Particle image velocimetry measurements of turbulent flows in rotating square ribbed ducts

This paper investigates the flow characteristics along a ribbed square duct using time-resolved particle image velocimetry. The Reynolds number, defined by main velocity (1.82 m/s) and hydraulic diameter (80 mm), is 10 000. rotation numbers are 0, 0.13, 0.26, 0.39, 0.52. blockage aspect ratios of 0.1 1, respectively. As number increases, recirculation zone on suction side becomes larger, reattachment point moves downstream. opposite behavior observed pressure side, this trend develops duct. Furthermore, between different pairs ribs vary greatly at same number. For downstream ribs, stream pattern deflected more to where both extreme region shear stress larger than side.