Direct numerical simulation of open-channel flow in the fully rough regime etc15 Tracking Number 221Presentation: Session: Wall-bounded flows 6 Room: Room B Session start: 10:30 Fri 28 Aug 2015 Marco Mazzuoli marco.mazzuoli@kit.edu Affifliation: Institute for Hydromechanics (IfH), Karlstuhe Institute of Technology (KIT), Karlsruhe, Germany Markus Uhlmann uhlmann@kit.edu Affifliation: Institute for Hydromechanics (IfH), Karlstuhe Institute of Technology (KIT), Karlsruhe, Germany Topics: - Wall bounded flows Abstract: The Direct Numerical Simulation (DNS) of an incompressible open channel flow over a layer of rigid spherical roughness elements fixed on the wall in well-packed square arrangement has been performed which shows values of the Reynolds number Rb ~ 6900 (ks+ ~ 100) and produces a mean velocity defect ∆U+ ~ 7 in the range of the fully-rough regime. First and second moment statistics of the velocity field have been analyzed. The stress distribution as well as the hydrodynamic force and torque acting on the surface of individual roughness elements have been computed. Results are presently shown and compared with those obtained in the context of a previous DNS performed in the transitionally rough regime. |