Imaging Measurements of Flow Velocities using Laser-Induced Fluorescence

Imaging velocity measurements along a line through a flowing gas are described. Laser-induced fluorescence from I 2 molecules, used to seed the flow, was utilized. A method of alternating counter-propagating beams from a single-mode dye laser, acting in the wing of the Doppler-shifted molecular absorption profile was used. Some improvements to the technique are also suggested.