Simulation research of low fuel penalty half-closed loop air cycle cooling system

Abstract

In order to reduce the fuel penalty and engine bleed air capacity, under the premise of satisfying cooling and pressure stability demands for airtight cabin, a new half-closed loop air cycle system (ACS) driven by a power turbine was presented. To verify the cooling capacity of this new system, a simulation investigation based on LMS AMESim software was carried out. The simulation modules of turbine cooler, ejector, water separator and heat ex-changers have been established. To avoid the ice barrier at condenser outlet, the heat transfer efficiencies of regenerator and condenser were set at 0.25~0.30. Using the same cooling capacity of F-22 fighter's ACS package as the design parameter, the engine bleed air was found to decrease up to 45% for this new half-closed loop ACS when compared to the open-type ACS in theory.