Abstract
The temperature-entropy diagram for α-type Stirling Engines is obtained on the basis of the adiabatic model of Finkelstein(1962). With his model the thermodynamic processes in practical engines can be analyzed, and the relationship between the pressure and volume of the working gas may be obtained. Then, using the pressure thus obtained, both the relationship between the mixing-cup temperature and 'mixing-cup entropy', and the diagram of temperature- entropy are obtained based on the method proposed by Oyama (2000). By comparing it with the cycle for the isothermal model, the characteristics of the cycle for the adiabatic model are clarified. It is found that, when the dead volume and temperature ratios are small, the traces of the cycle of the adiabatic model resembles the Arabic figure 8, which means that the cycle has both the characteristics of a heat engine and a refrigerator. The optimum heat storage of regenerators is also obtained which realizes the Carnot efficiency under given temperature conditions.
