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Contradictions in the Large-Wavelength Approximation of Turbulent Flow Past a Wavy Bottom

  • Paolo Luchini
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 165)

Abstract

What’s just barely more complicated than a parallel channel flow? A lightly (and slowly) perturbed parallel channel flow. Yet the properties of turbulence, as extracted from a direct numerical simulation, can be very different. One practical example arises in a widespread geophysical application: the formation of ripples in sand. Common wisdom is to use an eddy-viscosity turbulence model to describe it. Our own work on this problem, started in the same vein years ago, was contradicted by simulations using a volume force to represent the streaming effect of the bottom shape modulation. Now, new simulations using an immersed boundary to represent the actual shape of the wall unfold the contradiction: the scales of length involved are much larger than anticipated.

Keywords

Direct Numerical Simulation Eddy Viscosity Wavy Wall Bottom Shear Stress Sand Ripple 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.DIINUniversità di SalernoFiscianoItaly

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