Particle Image Velocimetry

We will develop Particle Image Velocimetry PIV as a viable turbulence research tool at a near-wall flow facility glycerin tunnel. The PIV technique is used to study the influence of controlled disturbances on the fluid structure in the very near wall region and compare these results with those from an ongoing LDA study. A PIV system may be conveniently separated into two parts an image acquisition system and an image interrogation system. The image acquisition system is now operational, while the image acquisition system is still under development. The system consists of a small Helium-Neon laser and the associated optics needed for picture illumination and transformation, an x-y traversing system for accurate slide positioning during interrogation, a CCD camera and an image monitor. The interrogation system optically transforms a laser illumination image and then uses a Youngs fringe pattern based technique to analyze the image and reconstruct the velocity field. This interrogation system is tied to a Swan 386 microcomputer and established that all the hardware and software functions properly.