Optimization of a Lightweight Gyroid-Based Heat Exchanger for Space Applications

In the framework of human space flights, the active control of temperature inside crewed modules assumes paramount importance in protecting the habitable environment from the harsh thermal conditions of outer space. The need to actively remove the heat from the module is met through suitably sized heat exchangers, as part of the Active Thermal Control Subsystem (ATCS). This requirement must be integrated with the need for lightweight and compact components. A Compact Heat Exchanger (CHX) for space applications, based on Triply Periodic Minimal Surfaces, namely the gyroid, has been designed and manufactured in metal through additive manufacturing. This paper presents two prototypes of a modular heat exchanger, each composed of nine sequential modules arranged in a counter-flow configuration. The first prototype targets the validation of the modular approach and is manufactured and tested to verify the thermal performance and the heat exchanger conceptual design. The second prototype demonstrates the optimized design and manufacturing of the manifolds and connections among the modules. The thermal performance is assessed experimentally using the efficiency-NTU methodology. Overall, it is demonstrated that the performance of the heat exchanger is consistent with that of an ideal counter-flow one, and that the adopted modular approach allows reaching the expected performance.