Flow tagging velocimetry using caged dye photo-activated fluorophores

The use of caged dye photo-activated fluorophore velocimetry is described a nd representative examples are presented. After a brief survey of recently reported measurements, a more detailed example of the Row produced in a cyl inder with a single rotating end wall is presented. Simultaneous stereoscop ic image sets in the (r, z) and (r, theta) planes have been obtained oc er a Reynolds number range of roughly 10(2)-10(5). At low Reynolds numbers (si milar or equal to 0-2000), the steady, axisymmetrical flow is found to quan titatively agree with predictions from a numerical Row solver At higher Rey nolds numbers (from 5 x 10(3) to 10(5)), the now develops considerable turb ulent three-dimensional structure.