Particle image velocimetry measurements of smooth- and rough-wall turbulence from the SAFL Atmospheric Boundary Layer wind tunnel

Wall-bounded turbulent flows under smooth- and rough-wall surface conditions were measured using particle image velocimetry (PIV) in the Atmospheric Boundary Layer Wind Tunnel at St. Anthony Falls Laboratory (SAFL), University of Minnesota. In the rough-wall case, the tunnel surface was covered with woven wire mesh. The smooth- and rough-wall conditions were each measured for two free-stream velocities (7 m/s and 10 m/s), totaling four flow cases. The friction Reynolds number in the four cases ranges from 3,800 to 14,000. In each case, the PIV imaging field was oriented in the streamwise–wall-normal plane. To enhance the spatial resolution, the measurement field was positioned in the lowest 10 cm of the boundary layer, capturing the roughness sublayer and logarithmic region in the rough-wall cases. Separate high-frequency hotwire anemometer measurements of the full boundary layer profile were used to estimate the scaling parameters such as the boundary layer thickness. This dataset includes the processed velocity vector fields from the PIV measurements and the key scaling parameters.