Time-resolved two-dimensional concentration measurements in an acoustically driven flow

A nonintrusive optical technique for making simultaneous time-resolved concentration measurements at 10,000 points within a plane intersecting an acoustically forced axisymmetric jet is described. The technique, which involves the pulsinig of a laser synchronously with an acoustic perturbation, is similar to a method developed for two-dimensional mapping of concentrations using a single laser pulse. Different scattering mechanisms, including Lorenz/Mie scattering and fluorescence, have been used for mapping the concentration distributions of large-scale structures in forced axisymmetric jets.