Innovative Thermal Management Technologies for Dissipating Full Authority Digital Engine Control (FADEC) Electronics Heat

Overheating of FADEC electronics has become a limiting factor in their capabilities. Current cooling schemes depend on rejecting the waste heat to a flow of fuel, but fuel is not an infinite heat sink. During ground idle operation on a hot day, or late in a flight when most of the fuel has been consumed, fuel temperature can climb to the point where it offers insufficient capacity for continued FADEC cooling. This SBIR proposal offers an alternative scheme, wherein a loop heat pipe in conjunction with thermal electric cooling devices are used to provide cooling to the FADEC package. Loop heat pipes have the capability of moving hundreds of watts of heat distances of 2 meters or longer, with a thermal resistance of 0.03 C/W or less. Thus a loop heat pipe could be configured to transport heat from the FADEC unit to an air cooled heat sink, either at the engine inlet or on the airframe. When combined with TEC’s, significant subcooling can be provided so that potentially the FADEC heat sink interface could operate at subambient temperatures. With this design, FADEC cooling can be disassociated from fuel circulation, to give greater cooling potential and remove critical operational limitations. BENEFIT: Improved cooling of the FADEC module via a loop heat pipe will lead to higher reliability of the FADEC as well as higher reliability of the cooling system. Additionally eliminating dependence on fuel cooling will result in greater operational flexibility. Currently LHP’s are built in low volumes at high costs, primarily for satellite applications. Employing loop heat pipes for FADEC cooling would result in high volume production of LHP''s, with subsequent reduction of unit costs.