Some Reynolds number effects on two- and three-dimensional turbulent boundary layers

Experimental data for a two-dimensional (2-D) turbulent boundary layer (TBL ) flow and a three-dimensional (3-D) pressure-driven TBL flow outside of a wing/body junction were obtained for an approach Reynolds number based on m omentum thickness of Re-theta = 23,200. The wing shape had a 3:2 elliptical nose, NACA 0020 profiled tail, and was mounted on a flat wall. Some Reynol ds number effects are examined using fine spatial resolution (Delta gamma ( +) = 1.8) three-velocity-component laser-Doppler velocimeter measurements o f mean velocities and Reynolds stresses at nine stations for Reo = 23,200 a nd previously reported data for a much thinner boundary layer at Re-theta = 5,940 for the same wing shape. In the 3-D boundary layers, while the stres s profiles vary considerably along the flow due to deceleration, accelerati on, and skewing, profiles of the parameter 1/S = tau root nu (2) = root(<(u <nu>)over bar>)(2) + (<(<nu>w)over bar>)(2) root nu (2) correlate well and over available Reynolds numbers. The measured static pressure variations on the flat wall are similar for the two Reynolds numbers, so the vorticity f lux and the measured mean velocities scaled on wall variables agree closely near the wall. The stresses vary similarly for both cases, but with higher values in the outer region of the higher Rea case. The outer layer turbule nce in the thicker high Reynolds number case behaves similarly to a rapid d istortion of the flow, since stream-wise vortical effects from the wall hav e not diffused completely through the boundary layer at all measurement sta tions.