All Electric Cooling System for Unmanned Aircrafts

Abstract

This study brings out two All Electric Environmental Control System (AE-ECS) configurations for Unmanned Aircraft air-conditioning and performance evaluation of these two configurations interms of power consumption and fuel mass penalty. In conventional (or traditional) Bleed Air System, hot air is extracted from the engine compressor whereas in Bleed less Air Cycle system/Bleed less Vapour Cycle Systems (also called AE-ECS) bleed air extraction from engine is eliminated. Eliminating the extraction of bleed air from the engine in both the systems of Bleed less Air Cycle and Vapour Cycle System, saves the engine energy and thus increases the engine efficiency/thrust. In the present study performance of the Bleed less Air Cycle and Vapour Cycle systems are studied for typical flight envelop and heat loads of 5 kW. Bleed less Vapour Cycle System consumed less electric power compared to Bleed less Air Cycle System when compared for 5 kW cooling system requirements for an Unmanned Aircraft system. Fuel mass penalties are also calculated and compared for these two system configurations.