High spanwise wall-shear stress events in turbulent duct flow

摘要

The wall-shear stress distribution in turbulent duct flow at a bulk Reynolds number of Re_b=15 400 has been assessed with the micro-pillar shear-stress sensor MPS~3. The flow facility and the sensor are further described in [1, 2]. 12 sensors are used to detect the one-dimensional wall-shear stress distribution. The sensor is mounted at the center plane of the duct. The spatial resolution of the sensor line is 10.8 l~+ (viscous units) and the total field of view of 120 l~+ along the spanwise direction allows to capture characteristic dimensions of the wall-shear stress distribution at sufficiently high resolution. By applying Taylor's hypothesis along the streamwise direction, it is possible to determine the spatial wall-shear stress distribution.