Stereo Particle Shadow Velocimetry

An extension of planar particle shadow velocimetry (PSV) to obtain stereoscopic measurements is presented. PSV is a measurement technique comparable to particle image velocimetry (PIV), the difference being the method of flow field illumination. Pulsed LEDs are used for backlighting in PSV, whereas a laser sheet is used in PIV. PSV is a useful alternative to PIV when there is not optical access for a laser sheet while also providing improved safety and reduced cost. The planar method of PSV has been proven a viable substitute for PIV in 2-component measurements, but the method has not yet been benchmarked for 3-component measurements, such as in stereoscopic imaging. A comparison of stereo PIV and stereo PSV is presented for flow from a simple round jet. The jet was situated in-line with the focal plane (flowing parallel to the laser sheet) and off the focal plane flowing through the laser sheet, thus giving a measurable third component of velocity.