Modeling > Modeling Turbulence > Using Reynolds Stress Transport Turbulence > What Are the Reynolds Stress Transport Models? > What Is the Linear Pressure Strain Model?

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What Is the Linear Pressure Strain Model?

The linear pressure-strain model of Gibson and Launder [46] uses a classic approach to modeling the pressure-strain term, splitting it up into a slow (return-to-isotropy) term, a rapid term, and a wall-reflection term. The node of this model has its own properties.

This is implemented with both a high- wall treatment (that is, using wall functions) and a two-layer approach.

Linear Pressure Strain 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.

Linear Pressure Strain 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.

     

C1

The coefficient , see Eqn. 305.

     

C1w

The coefficient , see Eqn. 307.

     

C2

The coefficient , see Eqn. 306.

     

C2e

The coefficient , see Eqn. 302.

     

C2w

The coefficient , see Eqn. 310.

     

Cl

The coefficient , see Eqn. (12-139).

     

Cmu

The coefficient , see Eqn. 298

     

FwMax

The coefficient , see Eqn. 308.

     

Buoyancy Production of Dissipation

Determines how the coefficient in Eqn. 301 is calculated.

 

None

Neglects the term .

 

Boundary Layer Orientation

Computes according to Eqn. 196.

 

Thermal Stratification

Computes according to Eqn. 195.

     

Sarkar

The coefficient , see Eqn. 303.

     

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_e

The coefficient , see Eqn. 302.

     

Sigma_k

The coefficient , see Eqn. 308.

     

Tdr 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.

     

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

     

Use Boussinesq Approximation

Instead of using the divergence of the computed Reynolds-stress tensor, use the Boussinesq approximation given by Eqn. 239.

 

Ticked

Use Boussinesq approximation.

 

Cleared

Use computed Reynolds stresses.

     

Wall Reflection Term

Include or omit the wall-reflection terms and (see Eqn. 304).

 

Ticked

The terms are included.

 

Cleared

The terms are omitted.

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