Investigations on nonlinear processes of a Gifford-McMahon type orifice pulse tube refrigerator

Abstract

The target of this investigation is to illustrate the nonlinear fluid flow, heat transfer, and vortex formation phenomena in an orifice pulse tube refrigerator by numerical simulation. Numerical results confirm that jet streaming is generated at the low-temperature end of the pulse tube in between the junction of U-shaped tube and pulse tube. The primary vortex, which is generated due to the minor loss, continuously grows because of velocity change and eventually leads to the formation of secondary eddy. Consequently, flow straighteners have been adopted at the hot side of the regenerator, hot heat exchanger, and both sides of U-shaped tube. It is noticed that, jet streaming has been suppressed at the cold end of the pulse tube. Nevertheless, the streaming effect generated due to the oscillating flow of the gas parcels within the pulse tube, and third type of streaming have not been suppressed with the flow-straightener. Additionally, the numerical simulation shows different gas flow behaviors within the pulse tube that occurs due to the oscillating pressure pulse. An experimental investigation is conducted to compare experimental results with the numerical results and a valid agreement is observed between them.