Real-Time Signal Processing in Particle Image Velocimetry

Abstract

Many researchers require whole field velocity data with high spatial and temporal resolution to obtain new experimental information about the flow fields of interest. Thus PIV, Particle Image Velocimetry, is becoming a preferred technique. In the literature, many implementations of PIV systems are described. However, a key point in which systems differ is in the time required from image capture to presentation of the corresponding vector map — the processing time. For practical use this potential time bottleneck can be reduced substantially by very fast processing. Thus the focus of the paper is on the camera-illumination control-processing combination for real time PIV measurements. The seeding, laser and illumination light sheet are only briefly mentioned as these are components that are generally available.

In this paper, key parameters for successful PIV measurements will be related to the benefits of using a real time processor that allows on-line access to the PIV vector maps. Possibilities for quickly optimizing a set-up are shown. The immediate benefits are shorter experimental time, reduced running costs and the possibility of quickly analyzing long data series for comparison of results with conventional point measurements such as CTA and LDA as well as with CFD.