Through an analysis of the start-up principle of two-wheel bootstrap air cycle machine (ACM) with foil air bearing

the method to calculate the start-up pressure has been established has been established.According to this method

a program has been composed to calculate the start-up pressure of one ACM under different conditions.The calculation results matched the actual test data well

which demonstrates that this calculation method is of high accuracy.Calculation and analysis show that the turbine outlet pressure and the bearing preload have great effects on the bearing start-up pressure.The lower the turbine outlet pressure

the lower the start-up pressure is.Meanwhile

the greater the preload

the higher the start-up pressure is.