meant for shuttling the hot gases from the displacer space may share a part of volume with the piston known as overlap volume. In this paper, an appropriate model for beta type Stirling engine is developed for optimizing its efficiency based on the swept volume ratio (SVR), i.e., the ratio of swept volume of piston space to that of the displacer space. The analysis of impact of SVR on other parameters like phase angle and overlap volume has also been the part of this research. Based on the achieved results, it is observed that an optimum combination of swept volume of displacer and the piston space ensures the efficient working of the beta type Stirling engine and its efficiency increases with the increase of SVR but its impact lessens gradually as the SVR value increases by unity. The influence of phase angle and overlap volume on swept volume ratio is also investigated. The results are represented graphically. From this study, it is concluded that the required efficiency of the beta Stirling engine can be achieved by suitable combination of the discussed parameters