Abstract
To investigate fine scale structure of turbulent flows, time-resolved dual-plane stereoscopic particle image velocimetry (TRDPSPIV) system has been developed using high-repetition-rate Nd: YAG lasers for industrial processing and high-speed CMOS cameras. This system provides all three velocity components and nine velocity gradients with high spatial and temporal resolution. The developed system was applied to velocity measurements of a turbulent jet. It is shown that probability density functions of the measured nine velocity gradients agree well with those obtained from direct numerical simulation (DNS). From the results of TRDPSPIV, coherent fine scale eddies of turbulence are identified and those characteristics such as diameter and asymmetry are shown.
