Rectified Continuous Flow Loop for the Thermal Management of Large Structures

Distributed loads are frequently encountered in large deployable structures used in space applications such as optical mirrors, actively cooled sunshades, and on focal plane electronics. One mechanism for providing distributed cooling is via an oscillatory cryocooler such as a pulse-tube that is integrated with a fluid rectification system consisting of check-valves and buffer volumes in order to extract a small amount of continuous flow. This continuous flow allows relatively large loads to be accepted over a long distance with a small temperature difference and has advantages relative to vibration and electrical isolation. Also, it is possible to provide rapid and precise temperature control via modulation of the flow rate. The same working fluid, helium, can be used throughout the entire system, reducing complexity and simplifying the contamination control process.This paper describes steady state and transient modeling results and presents experimental data for a single-stage pulse tube with a rectifying interface that is integrated with a distributed load. The predicted and measured steady state and transient behaviors are compared. The experimental data are used to demonstrate the thermal management concept and illustrate how it can be used for rapid and precise temperature control.