PIV measurement of the flow field in rectangular ducts with 60 circle parallel, crossed and V-shaped ribs

The flow characteristics in rectangular ducts with aspect ratio of 1:8 were investigated experimentally using particle image velocimetry to reveal the function of the inclined ribs as turbulators or generators of favorable flows. Circular ribs were attached on the wide walls and the rib height-to-hydraulic diameter ratio was kept as 0.06 with an attack angle of 60degrees. The obtained results showed strong effects of the inclined ribs on the flow behavior by the development of secondary flows. The magnitude of the streamwise velocity component was detected to have spanwise variation. The flow characteristics were correlated with the previous corresponding heat transfer results obtained by the same authors. (C) 2003 Elsevier Inc. All rights reserved.