A Tsai’s model based S-PIV method for velocity measurements in a turbulent Ekman layer

This paper reports on laboratory experiments concerning frictional rotating turbulent boundary layers in spin-up flow over a flat horizontal bottom. Three-component velocity fields are obtained by Stereoscopic Particle Image Velocimetry. An original reconstruction algorithm, based on Tsai’s camera model, has been developed on the basis of a linear approximation on the acquisition plane. The new technique, allowing any geometrical camera configuration, is validated using three-dimensional target translation test cases. Velocity measurements are thus performed on the Ekman layer, showing a remarkable agreement with the Ekman theoretical predictions in the laminar regime and providing original data on the turbulent regime.

► A new reconstruction method for S-PIV based on Tsai’s pinhole camera model.
► Method successfully tested on 3D moving target displacement measurements.
► 3D velocity measurements obtained for laminar and turbulent Ekman layers.
► Laminar regime measurements in very good agreement with analytical solutions.
► Modifications of the mean velocity profiles observed in turbulent regime.