|October 20, 2013, 12:07||
Mesh size for turbulence boundary layer
Join Date: Mar 2011
Posts: 6Rep Power: 7
I have several questions regarding mesh resolution for turbulence modeling.
1. What’s the mesh resolution required to solve a turbulence boundary layer with RANS?
2. What’s the mesh resolution required to solve a turbulence boundary layer with LES?
3. How does result look like if the mesh resolution is not enough(in Fluent)?
4. If wall function is applied, what the required resolution then? How many grids do I need inside the viscous sublayer and buffer layer? What grid growth rate is recommended?
5. Is the wall function for LES different from the standard wall function for RANS?
6. In LES simulation, what happens if no wall function is applied and near-wall mesh is not fine enough?
7. For modeling flow over several bluff body, there are typically flow separation, adverse pressure gradients, and wake interaction. Is wall function still valid in this case?
8. What’s recommended the mesh resolution for the free shear region (far from the wall) with LES and RANS?
I appreciate your help!
|October 20, 2013, 15:19||
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 2,920Rep Power: 34
too many questions for being answered in a brief post....
just consider that "resolving" the boundary layer means that you have enough points in the range y+ = 0..5. In principle, this is valid fore DNS/LES and often can be a guideline also for RANS.
Wall models must be different for LES and RANS since different is the meaning of the variable resolved.
|Thread||Thread Starter||Forum||Replies||Last Post|
|Number of cells in mesh don't match with size of cellLevel||colinB||OpenFOAM Native Meshers: snappyHexMesh and Others||11||January 13, 2015 12:47|
|An error has occurred in cfx5solve:||volo87||CFX||5||June 14, 2013 17:44|
|Low Mixing time Problem||Mavier||CFX||5||April 29, 2013 00:00|
|2D Mesh Generation Tutorial for GMSH||aeroslacker||Open Source Meshers: Gmsh, Netgen, CGNS, ...||12||January 19, 2012 04:52|
|fluent add additional zones for the mesh file||SSL||FLUENT||2||January 26, 2008 12:55|