Compressor Tip Pulsating Pressure Field Testing Technology And Measuring System

In recent years,domestic and foreign aviation compressors often have phenomenons such as block passage blockage,unsteady aerodynamic deterioration,noise aggravation and rotor blade non-co-frequency vibration and leading to blade fracture.It is generally considered to be closely related to the tip clearance flow,which has become a research at home and abroad.hot spot.Due to the limitations of the test methods,the actual compressors are not able to effectively capture the distribution characteristics of the tip eddy currents,which makes the research encounter bottlenecks.Aiming at this problem,a test method of the pulsation pressure field of the compressor tip is studied to effectively measure the distribution characteristics of the tip vortex.In this paper,a wide-frequency response and high spatial resolution sensing array based on piezoelectric thin film materials is designed.A sensor-specific calibration system is developed to solve the accurate measurement of the pressure field.Finally,a complete compressor top pressure fluctuation field is built.The measurement system measures and analyzes the test data to provide support for the compressor design.The main research work is as follows:The piezoelectric properties,main parameters and structures of PVDF piezoelectric thin film materials were studied.Aiming at the testing requirements of the pulsating pressure field of the compressor blade tip,the sensor array with wide frequency response,high sensitivity and strong anti-interference is developed.Firstly,the multi-physics finite element model of the electromechanical coupling of the sensor is established.The variation of the piezoelectric potential of the sensor with the mechanical parameters and structural dimensions of the material and its frequency response characteristics are obtained.The piezoelectric thin film sensor array is designed accordingly.Developed and designed a special calibration system for piezoelectric film sensor arrays to solve the problem of accurate measurement of pressure field.The PVDF piezoelectric film sensor was experimentally calibrated to obtain sensor sensitivity values as well as nonlinearity error,hysteresis error,repeatability error,frequency response characteristics and sensitivity with temperature.A complete compressor pressure field measurement system for the top of the compressor is established for the test environment of the pulsating pressure field of the compressor blade.The measurement study analyzes the characteristics of the tip pulsating pressure field of the compressor under normal and non-steady Conditions,and verifies the effectiveness and superiority of the system by comparison with the Kulite sensor.