Passive thermal Management for High-Temperature Aircraft Actuation Systems

The proposed program will develop an integrated passive thermal management (TM) system to support the "power-by-wire" technology originated with the Air Force Research Laboratory. The TM system can operate in a wide range of environmental temperature (from -55 to 200 C) and under a variable gravity situation (up to 9g). A cold plate impregnated with a phase change material (PCM) in channels will absorb heat during periods of peak power and high-g. A porous heat pipe (PHP) will be developed to spread heat from a heat flux of 3 W/cm^2 at the cold plate to less than 1 W/cm^2 at the aircraft skin. Microcapsulated PCM particles can function as a wick as well as provide additional thermal energy storage capability. The feasibility and effectiveness of the proposed concept will be demonstrated by measuring the apparent thermal conductivity and heat flux limit of the porous heat pipe over a wide range of temperature. A complete thermal management system for an electronic unit of the aircraft actuation system will then be designed in the Phase I effort.