Simultaneous measurements of surface spanwise waves and velocity in a turbulent boundary layer

Abstract

Among the different passive and active techniques for skin friction drag reduction for turbulent boundary layers, near wall forcing through moving walls is one of the most promising techniques at low Reτ. Fewer studies have looked at the mechanism at high Reτ, closer to flight conditions, largerly because, in this regime, numerical simulations become harder and experiments more challenging. To that end, there is the need of a systematic study for different surface waves and flow conditions. A new model using a kagome lattice is presented. It will be tested in the 10x5 wind tunnel at Reτ ≈ 8000. This work introduces an experimental setup which combines simultaneous measurements of surface displacement and velocity in the boundary layer. Here the results from a shorted version of the model at Reτ ≈ 1000 are presented to demonstrate the capability of the experimental setup.