A short explanation about Particle Image Velocimetry

PIV is an experimental technique to analyze images for obtaining a velocity field from a fluid flow (gas or liquid) that has been seeded with small tracer particles or smoke. Though, it also may be applied for transportation and deformation analyses of (solid) surfaces. It correlates small samples at identic location from one or two images, mostly by using FFT techniques. This results into an estimation of the mean displacement of the tracer particles that are lying within the sample area of the image. As the image magnification factor and the timing between the image recordings are known, these displacament estimators may directly be transformed to an estimator of the local velocity. A set of image samples (also called interrogation area's) that are positioned on a (rectangular) grid, then, result into a velocity field of the fluid flow. In this way the coherent structures of a (turbulent) flow may be observed quantitatively. A more extended explanation about PIV and related techniques with references can be found at Wikipedia.

Gerber van der Graaf
email: gerber_graaf AT users DOT sourceforge DOT net

Last modified: Mon Nov 17 09:41:11 CET 2008