Particle imaging velocimetry is a laser optical measurement technique. This technique is non-intrusive and is used in research and diagnostics for flow turbulence, microfluidics, spray atomization and combustion processes. It measures the entire region within the flow as its velocity is measured simultaneously.
The basic principle includes photographic recording of the motion of microscopic particles that follow the fluid or gas flow. Image processing techniques are then employed to ascertain the particle motion, the flow velocity, from the photographic recordings. As long as there are enough particles inside the area of flow being examined, the complete velocity field of the flow can be ascertained.
This highlights the differences between particle imaging velocimetry and point measurement methods which use probes to measure flow velocity at a single point. The main benefit of this is that it is a quantitative flow field mapping method. A method which offers physical insight into the complete flow behavior. This technique enables both the extraction of measurement data and the visualization of flow structures.
The standard particle image velocimetry set up is made up of 3 main components. A high-speed camera, a high-power multi-pulsed laser, and an optical arrangement to transform laser output light to a light sheet and a synchronizer. This controls the synchronization of the laser and the camera.