Baldwin-Lomax model
From CFD-Wiki
The Baldwin-Lomax model is a two-layer algebraic model which gives the eddy-viscosity, , as a function of the local boundary layer velocity profile.
| (1) |
Where is the smallest distance from the surface where is equal to :
| (2) |
The inner region is given by the Prandtl - Van Driest formula:
| (3) |
Where
| (4) |
| (5) |
| (6) |
The outer region is given by:
| (7) |
Where
| (8) |
and are determined from the maximum of the function:
| (9) |
is the intermittency factor given by:
| (10) |
is the difference between maximum and minimum speed in the profile. For boundary layers the minimum is always set to zero.
| (11) |
Model constants
The table below gives the model constants present in the formulas above. Note that is a constant, and not the turbulence energy, as in other sections. It should also be pointed out that when using the Baldwin-Lomax model the turbulence energy, , present in the governing equations, is set to zero.
26 | 1.6 | 0.3 | 0.25 | 0.4 | 0.0168 |
References
- "Thin Layer Approximation and Algebraic Model for Separated Turbulent Flows" by B. S. Baldwin and H. Lomax, AIAA Paper 78-257, 1978