Modification of a turbulent boundary layer by circular cavities

It is shown how well-chosen perforations in a wall flow can locally reduce skin friction drag by modifying the generation of bursts boundary layer. For this purpose, detailed hot wire layer experimental investigation past perforated plate, complemented with large eddy simulations, carried out and compared to smooth case. The plate obtained an array flush-mounted circular cavities. These cavities are disposed periodic staggered arrangement. three tested velocities, momentum thickness-based Reynolds number varies from [Formula: see text] 3380 cavity diameter spacing units, respectively, 250 1075, latter being identical both spanwise streamwise directions. mean velocity profiles evidence thickening viscous sublayer decrease as application Variable Interval Time Averaging technique highlights upward shift attenuation average burst intensity duration. Spanwise measurements overall despite lack uniformity. three-dimensional (3D) topology arising simulations provides for qualitative similarities between current setup oscillations.