Author(s): Sebastian Rubbert
Linked Author(s):
Keywords: Large-eddy simulation; Finite element method; Solid wallboundary conditions
Abstract: In order to accurately model wall friction effects in Large-Eddy simulations of turbulent flow on relatively coarse meshes, the universal law of the wall may be used. It yields correct wall shear stresses that can be incorporated into the model as Neumann boundary conditions. In combination with the Finite Element method, however, this technique leads to physical inconsistencies. For two different solid wall boundary condition concepts based on the universal law of the wall, these inconsistencies are discussed. A modified approach that partly remedies these inconsistencies is implemented into the Finite Element code PASTIS-3D whose “mixed model” Large-Eddy turbulence closure scheme is designed for flow simulation in lakes and reservoirs. An example of turbulent channel flow is chosen for model verification. The results demonstrate that the boundary condition approach, combined with the specific turbulence closure, accurately reproduces the profiles of mean flow and turbulent fluctuations near solid model boundaries.
Year: 2001