Assessment of the necessity of cooling of the Stirling engine expansion piston

Abstract

Heat balance of the Stirling engine expansion piston is investigated. This balance considers heat flows that are applied to the expansion piston from outside parts, generated by friction in the piston-liner contact zone, and rejected to the cooling medium. The average heat transfer coefficient is obtained by means of division of a predicted value of the thermal conductance by cooled area of the expansion piston. Dimensionless variables are derived from an expression for determination of the thermal conductance, and the dimensionless chart is presented.