2000 Volume 14 Issue 2 Pages 150-157
This review introduces the laser based measuring technique for both velocity of gas phaseand solid particle with particle sizing. Laser Doppler Velocimetry (LDV) has been the instrument ofchoice for measuring dispersed-and gas-phase velocities in particle-laden flows. LDV was used forsimultaneous measurements of continuous-and dispersed-phase velocities, which permits the particlesize discrimination based on light scattered intensity. Phase Doppler Anemometry (PDA) has beendeveloped for more precise size measurement for spherical particles. For non-spherical particles, diffraction intensity method for the equivalent diameter based on the projection area has been summa-rized. For the detection of particle shape, Shadow Doppler technique has been developed by the exten-sion of the optical system of Laser Doppler Velocimetry. Digital Particle Image Velocimetry (DPIV) is increasingly considered a proven technique for detecting both phases simultaneously. The author's group developed a measurement system to distinguish a dispersed-phase particle from a tracer in fluidflow. Several experimental results are presented in this review for gas-solid two-phase flow, such asjet, mixing layer and wall jet. Mean and Fluctuation velocities of both phases and volume concentra-tion of solids phase are given to make clear the turbulent structure of gas-solid two-phase flow.
