2013/02/25 by Huisman, Sander G., Scharnowski, Sven, Cierpka, Christian +3
#FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn)
paper · doi:10.48550/arxiv.1302.6081
We provide direct measurements of the boundary layer properties in highly turbulent Taylor-Couette flow up to Ta=6.2 × 1012 using high-resolution particle image velocimetry (PIV). We find that the mean azimuthal velocity profile at the inner and outer cylinder can be fitted by the von Kármán log law u+ = \frac 1κln y+ +B. The von Kármán constant κ is found to depend on the driving strength Ta and for large Ta asymptotically approaches κ≈ 0.40. The variance profiles of the local azimuthal velocity have a universal peak around y+ ≈ 12 and collapse when rescaled with the driving velocity (and not with the friction velocity), displaying a log-dependence of y+ as also found for channel and pipe flows [1,2].