Investigation of the effect of compression ratio on performance of a beta type Stirling engine with rhombic mechanism by CFD analysis

Abstract

Stirling engines take attention due to their high thermal efficiency potential. Many experimental and numerical studies have been performed up to date. Numerical performance analyses of Stirling engines implemented with CFD simulations are classified as 4th order analyses. In the present study, the effect of compression ratio on engine performance of a beta type Stirling engine with rhombic mechanism was investigated by 2D CFD simulation. CFD simulations of the Stirling engine were performed by ANSYS Fluent software. The engine examined by CFD analysis was modeled using the dimensions of an engine manufactured and tested in a previous study, and validation of the CFD simulation was conducted regarding in-cylinder pressure at 4 bar charge pressure. The crank radius and length of the regenerator zone of the engine were optimized by considering the compression ratio of the engine and engine performance was investigated. Maximum engine performance was obtained at a compression ratio of 2.24 which was ensured by 31.5 mm crank radius and 609.9 mm a length of the regenerator zone. By optimizing the dimensions the engine performance was improved by 99% compared to the base engine configuration. The cyclic work, power, torque, and thermal efficiency were calculated as 62.47 J, 728.93 W, 9.94 Nm, and 37.7% respectively.

A Comprehensive Review on Stirling Engines

“…In low pressure Beta-type Stirling engines, the regenerator area is positioned around the displacer piston, and the flow the working fluid between the hot-cold volumes is ensured through the space between this piston and the cylinder. In this type of engines, it is necessary to increase the length of the displacer piston, and in engines operating with high charge pressure, the heat transfer surface area should be increased [50]. Increasing the heat transfer surface area is possible by using a separate heater, cooler and regenerator.…”

CFD Analysis of Sloshing in the Fuel Tank of a Heavy Vehicle with Emergency Braking System

“…With the CFD method, all properties and parameters such as acceleration, force, flow regime, liquid properties, tank geometry, filling level, antislosh baffle geometry, number, and location can be tested in different combinations to determine the optimum design. Unlike experimental studies, these analyses are reproducible, cost-effective, and time-saving [21][22][23]. Various numerical methods are used for the sloshing analysis of fuel tanks by the CFD method.…”