Near Wall Turbulent Boundary Layer

Kurzfassung

The following PIV application performed in 1996 in a turbulent boundary layer at the wall of a flat plate illustrates two problems: obtaining PIV data close to a wall and recovering PIV data even in a flow with gradients (due to the velocity profile of the boundary layer). In the present series of experiments the measurement position was 2.3 m downstream of a tripping region in the low-turbulence wind tunnel at the DLR-Göttingen research center [17]. At this position the turbulent boundary layer thickness δ was of the order of 5 cm, of which the lower 3 cm was imaged. At free stream velocities of 10.3, 14.9 and 19.8 m/s between 90 and 100 PIV image pairs were recorded. The evaluation of the recordings were made without windows shifting and window deformation which were not available at that time.