Imaging optics - Import export

The particle image velocimetry (PIV) is an optical noninvasive working flow velocity measurement method. The flow field is made visible by introducing into the fluid small buoyancy neutral particles – the so called tracers. The particle flow then is illuminated with the aid of a light sheet and recorded at two defined different times within a small time interval with a digital camera. Because the particle move within this time interval with the flow, one can calculate the particles velocity by knowing its path between the two moments of illumination. The result is a velocity vector field of the flow. Here, we assume that the particles are small and follow the flow without any slip. Compared to local methods like LaserDopplerVelocimetry (LDV) with the ParticleImageVelocimetry one can reconstruct a whole flow region An extension of ParticleImageVelocimetry is the combination of PIV with thermometry (PIV/T).