A vector scanning processing technique for pulsed laser velocimetry

Pulsed laser sheet velocimetry yields nonintrusive measurement of two-dimensional velocity vectors across an extended planar region of a flow. Current processing techniques offer high-precision (1%) velocity estimates, but can require several hours of processing time on specialized array processors. Under some circumstances, a simple, fast, less accurate (~5%) data reduction technique, which also gives unambiguous velocity vector information, is acceptable. The authors examine a direct space-domain processing technique. It uses a novel data coding and reduction technique, where the particle time history information is used directly. Further, it has no 180° directional ambiguity. A complex convection vortex flow was recorded and completely processed in under 2 min on an 80386 based PC, producing a two-dimensional velocity vector map of the flow field. Using this space-domain vector scanning (VS) technique, pulsed laser velocity data can be reduced quickly and reasonably accurately, without specialized array processing hardware