Turbulence, Heat and Mass Transfer 5 K. Hanjali´ c, Y. Nagano and S. Jakirli´ c (Editors) DNS and Wavelet Analysis of a Turbulent Channel Flow Rotating about the Streamwise Direction T. Weller 1 , K. Schneider 2 , M. Oberlack 1 , and M. Farge 3 1 Department of Mechanical Engineering, Chair of Fluid Dynamics, Technische Universit¨ at Darmstadt, Petersenstr. 13, 64287 Darmstadt, Germany, weller@fdy.tu-darmstadt.de , office@fdy.tu-darmstadt.de 2 Laboratoire de Mod´ elisation et Simulation Num´ erique en M´ ecanique, CNRS et Universit´ es d’Aix-Marseille & CMI, Universit´ e de Provence, 39 rue Fr´ ed´ eric Joliot-Curie, 13453 Marseille, France, kschneid@cmi.univ-mrs.fr 3 Laboratoire de M´ et´ eorologie Dynamique, CNRS et Ecole Normale Sup´ erieure, 24 rue Lhomond, 75231 Paris, France, farge@lmd.ens.fr Abstract — In this contribution a study of a turbulent channel flow rotating about the streamwise direc- tion is presented by using direct numerical simulation (DNS). The theory giving a theoretical basis for the mean flow is based on the investigations of [9] employing symmetry group theory. It was found both in DNS and in the theory that a cross flow in the spanwise direction is induced. Statistical evaluations have shown that all six components of the Reynolds stress tensor are non-zero. A series of DNS has been conducted at Reynolds number Re τ = 180 for both the non-rotating case and different rotation numbers up to Ro = 20 to examine the effects of rotation. Further a wavelet analysis has been performed for selected data sets computations to identify and extract coherent vorticities. 1. Introduction Rotating turbulent flows play an increasing role in engineering applications such as in gas tur- bine blade passages, pumps and rotating heat exchangers to name only a few. In these cases secondary flows are induced caused by centrifugal or Coriolis forces. x 1 x 2 x 3 Ω 1 u 1 u 3 Figure 1: Sketch of the flow geometry of a turbulent channel flow rotating about the mean flow direction