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Weekly Seminar: Fall 2007

Date: September 21st
Time: 11:00 AM
Location: Maryland Hall 110
Speaker: Dr. Han Seo Ko
Sungkyunkwan University
Title: "Analysis of Three-Dimensional Density Distributions for Unsteady Flow Using Visualization Technique"

Abstract

Velocity and density distributions of a high-speed and starting jet flow have been analyzed simultaneously by a developed three-dimensional digital speckle tomography and a particle image velocimetry (PIV). Two high-speed cameras have been used for the tomography and one for the PIV since a shape of a nozzle for the jet flow is not axi-symmetric and the starting flow is fast and unsteady. The speckle movements between no flow and CO2 jet flow have been obtained by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays for density gradients. The three-dimensional density fields for the high-speed CO2 jet flow have been reconstructed from the deflection angles by the real-time tomography method, and the two-dimensional velocity fields have been calculated by the PIV method simultaneously and instantaneously.