正弦波型高频动态压力光学校准系统及其应用

A high frequency dynamic pressure optical calibration system based on sinusoidal wave and its application

动态压力是气动部件表面的关键气动参数。光学压力敏感涂料(PSP)测量技术在测量气动部件表面动态压力方面具有全域测量、不影响流场自身的优势,而光学压力敏感涂料的动态响应特性则是进行动态压力测量的决定性因素。基于声学驻波管原理,自主设计并组建了正弦波型高频动态压力光学校准系统,主要包含有驻波管型校准舱、声源、激光源、高频压力传感器、光电倍增管以及测控系统。对动态压力光学校准系统及某新型快响压敏涂料的实验结果表明,所组建的动态压力校准系统可产生最短响应时间12.5μs、最大压力幅值为4.37kPa的正弦型动态压力,其有效动态频响范围为0.4~20.0kHz(50μs^2.5ms),不确定度小于0.0049%;校准系统合理的光路布局可进行快响压敏涂料动态特性的校准,所测涂料可用于动态频响不高于9.1kHz(响应时间为109.9μs)的非定常流场的压力测量。

Dynamic pressure is a key aerodynamic parameter on pneumatic model surfaces.An optical technique using Pressure-Sensitive Paint(PSP)provides an advantage in obtaining full-field and low aerodynamic interference images during measurement of dynamic pressure on pneumatic model surfaces,while the dynamic response characteristic of the optical pressure sensitive paint is critical to dynamic pressure measurement.Based on the principle of acoustic standing wave tubes,a high frequency dynamic pressure optical calibration system with sinusoidal waves is designed and established independently,including a calibration chamber based on the standing wave tube,a sound source,a laser,a high frequency dynamic pressure transducer,aphoto multiplier tube,and a system for measurement and control.The test results of the dynamic pressure optical calibration system and a new kind of fast pressure sensitive paint indicate that the shortest response time of the dynamic pressure calibration system,set up independently,is 12.5μs,while the largest sinusoidal dynamic pressure amplitude can reach up to 4.37 kPa,with the valid dynamic frequency varying from 0.4 to 20.0 kHz(50μs^2.5 ms),and the uncertainty less than 0.0049%;reasonable light layout of the calibration system guarantees the calibration of dynamic characteristics for fast pressure sensitive paint,and the paint measured can be utilized in pressure measurement of unsteady flow fields with a dynamic frequency below 9.1 kHz(response time of 109.9μs).