进气道内窥式高频PIV测量技术研究

Study on High Frequency Endoscopic PIV Measurement Technique in Inlet

为了掌握复杂S弯进气道内流分离等非定常流动特征,直观定量地获取进气道内部瞬时速度场信息,本文发展了一种适用大型风洞不透明进气道模型的内窥式高频粒子图像测速(PIV)测量技术,开展了内窥式光路布局设计、内窥部件气动干扰、环境背景光干扰等问题研究,在低速风洞中,风速10~64m/s,PIV测量频率1kHz条件下,开展进气道内特定部位的非定常流场测量,获取了进气道内速度场随来流风速和流量系数的变化规律,捕捉到了特定来流风速与小流量工况下瞬时速度脉动分量的周期性振荡现象。试验结果表明,该项技术可为风洞试验中复杂进气道内流问题诊断提供一种有效的解决方法。

This paper presents a technique to measure the transient velocity field inside the inlet intuitively and quantitatively in order to study the unsteady flow characteristics such as flow separation of the complex S-shaped inlet.The key research points include endoscopic optical path layout,endoscopic components aerodynamic interference and background light interference,a high frequency endoscopic PIV measurement technique suitable for opaque inlet model in a large wind tunnel is developed.The technical verification for a specific section of the inlet is carried out under the conditions of wind speed of 10~64m/s and measurement frequency of PIV under 1kHz,the correlation of the internal velocity field with wind speed and flow coefficient is obtained,and the periodic oscillation phenomenon of transient fluctuating velocity components under certain wind speed and low mass flow is captured.The test results show that the technique can provide an effective solution to the diagnosis of complex inlet internal flow problems in wind tunnel tests.