Study On Acoustic Temperature Measurement Technology For Temperature Field Of Solid Rocket Motor Exhaust Flame

With the rapid development of China’s aviation industry,the indicators and performance of solid rocket motors have higher requirements than before.The tail flame temperature of solid rocket motor is an important reference index to measure the working performance of rocket engine,and the accurate measurement of tail flame temperature distribution characteristics is the reference basis for rocket engine improvement.Therefore,the test of the tail flame temperature field is crucial for rocket engines.Due to the high temperature and rapid change of the tail flame temperature field of rocket engines,the traditional single-point temperature measurement method cannot meet the actual needs.Therefore,based on the theory of ultrasonic temperature measurement,this paper explores and solves the problem of temperature field reconstruction in complex environments for the field of solid rocket motor.According to the current temperature measurement status of the tail flame of solid rocket motor,an ultrasonic temperature measurement technology with high sensitivity,fast response speed,strong anti-interference ability and wide temperature measurement range is proposed for detection.In this paper,the ultrasonic temperature measurement model is derived based on the principle and method of ultrasonic temperature measurement,and the overall design scheme of ultrasonic temperature measurement is determined.Through the temperature measurement model and the key parameters of the transducer,the temperature measurement experiment and the optimal design of the transducer are theoretically guided and confirmed by each other.Multiphysics finite element simulation calculations were used to compare the shape,number and distance of key parameters of transducers,and array sensors were developed.During the construction of the overall experimental system,the transmission and receiving circuits of the excitation signal are developed to complete the signal transmission and reception,and then the data is collected and transmitted to the host computer for post-processing.The host computer realizes multi-channel data acquisition and data storage,and realizes system parameter setting,waveform display and other functions.Build a system platform,carry out single-channel sensor and array sensor test tests,and accurately calibrate with thermocouples.The cross-crossing time is accurately calculated by cross-correlation algorithm,and the relationship between jet lag and temperature change is determined.By polynomial function fitting,the time difference-temperature characteristic curve is obtained.Comparative analysis,the test shows that the temperature field in the range of 25 °C ～ 1000 °C,the average relative error is 5.10% and 4.06%,the maximum relative error is 5.03% and 4.89%,and the root mean square error is 4.64% and 4.19%,respectively.This test can better display the temperature field distribution information,prove that acoustic temperature measurement has a certain effectiveness in the application of solid rocket motor,and lay the foundation and provide reference for the temperature test of solid rocket motor tail flame.