Expansion efficiency of pulse tube in pulse tube refrigerator including shuttle heat transfer effect

This paper describes simple analysis of the pulse tube expansion efficiency. Four dimensionless operating parameters of pulse tube refrigerator are needed to express the enthalpy flow at the cold end of the pulse tube. In this analysis, the expansion efficiency is calculated from the ratio of the diathermic enthalpy flow (non-zero gas-to-wall heat transfer) to the adiabatic enthalpy flow (zero gas-to-wall heat transfer). The analytic procedure is carried out under several simplified assumptions, and the resultant expression is remarkably simple and useful. The optimal design of pulse tube refrigerator can be greatly assisted by the enthalpy flow calculation with four dimensionless parameters introduced in this paper.