Some Applications of Liquefied Gases in Cooling Systems in Aircraft and Missiles

Abstract

For economic or military reasons, aircraft operate at high altitudes, and it is essential to provide an artificial environment for the crew, passengers (if any), and for certain classes of equipment. Air for cabin pressurization and conditioning is obtained from blowers or the engine compressor and generally needs to be cooled. In many aircraft presently in service, ram air taken from the boundary layer is used as the cooling medium. However, at low levels the ram air is frequently too warm and further cooling is required. An open-cycle refrigeration system with air as the working medium is used for this purpose.