Six-Tube Freezable Radiator Testing and Model Correlation

Abstract

Freezable radiators offer an attractive solution to the issue of thermal control system scalability. As thermal environments change, a freezable radiator will effectively scale the total heat rejection it is capable of as a function of the thermal environment and flow rate through the radiator. Scalable thermal control systems are a critical technology for spacecraft that will endure missions with widely varying thermal requirements. These changing requirements are a result of the spacecraft's surroundings and because of different thermal loads rejected during different mission phases.However, freezing and thawing (recovering) a freezable radiator is a process that has historically proven very difficult to predict through modeling, resulting in highly inaccurate predictions of recovery time. These predictions are a critical step in gaining the capability to quickly design and produce optimized freezable radiators for a range of mission requirements. This paper builds upon previous efforts made to correlate a Thermal Desktop™ model with empirical testing data from two test articles, with additional model modifications and empirical data from a sub-component radiator for a full scale design. Two working fluids were tested, namely MultiTherm WB-58 and a 50-50 mixture of DI water and Amsoil ANT.https://ntrs.nasa.gov/search

Design, experimental demonstration, and validation of a composite morphing space radiator

“…26 Other concepts, including stagnating radiators, electrochromic radiators, and freezable radiators have also been tested with mixed success. [27][28][29][30][31] Figure 2 depicts the aforementioned radiator concepts plotted with respect to experimental turndown ratio versus approximate system technology readiness level (TRL) of each design. 1 Only deployable radiators progressed to TRL greater than four (which describes component validation in a laboratory environment).…”