Instantaneous Velocity Vector Maps
Particle Image Velocimetry (PIV) is an optical measurement method used to obtain instantaneous velocity measurements in fluids.
The fluid is seeded with micron sized tracer particles which follow the flow dynamics. These particles are then illuminated via a pulsed laser so that the particles are visible. The motion of the particles between two light pulses is captured via a CCD camera and processed to calculate the displacement and velocity of the flow being investigated.
This method is non-intrusive and can produce two dimensional or even three dimensional vector fields.