Analytical Investigation of Thermal Management Options for an Aircraft Based High Pulsed Power System Application

Abstract

A general thermodynamic analytical investigation has been conducted to assess the impact of thermal management related conceptual improvements on the overall performance of thermal management system (TMS). The power system, for which the TMS is being analyzed, essentially consists of a prime power source, electrical power generator, power conditioner, pulsed power source and pulsed power processor. The TMS analysis corresponds to a notional aircraft mission, with the turbo-shaft engine operating at a fixed altitude. It has been assumed that heat from various system components is collected by the same coolant loop, and then rejected to ambient air in a ram air heat exchanger (RAHX). The acquisition of heat from the pulsed power tube, the major contributor to the heat load, has been assumed to be done by single-phase, sub-cooled boiling process and from the remaining components by forced convection. In this analysis, only the management of aggregate heat load is treated, ignoring individual component-level details. Standard air properties at the mission altitude and designated air speed have been used in the design of the RAHX. Three closed-loop cooling schemes and two RAHX configurations have been considered. Results show that for both of the RAHX configurations, raising the hot fluid operating temperature results in considerable system mass saving. It has also been found that operating the RAHX continuously, with a “balanced” heat load, leads to considerable savings in RAHX, and hence TMS, mass.