Experimental design of response surface methodology was adopted to construct the inlet pressure distortion prediction model based on flight test data

while the inlet distortion model prediction and flight test verification were studied under different flight conditions. The results showed that

compared with the flight test results

the model prediction average relative error of the comprehensive pressure distortion index was 421%

and the average relative error of the steady-state circumferential distortion index was 799%

which were in agreement with each other and can meet the requirement of the inlet distortion prediction. At large angle of attack

sideslip and combined flight conditions

the flow separation of the boundary layer inside the inlet contributed a lot to the distortion of the inlet outlet. The position of the inlet outlet low pressure zone corresponded to the flight attitude angle

and there was a small range of deflection in the direction of the compressor rotation in the circumference direction

and the deflection angle was related to the engine state. The model of “model prediction+flight test” can be used to evaluate the distortion characteristics of aircraft inlet completely

safety and efficiently

and it has good engineering practicability.