What Is Particle Image Velocimetry?

Particle image velocimetry is a method of recording the position of particles in a flow field with multiple cameras, and analyzing the captured images to measure the flow velocity. The basic principle is to distribute tracer particles in the flow field, and use a pulsed laser sheet light source to enter the measured flow field area. After two or more consecutive exposures, the particle image is recorded on a negative or a CCD camera. Optical Young's fringe method, auto-correlation method or cross-correlation method were used to process the image recorded by PIV film or CC point by point to obtain the flow field velocity distribution. Because of different recording equipment, it is also called FPIV (using film for recording) and digital image velocimetry DPW (using CCD camera for recording). ^[1]

Turbulence, complex flow, unsteady flow and other phenomena have always been

Particle image velocimetry is a new flow measurement technology developed on the basis of traditional flow display technology using graphic image processing technology. It combines the advantages of single-point measurement technology and display measurement technology, and overcomes the weaknesses of the two measurement technologies. It not only has the accuracy and resolution of single-point measurement technology, but also can obtain the overall structure and instantaneous display of the plane flow field. State image. ^[1]

Particle image velocimetry, as a basic method for studying various complex flow fields, has been widely used in various flows, from steady flow to unsteady flow, low speed flow to high speed flow, single-phase flow to multi-phase flow, which is very suitable. It is used to study complex flow structures such as vortex and turbulence, and can also be applied to cutting-edge sciences such as particle velocimetry and image velocimetry.