Soot-velocity measurements by particle vaporization velocimetry

We demonstrate a new imaging technique for velocity measurements in particl e-laden flows. The technique, particle vaporization velocimetry, is a form of flow tagging based on laser vaporization of absorbing particles at defin ed locations in the flow. The locations of these tagged regions are then in terrogated after a known delay to determine the convective velocity. Result s are presented for vaporization of carbonaceous (soot) particles in a nonr eacting gas jet and a hydrocarbon flame, with interrogation provided by eit her elastic scattering or laser-induced incandescence from the soot. The lo ng lifetime of the tagged soot regions (>2 ms) allows measurements to be ma de over a wide range of velocities. (C) 1999 Optical Society of America.