Isogeometric Variational Multiscale Large-Eddy Simulation of Fully-developed Turbulent Flow over a Wavy Wall
TEXAS UNIV AT AUSTIN INST FOR COMPUTATIONAL ENGINEERING AND SCIENCES
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We report on the isogeometric residual-based variational multiscale VMS Large Eddy Simulation of a fully developed turbulent flow over a wavy wall. To assess the predictive capability of the VMS modeling framework, we compare its predictions against the results from direct numerical simulation DNS and, when available against experimental measurements. We use C1 quadratic B-spline basis functions to represent the smooth geometry of the sinusoidal lower wall and the solution variables. The Reynolds number of the flow considered is 6,760 based on the bulk velocity and average channel height. The ratio of amplitude to wavelength alphalambda of the sinusoidal wavy surface is set to 0.05. The computational domain is 2 lambda x 1.05 lambda x lambda in the streamwise, wall-normal and spanwise directions, respectively. Mean averaged quantities, including velocity and pressure profiles, and the separationreattachment points in the recirculation region, are compared with DNS and experimental data. The turbulent kinetic energy and Reynolds stress are in good agreement with benchmark data. Coherent structures over the wavy wall are observed in isosurfaces of the Q-criterion and show similar features to those previously reported in the literature. Comparable accuracy to DNS solutions is obtained with at least one order of magnitude fewer degrees of freedom.
- Fluid Mechanics