Publications Details
Time-resolved pulse-burst tomographic piv of impulsively-started cylinder wakes in a shock tube
Lynch, Kyle P.; Wagner, Justin W.
Time-resolved tomographic particle image velocimetry measurements of the vortex organization in cylinder wakes at Reynolds numbers from 8,200 to 53,000 is presented. Flow is generated in a shock tube, providing an impulsive starting condition followed by approximately uniform flow conditions for 8.0 msec. A pulse-burst laser and four high-speed cameras enable time-resolved measurements at 10 kHz for the entire test duration; approximately 90 volumetric velocity fields are acquired for each shot. The high energy provided by the pulse burst laser allows for a large measurement volume exceeding most other time-resolved experiments in air. The work demonstrates the feasibility of time-resolved tomographic PIV of large volumes in high-speed air flows, and its utility for maximizing data acquisition in a transient facility. The latter is particularly useful for quantifying the behavior of impulsive flows. A single-image self-calibration procedure is demonstrated to accommodate facility vibrations, and an uncertainty analysis of the measurement is performed. The initial wake development and transition to regular Kármán shedding in the cylinder wake is analyzed in terms of the vortex topology and associated spatial scales as a function of time.