TURBULENT-FLOW PAST AN ARRAY OF BLUFF-BODIES ALIGNED ALONG THE CHANNEL AXIS

Computations and measurements of time mean velocities, total fluctuati on intensities, and Reynolds stresses are presented for spatially pel ionic flows past an array of bluff bodies aligned along the channel ax is. The Reynolds number based on the channel hydraulic diameter and cr oss-sectional bulk mean velocity, the pitch to rib-height ratio, and t he rib-height to channel-height ratio were 2 X 10(4), 10, and 0.13, re spectively. The unsteady phase-averaged Navier-Stokes equations were s olved using a Reynolds stress model with wall function ann wall-relate d pressure strain treatment to reveal the feature of examined unsteady vortex shedding pow. Laser Doppler velocimetry measurements were perf ormed to measure the velocity field. Code verifications were performed through comparisons with others' measured developing single-rib pow a nd our measured fully developed rib-army flow. The possible causes for the differences between the experiments and computations are discusse d The calculated phase-averaged flow field clearly displays the vortex shedding behind the rib and is characterized in terms of shedding Str ouhal number vortex trajectory, vortex celerity, and vortex travelling distance in a phase cycle. Furthermore, the difference between the co mpleted developing single-rib flow and fully developed rib-array pow i s addressed.