Supplemental Cooling Using Phase Change Material for High Temperature Transient Capability

A unique modular heat exchanger (HEX) incorporating Phase Change Material (PCM) is proposed for storing high transient thermal loads in the F-35 aircraft. The modular HEX employs a foam metal lattice within the PCM to enhance conduction. In addition, a foam metal lattice is included within the fuel coolant passages to enhance heat transfer by increasing surface area and by generating increased turbulence in the fuel. The PCM provides thermal storage for high transient thermal loads, allowing the baseline cooling system to be sized for steady-state loads, while the modular PCM system to be used for removing the high, off-design transient loads. This design approach allows the cooling system to be sized for the lower steady-state loads, minimizing its size and weight. The proposed Phase I analytical effort will demonstrate feasibility of the PCM HEX by analysis, while the Phase I OPTION will fabricate and test a HEX concept to validate the new analytical tools and demonstrate the PCM HEX concept. Test results will be used to refine the Phase I analytical tools and design, which will form the foundation of the Phase II detail design.