ABSTRAKT

Time-resolved digital particle image velocimetry (PIV) system, which includes single-plane (SP) and two-component (2C) PIV, SP-3C PIV, dual-plane (DP) -2C PIV and DP-3C PIV, has been developed using high-repetition-rate Nd:YAG lasers for industrial processing and high-speed CMOS cameras. The developed system was applied to velocity measurements of a turbulent jet and a swirl-stabilized combustor. It is shown that velocity measurement up to 26.7 kHz is possible and the results clearly show the dynamics of turbulence structure. Accuracy of several PIV algorithms such as a spatial-temporal filter method, a 2-step hierarchical method and a window-offset method have been shown for the time-resolved measurement by comparing with DNS and a hot wire measurement. The time-resolved stereoscopic PIV can provide energy spectra of three velocity components in a single plane or in dual planes with small distance and the time-averaged feature of turbulent flows with high accuracy. This system is potentially applicable to the cases with repetition rate from several hundreds Hz to several tens kHz, and would contribute to the advancement of turbulence research in near future.