Abstract A motion-capturing pressure sensitive paint (PSP) system is developed and demonstrated by collecting transient pressure data on the surface of a 30 mm diameter sphere model in free flight at Mach 1.5, where a conventional pressure tap is unable to be mounted. The developed non-intrusive measurement technique is able to cancel out changes in signal intensity due to variations in illumination during free flight. Images of the sphere model are collected using a high-speed camera at a rate of 100 kHz with an exposure time of 3.75 μs. Motion blur is estimated as 6.5% of the sphere diameter. The sphere is fully in view for 7 frames, or 70 μs. Transient data from each frame is collected to produce a free flight pressure map on the surface. In order to validate the measurement, a time-averaged CFD simulation of a sphere model at Mach 1.5 is run using far field pressure boundary conditions and a mesh of 6.96 million cells. An uncertainty analysis is performed using the signal to noise ratio of the PSP measurement. The PSP measurement is in agreement with the CFD simulation quantitatively across a centerline pressure trace. The accuracy of the PSP measurement compared to the CFD simulation was within 7.4 kPa.

中文翻译：

---

使用新型非侵入式光学技术在 1.5 马赫的自由飞行模型上进行亚毫米分辨率压力测量

摘要 通过在 1.5 马赫的自由飞行中收集直径 30 mm 球体模型表面的瞬态压力数据，开发并演示了一种运动捕捉压敏涂料 (PSP) 系统，在该系统无法安装常规测压器。开发的非侵入式测量技术能够抵消由于自由飞行期间光照变化而导致的信号强度变化。使用高速相机以 100 kHz 的速率和 3.75 μs 的曝光时间收集球体模型的图像。运动模糊估计为球体直径的 6.5%。球体在 7 帧或 70 μs 内完全可见。收集每一帧的瞬态数据以在表面上生成自由飞行压力图。为了验证测量结果，我们对 1 马赫的球体模型进行了时间平均 CFD 模拟。图 5 使用远场压力边界条件和 696 万个单元的网格运行。使用 PSP 测量的信噪比进行不确定性分析。PSP 测量与 CFD 模拟在中心线压力轨迹上定量一致。与 CFD 模拟相比，PSP 测量的精度在 7.4 kPa 以内。