The effect of dimension limits on the performance indices of Stirling engine MAC-02

The paper presents a comparative study of different Stirling engine MAC-02 specifications. The MAC-02 is the engine of beta configuration with heater and cooler tubes drilled inside the cylinder wall and connected by an annular regenerator of wire mesh type, surrounding the cylinder. Piston and displacer are driven by Ericsson linkage, which brings some advantages with respect to other conventional drives, however, for its complexity it has not been considered yet in published Stirling engine optimization codes. The most difficult aspects in designing such an engine configuration is the strong interdependence among constructional parameters particularly drive rod angularity, rod, cylinder, piston and heat exchanger dimensions. For this reason a special method for the optimal engine synthesis was elaborated and presented in Impero Abenavoli, R., et al. (1993). The corresponding computer code SE-OPT was used to obtain results discussed in this paper. A number of the engine design specifications were calculated and compared one to another. Each of the cases under consideration was determined as the optimal solution of non-linear programming problem defined with different engine dimension boundaries. The maximum of indicated power was chosen as the objective function. Although several tens of constraints were included into the optimization problems, onlymore » the limits imposed on the total engine length and cylinder diameter are analyzed in this paper. The two parameters were considered as variables dependent on the other ones (free and fixed parameters). The effect of these main engine dimension limits on selected performance indices (indicated power and efficiency) and the optimal values of other ensure parameters such as heat exchanger dimensions, linkage parameters and piston phrase angles were investigated.« less