Session Cj - Experimental Techniques.
ORAL session, Sunday, November 23
310, Moscone Center
A Particle Image Velocimeter has been developed for the measurement of field velocity spectra. The velocity spectra is computed from the velocity autocorrelation function, which is obtained by correlating corresponding velocity fields at variable time delays. The PIV system features a single microcomputer that controls the dual Kodak ES1.0 camera arrangement, and is capable of acquiring up to 128 image pairs, per camera, at a maximum frame rate of 30 Hz. The system also synchronizes a pair of dual Nd-Yag lasers for the flow illumination. Using this system field and pointwise spectra have been obtained and compare very well with those obtained by means of Hot Wire Anemometry. The special requirements in the PIV velocity measurement accuracy as well as the system's limitations due to quantization noise are discussed.