Time Dependent Particle Image Velocimetry (PIV) Measurement via Linear Stochastic Estimation (LSE)

目前，由于脉冲激光带宽的限制(通常为15赫兹或更低)，CTS-9809784粒子图像测速仪无法在足够高的采样率下进行实验测量。这在处理高雷诺数流动时会产生问题，特别是在需要更多流动快照的情况下，尤其是与时间相关和随时间变化的流动。这项研究的目的是开发和微调一种基于二维(2-D)空间线性随机估计(LSE)的技术，该技术将为低采样率问题提供解决方案。该方法结合了热线突出的时间带宽特性和PIV的超高空间分辨率。通过热线风速法测量空间中几个最佳选择的点的瞬时速度，然后在剩余的空间位置估计同步速度，在这些位置上，从PIV测量获得的关联是已知的。这项新的重要技术可以在克拉克森大学得到最大限度的发展。此外，PIV系统将为实验湍流实验室增加急需的能力，并将影响目前和未来的几个主要实验研究项目。

Abstract CTS-9809784 Glauser & Ahmadi Clarkson University Presently Particle Image Velocimetry (PIV) measurement cannot be experimentally obtained at sufficiently high sample rates due to bandwidth limitation with pulsed YAG lasers (15 Hz or less typically). This poses a problem when dealing with high Reynolds number flows and, in particular, with time dependent and temporally evolving flows if more than just snapshots of the flow are required. The objective of this research is to develop and fine tune a technique that is based on two-dimensional (2-D) Spatial Linear Stochastic Estimation (LSE) which will provide a solution to the low sample rate problem. The method combines the outstanding temporal bandwidth characteristics of hot-wires with the superb spatial resolution of the PIV. The instantaneous velocities are measured via hot-wire anemometry at a few optimally selected points in space, simultaneous velocities are then estimated at the remaining spatial positions where the correlations, obtained from the PIV measurements, are known. This new and important technique can be developed to its fullest potential at Clarkson University. In addition, the PIV system will add a much needed capability to the Experimental Turbulence Laboratory and will impact several current and future major experimental research projects.