PARTICLE IMAGE VELOCIMETRY - STATUS AND TRENDS

Particle image velocimetry (PIV) is presently attracting quite a lot of interest. PIV allows fluid velocities across a region of a flow to be measured at a single instant in time and is thus an alternative to the conventional hot-wire and laser anemometry, which measure a velocity-time record at a single point in space. This paper discusses the PIV technique as a fluid mechanics tool by comparison to other flow image processing methods and standard laser anemometry. Any implementation of the PIV technique offers a number of technical challenges that must be overcome before the method is truly useful as a measurement technique for fluid mechanics. These problems are reviewed, and work in progress to overcome or circumvent them is reported. The status of PIV is considered by reviewing some selected state-of-the-art applications, and the trends for future developments are discussed. The main emphasis is on the description of methods of processing the PIV images and on a discussion of the practical limitations of PIV as regards measurable velocities, obtainable accuracy, and spatial resolution.