Design and analysis of a novel thermal management system for serving next-generation aircraft with megawatt-level heat loads

Abstract

Due to the development of electronics and high-energy pulse devices, in conjunction with the increasing flight speeds, the instantaneous heat load of next-generation aircraft will reach the megawatt level, which poses severe challenges for thermal management. To improve the heat dissipation capability, this paper presents a novel thermal management system (TMS) employing liquefied natural gas (LNG). This TMS design incorporates four merits: LNG and fuel share the heat load of electronics which dramatically enhances the mission time; the air circulation subsystem selects different combinations of heat sinks depending on the engine's operational state; LNG spray cooling efficiently handles the heat load of directed energy weapons; the heat sinks release the cooling capacity in a temperature gradient to maximize efficiency. The performance of the TMS is verified in a harsh flight profile. The selection of an appropriate return location and the storage of low-temperature fuel can enhance the efficiency of the fuel heat sink. An effective means of improving the vapor compression subsystem's efficiency is increasing the withstand temperature of the electronics. The introduction of LNG extends mission time by more than three times with minor fuel penalties. The potential for utilizing turbines to enhance LNG cooling efficiency is explored.