Phase Shift Effect of the Long Neck Tube for the Pulse Tube Refrigerator

This paper discusses the effect of a long neck tube inserted between the reservoir and the pulse tube hot end. To improve pulse tube performance, the pulse tube enthalpy flow divided by the regenerator mass flow needs to be maximized. From the view point of the equivalent PV diagram at the cold end of the pulse tube, the optimum performance will be given by the PV shape of the idealized Stirling cycle. However, in the case of the orifice pulse tube, the phase shift effect generated by the orifice and reservoir is not sufficient. The double inlet pulse tube can approach the PV shape of the idealized Stirling cycle, but this configuration requires additional work input. The computer simulation developed in this study indicates that a long neck tube with a reservoir, instead of the orifice and the double inlet, gives an improved PV diagram with no additional work.