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2D Backward Facing Step Validation Case
Wilcox2006-klim-m Model Results
Link to Wilcox2006-klim-m equations
Previously on this page the results were reported as Wilcox2006-klim solutions, but more properly they should be referred
to as Wilcox2006-klim-m. Essentially no difference is expected.
Note that thorough
grid studies were not performed for validation cases such as this one.
Some effort was made to ensure reasonable grid resolutions, but there may still be
small noticeable discretization errors. Therefore, these validation results shown should be considered
representative, but not "truth."
Wilcox2006-klim-m results from
CFL3D and FUN3D for ReH=36,000 are shown on
the second-finest grid (257x257, 97x257, 385x449, 129x449).
(Note that Cp values have been shifted so that Cp is close to zero near x/H=40.)
Both CFL3D and FUN3D used freestream turbulence intensity=0.061% and freestream turbulent viscosity (relative to laminar)=0.009
(additional details can be found in the CFL3D User's Manual, Appendix H).
Please read note 5 on Notes on running CFD page.
Note that for this particular case the Wilcox2006-klim-m model does not converge readily to a steady-state result when using
this code on this refined grid.
However, when run time-accurately, the solution settles down and becomes reasonably steady (quasi-steady).
Reattachment is predicted near x/H = 6.8.
Note that these are compressible code results at "essentially incompressible" conditions of M=0.128.
There may be a very small influence of compressibility.
Cp experimental data and CFD results have been shifted so that Cp is approximately 0 near x/H=40 (see brief
discussion on Backward Facing Step Validation Intro Page).
The data files from the quasi-steady CFL3D results are given here:
backstep_cfl3d_cp_w06.dat,
backstep_cfl3d_cf_w06.dat,
backstep_cfl3d_vel_w06.dat,
backstep_cfl3d_uv_w06.dat.
(Note: the profiles have been interpolated using Tecplot software onto pre-set points, that may or may
not correspond to the actual grid points or grid cells used in the computation.)
A typical CFL3D input file is:
backstep_cfl3d_typical_w06.inp.
A typical FUN3D input file is:
fun3d.nml_typical_w06_timeaccurate.
Note that this model is currently assigned
MRR Level 2 for the purposes of this website.
This is because at this time the TMBWG has results for this model
from two different codes from the same home organization.
The results on this page are therefore not necessarily
reliable until additional independent code(s) can be used to verify the model implementation.
Jump to: SA Results,
SSTm Results,
SST-Vm Results,
K-kL-MEAH2015m Results,
EASMko2003-S Results,
K-e-Rt Results Return to: Backward Facing Step Validation Intro Page Return to: Turbulence Modeling Resource Home Page
Recent significant updates: Responsible NASA Official:
Ethan Vogel
09/08/2014 - added cfl3d data files
Page Curator:
Clark Pederson
Last Updated: 03/12/2025