Investigation of the effects of compression rate on engine performance in a beta type Stirling engine with rhombic mechanism by numerically

In this study, a full simulation model of a beta type Stirling engine with rhombic motion mechanism was created with Ansys Fluent software. In the creation of this simulation model, in which the test conditions and engine characteristics can be changed, the characteristics and test conditions of the test engine, which was produced and tested with a Tübitak project, were taken as a basis. The compression ratio was changed with the dimensional changes made on the test engine and an optimization study was carried out by examining the effects of these changes on the engine performance. In the studies in which four different analysis setups were applied; for beta type Stirling engine, parameters such as compression ratio, crank radius and length of regenerator zone have been optimized and the changes in engine performance due to these parameters have been determined. As a result of the optimization, maximum engine performance was determined at a crank radius of 31.5 mm, a length of the regenerator zone of 609,9 mm and a compression ratio of 2,24. The cyclic work, power and torque values at this compression ratio were calculated as 62,47 J, 728,93 W, 9,94 Nm, respectively. The thermal efficiency obtained as a result of the optimization is 37,7%. When the validation results and optimization results were compared, it was observed that the engine performance increased by 99%.