2010 | OriginalPaper | Buchkapitel
The Response of Wall Turbulence to Streamwise-Traveling Waves of Spanwise Velocity
verfasst von : Maurizio Quadrio
Erschienen in: Progress in Turbulence III
Verlag: Springer Berlin Heidelberg
Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.
Wählen Sie Textabschnitte aus um mit Künstlicher Intelligenz passenden Patente zu finden. powered by
Markieren Sie Textabschnitte, um KI-gestützt weitere passende Inhalte zu finden. powered by
Waves of spanwise velocity traveling along the walls of a plane turbulent channel flow are studied by Direct Numerical Simulations. We consider waves of spanwise velocity which are oscillating in time and modulated in space along the streamwise direction.Waves which slowly travel forward produce a large reduction of drag. Faster waves, with a phase speed corresponding to the convection velocity of the turbulent fluctuations at the wall, lock with the convecting near-wall turbulent structures and yield drag increase. Backward-traveling waves, on the other hand, invariably produce a drag-reducing effect. To explain the physical mechanisms involved, the generalized Stokes layer induced by the traveling waves is studied in the laminar regime.