Research And Optimization Of High Frequency Dynamic Pressure Signal Testing Method

The high-frequency dynamic pressure generated by explosion in a thermal vessel is a special concern in the study of explosion mechanics.High-pressure and high-temperature fields are established in the vessel immediately after explosion,accompanied by strong vibration of the structure of the thermal vessel.At this time,there is a wide band and wide dynamic range of pressure in the container,in which the low-frequency static pressure can reach megapa level and the high-frequency dynamic pressure is about kilopa level.Obviously,the dynamic range of high-frequency component pressure is much smaller than that of low-frequency static pressure,which reduces the meas urement accuracy of high-frequency dynamic pressure.In addition,in this environment,the sensor will respond to mechanical vibration and high temperature impact,thus introducing noise interference.This puts forward higher requirements for the performance of high frequency dynamic pressure sensor,noise suppression method and signal acquisition accuracy.Aiming at the noise introduced by testing high frequency dynamic pressure in the abominable environment,a kind of armoured protective buffer device of sensor is proposed to suppress the mechanical vibration noise,and the thermal shock of explosion on the sensor output is reduced by the thermal insulation method coated with silicone grease.Aiming at the small dynamic range of high frequency dynamic pressure signal,a high precision analog conditioning circuit is designed to improve the acquisition accuracy of high frequency dynamic pressure signal.Firstly,the characteristics of high-frequency dynamic pressure generated in the container are analyzed in depth,and the main parameters of high-frequency dynamic pressure sensor,such as dynamic characteristics and frequency characteristics,are introduced.The noise generation mechanism in harsh test environment is analyzed and the protective buffer device is designed to suppress noise.Then,based on the characteristics of high-frequency dynamic pressure and the performance of the sensor,a high-precision adjustment is designed.The circuit mainly includes the design of high precision constant current source circuit of ICP high frequency dynamic pressure sensor and the selection and design of high and low pass filters,in order to improve the signal-to-noise ratio and measurement accuracy,a nd to improve the acquisition accuracy of high frequency dynamic pressure to 0.5.Finally,the test is carried out.In the explosion mechanics test of a thermal vessel,the high frequency dynamic pressure sensor is mounted,the test data are collected,processed and analyzed,and the physical process is restored.