engleski

Flow, turbulence and surface pressure on a wall-mounted cube in turbulent boundary layers

The characteristics of the surface pressure on wall-mounted cubes subjected to turbulent boundary layers were experimentally studied in a boundary layer wind tunnel. Two turbulent boundary layers similar to the suburban-type atmospheric boundary layer were created at two different scales using two sets of castellated barrier walls, vortex generators and surface roughness elements. The thickness of these boundary layers was different ; however, in both cases it was ten times greater than the characteristic dimension of the respective cubes. The normalized flow shear at the cube height was the same in both experiments, while the turbulence intensity was different. This fact enabled the pressure characteristics to be studied on a wall-mounted cube based solely on the effect of the incoming turbulence, separately from the flow shear, conditions which had previously proven to be important. In such setup, the differences in pressure characteristics on wall- mounted cubes are substantial. It is demonstrated that the horseshoe vortex has a greater effect on the lower cube half and it scales in the same manner as turbulent boundary layers.

Turbulent boundary layer ; Wall-mounted cube ; Surface pressure characteristics ; Laboratory experiments

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