Fault Analysis Of The Air Cooling System Based On Numerical Simulation Of Fault Turbine

The failure of environmental control system is becoming more and more frequent.The failure simulation analysis of the system can enable us to get the failure relevant parameters effectively,safely and economically.This paper shows a possible method to conduct systematic failure analysis,specifically we conducted failure modeling and flow field analysis,then based on the characteristic of turbine malfunction we will plug in this failure into the system to capture the effect of malfunction on the system.The main contribution is: Designing and modeling the turbine;through the investigations associated with turbine failure,we conducted malfunction modeling and CFD statistic simulations.The calculation results show that when keeping air's temperature and mass flow in the turbine entrance constant,the malfunction turbine's temperature and the refrigerating capacity is reduced,the turbine's efficiency decreased;through statistically fitting the characteristic curve of the turbine failure,it is clear to see that with the increase of expansion ratio,the reduced flow rate of the malfunction turbine is higher than a normal turbine.By building environmental control system of aircraft under Matlab/Simulink;we assembled the malfunction turbine modeled by the turbine's characteristic curve,it is then placed in the environmental control system instead of the normal turbine to simulate the operation.We compared and analyzed the influence of turbine failure on the system.The simulation results show that turbine failure causes turbine cooling capacity to decrease,so that the maximum cooling capacity of the system is reduced.