Application of an optical pressure measurement technique with pressure-sensitive paint to blow-down supersonic wind tunnel testing

压敏涂料光学压力测量技术在吹扫超声速风洞试验中的应用

基本信息

批准号：
12650176
负责人：
SUZUKI Tateyuki
金额：
$ 0.64万
依托单位：
Toyama Prefectural University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Pressure-sensitive paint (PSP) attracts attention as a novel optical pressure measurement technique to obtain the full-field pressure distribution with very high spatial resolutions. However, conventional polymer-based PSPs cannot be used in short-duration supersonic wind tunnels of blow-down type due to the slow response to a rapid change in pressure. The aim of the present study is to establish PSP measurement technique applicable to aerodynamic tests in blow-down supersonic wind tunnels by improving the time response of PSP itself and the stability of excitation lights. The main results of the present work are as follows:1. The fluctuation of the output of a blue light-emitting diode (LED) array light source is extremely small (less than 0.2%), hence it is suitable for the illumination light for the PSP measurements in short-duration wind tunnels of blow-down type.2. The time constants of PSPs based on porous thin-layer chromatography plates are on the order of 10 microseconds. The fast-responding porous PSP has been applied to a surface pressure measurement in a Laval nozzle of the blow-down wind tunnel of Toyama Prefectural University, and pressure jumps due to a system of oblique shock waves generated in the nozzle wall and temporal fluctuations of the shock locations have been successfully visualized.3. The wall temperature change during a run seriously affects the pressure measurements. The use of a thermally-conductive adhesive tape to fix the porous PSP on a brass wall (as a heat sink) was effective to reduce the surface temperature change during the experiment.4. The signal-to-noise ratio (SNR) of a single image obtained is not enough due to the inevitable shot noise. It suggests that the image processing procedure for the noise reduction is important for PSP measurements in short-duration wind tunnels.

压敏涂料（PSP）作为一种新颖的光学压力测量技术引起了人们的关注，它可以获得具有非常高空间分辨率的全场压力分布。然而，传统的聚合物基PSP由于对压力快速变化的响应缓慢而不能用于短时吹扫型超音速风洞。本研究的目的是通过提高PSP本身的时间响应和激发光的稳定性，建立适用于吹气超音速风洞气动测试的PSP测量技术。本工作的主要成果如下： 1．蓝色发光二极管（LED）阵列光源的输出波动极小（小于0.2%），适合作为短时排污风洞中PSP测量的照明光类型.2。基于多孔薄层色谱板的 PSP 的时间常数约为 10 微秒。快速响应的多孔PSP已应用于富山县立大学吹气风洞拉瓦尔喷嘴的表面压力测量，由于喷嘴壁中产生的倾斜冲击波系统和压力的时间波动而导致压力跳跃。冲击位置已成功可视化。3．运行期间壁温的变化严重影响压力测量。使用导热胶带将多孔PSP固定在黄铜壁上（作为散热器），可以有效减少实验过程中表面温度的变化。 4．由于不可避免的散粒噪声，所获得的单张图像的信噪比（SNR）是不够的。这表明降噪的图像处理过程对于短时风洞中的 PSP 测量非常重要。