Particle Image Velocimetry

In particle image velocimetry (PIV), velocity measurements are taken by analysing the displacement of small particles in fluid flow between successive exposures of a laser light sheet. The entire light sheet is stored with each recording. This allows snapshots to be captured quickly and averaged in large numbers according to the degree of turbulence, enabling mean values and turbulence levels to be determined. The following image shows a stereoscopic PIV measurement taken at our institute and discussed as an example of an application in the textbook on particle image velocimetry.