Commun. Comput. Phys., 7 (2010), pp. 683-717. |
Computer Experiments on Rapidly Rotating Plane Couette Flow Mustafa Barri ^{1*}, Helge I. Andersson ^{1} 1 Fluids Engineering Division, Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.Received 22 April 2009; Accepted (in revised version) 17 July 2009 Available online 12 October 2009 doi:10.4208/cicp.2009.09.068 Abstract The turbulence in plane Couette flow subjected to system rotation is investigated. The anti-cyclonic rotation rate is well above the range in which roll-cells occur and close to the upper bound, beyond which no stationary turbulent states of motion exist. The mean velocity profile exhibits a linear region over 80% of the cross-section, in which the mean absolute vorticity is driven to zero. Viscous effects still prevail in narrow regions next to the walls, whereas the quasi-homogeneous central core exhibits abnormal anisotropies of the Reynolds stress tensor, the vorticity tensor and the energy dissipation rate tensor. In spite of the distinctly higher turbulence level observed, a 13% drag reduction is found. This paradoxical finding is ascribed to configurational changes in the turbulence field brought about by the system rotation. AMS subject classifications: 76M12, 76F10, 76F65, 76U05 Notice: Undefined variable: pac in /var/www/html/issue/abstract/readabs.php on line 164 Key words: Turbulence, plane Couette flow, system rotation, anti-cyclonic rotation, anisotropy tensor, zero absolute mean vorticity. *Corresponding author. Email: mustafa.barri@ntnu.no (M. Barri), helge.i.andersson@ntnu.no (H. I. Andersson) |