What Is the Menter BSL K-Omega Model?

This problem of sensitivity to free-stream/inlet conditions was addressed by Menter [44], who recognized that the transport equation from the standard K-Epsilon model could be transformed into an transport equation by variable substitution. The transformed equation looks very similar to the one in the standard K-Omega model, but adds an additional non-conservative cross-diffusion term containing the dot product . Inclusion of this term in the transport equation will potentially make the K-Omega model give identical results to the K-Epsilon model. Menter suggested using a blending function (which includes functions of wall distance) that would include the cross-diffusion term far from walls, but not near the wall. His BSL (baseline) model effectively blends a K-Epsilon model in the far-field with a K-Omega model near the wall. Purists may object that the blending function crossover location is arbitrary, and could obscure some critical feature of the turbulence. Nevertheless, the fact remains that Menter's approach cures the biggest drawback to applying the K-Omega model to practical flow simulations.

Properties

Convection	For guidance on selecting a convection, see Diffusion Term .
	1st-order	Selects the first-order convection.
	2nd-order	Selects the second-order convection.

Expert Properties

Unless you are thoroughly familiar with the theoretical aspects of this model and the discretization techniques used in STAR-CCM+, we recommend that you not make any changes within the Expert category. The values in that category reflect both the model's design and discretization approaches that have been optimized for accuracy and performance. Tampering with them may diminish the effectiveness of the model.

Beta1	The coefficient , see Eqn. 284.
Beta2	The coefficient , see Eqn. 285.
BetaStar	The coefficient , see Eqn. 255.
Kappa	The coefficient , see Eqns. (284) and (285).
Normal Stress Term	Determines whether the full Boussinesq approximation used.
	Ticked	The stress tensor is modeled as and production is computed using Eqn. 257
	Cleared	The stress tensor is modeled as and production is modeled using the simplified expression .
Sdr Minimum	The minimum value that the transported variable is permitted to have. An appropriate value is a small number that is greater than the floating point minimum of the computer.
Secondary Gradients	Neglect or include the boundary secondary gradients for diffusion and/or the interior secondary gradients at mesh faces.
	On	Include both secondary gradients.
	Off	Exclude both secondary gradients.
	Interior Only	Include the interior secondary gradients only.
	Boundaries Only	Include the boundary secondary gradients only.
Sigma_k1	The coefficient , see Eqn. 284.
Sigma_k2	The coefficient , see Eqn. 285.
Sigma_w1	The coefficient , see Eqn. 284
Sigma_w2	The coefficient , see Eqn. 285
TkeMinimum	The minimum value that the transported variable is permitted to have. An appropriate value is a small number that is greater than the floating point minimum of the computer.