Speakers
Description
Pulsating Heat Pipes (PHPs) are promising passive thermal control devices for space applications due to their high heat transport capability, design flexibility, and relatively simple wickless construction. However, the oscillatory motion of the working fluid may generate microvibrations that could affect sensitive spacecraft systems.
This work presents the thermal and microvibration characterization of two PHP breadboards developed within the MITIGATE project carried out for the European Space Agency (ESA). A large breadboard was developed for phased array antenna cooling with a target transported power of 200 W, and a small breadboard for detector plane cooling with a target of 30 W. Under nominal operating conditions, the large breadboard achieved a thermal resistance of 0.019 K/W at 200 W and 65 °C, while the small breadboard achieved 0.192 K/W at 30 W and 45 °C. Thermal performance and operational stability were strongly influenced by condenser temperature, orientation, and heat load, particularly near the operational limits. The presentation will discuss these effects and highlight the key operational trends observed during the test campaign.
Microvibration measurements demonstrated benign dynamic behavior, with RMS force levels well below the 0.2 N requirement. Occasional impulsive force events exceeding the specified peak-force limit were observed; however, additional tests without working fluid demonstrated that these events originated from the ground support equipment rather than from the internal two-phase flow. Overall, the results confirm the feasibility of PHP technology for space thermal control applications requiring efficient heat transport with low exported microvibrations.