This heat transfer system removes heat in zero gravity through conductance using vibrations induced by an AC electrostatic force. Heat transfer in microgravity is limited in the absence of buoyancy-driven convection. The conventional heat transfer approaches on Earth utilize buoyancy-driven flow and do not work in space, particularly in closed-loop systems requiring external pumps. As high-powered electronics become smaller and more powerful, heat must dissipate. Current thermal management breaks into active or passive thermal control systems.
Active thermal control systems require power input to operate, while passive thermal control systems do not. In active systems, pumped fluid systems decrease sensitivity to pressure drops, increase flow rate control, and achieve more precise temperature control within allowable margins. However, prominent disadvantages of active systems are the associated mechanical pump, requiring an electrical input that consumes part of the spacecraft’s power budget, and the potential cavitation of pumped systems, introducing possible system failures. On the other hand, passive systems do not use mechanical pumps, lowering the risks of system failures, but have a minimum startup heat flux. Electrostatic resonance can enhance heat transfer in microgravity.
Researchers at the University of Florida have developed a heat transfer control system able to function in zero-gravity environments. It removes heat through conductance using vibrations induced by an AC electrostatic force, showcasing a substantial increase in heat flux. The dissipated heat is applicable for heating and converting to mechanical energy.
Active heat transfer system uses AC electrostatic resonance to remove heat in microgravity
This heat transfer management system composes two water baths, at the top and bottom of the device, held at a constant temperature. Between the water baths sits an aluminum electrode at the top boundary and an indium tin oxide (ITO) coated glass electrode at the bottom boundary. Both these electrodes are sapphire, an electric insulator, directing the electricity to flow through the fluids as intended. A voltage and frequency are applied across the electrodes, causing electrostatic fields to create wavelike patterns for increasing the heat flux. This device combines the reliability of active thermal management and the ability of passive thermal management to avoid cavitation and mechanical failure.