High-altitude air inlet pressure distortion test method for small-bypass-ratio aero-engine

The invention provides a small-bypass-ratio aero-engine high-altitude air inlet pressure distortion test method which comprises the steps: a numerical simulation technology is applied, the pneumatic flow field condition in a flow pipe during an engine maximum state test is simulated, the position of an inserting plate is determined, and the position of the inserting plate guarantees that air flowis not affected by interference of an air inlet flow guide basin and the inserting plate; a second vortex position of a turbulent flow pressure field generated by the plugboard at a critical depth isjust positioned on a pneumatic measurement cross section of an engine inlet; at least six dynamic total pressure sensing parts are arranged, and dynamic pressure signals in a flow pipe flow channel are obtained through the dynamic total pressure sensing parts; data processing is carried out on the dynamic pressure signal to obtain a steady-state circumferential total pressure distortion index anda ring surface average turb