### 16.2.2. Variables Relevant for Turbulent Flows

The following table contains a list of variables (with both long and short variable names) that can be used when working with turbulent flows. For an explanation of the column headings, see List of Field Variables.

A B in the Type column indicates that the variable contains only non-zero values on the boundary of the model.

Long Variable Name | Short Variable Name | Units | Availability | Definition
--- | --- | --- | --- | ---
Blending Function for DES model | desbf | [ ] | 2 C, M, R, TS | Controls blending between RANS and LES regimes for the DES model
Turbulence Kinetic Energy | ke | [m^2 s^-2] | 1 A, C, M, P, R, TS | For details, see The k-epsilon Model in the CFX-Solver Modeling Guide.
Turbulence Eddy Dissipation | ed | [m^2 s^-3] | 1 A, C, M, P, R, TS | The rate at which the velocity fluctuations dissipate. For details, see The k-epsilon Model in the CFX-Solver Modeling Guide.
Turbulent Eddy Frequency | tef | [s^-1] | 1 A, C, M, P, R, TS |
Eddy Viscosity | eddy viscosity | [kg m^-1 s-1] | 2 A, C, M, P, R, TS | The “eddy viscosity model” proposes that turbulence consists of small eddies that are continuously forming and dissipating, and in which the Reynolds stresses are assumed to be proportional to mean velocity gradients. For details, see Eddy Viscosity Turbulence Models in the CFX-Solver Theory Guide.
Reynolds Stress | rs | [m^2 s^-2] | 2 A, C, M, P, R, TS | This is a tensor quantity with six components. For details, see Statistical Reynolds Stresses in the CFX-Solver Modeling Guide and Reynolds Stress Turbulence Models in the CFX-Solver Theory Guide in the ANSYS CFX documentation.
Statistical Reynolds Stress uu | rsstat uu | [m^2 s^-2] | 3 M, R | In LES runs, Reynolds Stress components are automatically generated using running statistics of the instantaneous, transient velocity field. For details, see Statistical Reynolds Stresses in the CFX-Solver Modeling Guide.
Statistical Reynolds Stress vv | rsstat vv | [m^2 s^-2] | 3 M, R
Statistical Reynolds Stress ww | rsstat ww | [m^2 s^-2] | 3 M, R
Statistical Reynolds Stress uv | rsstat uv | [m^2 s^-2] | 3 M, R
Statistical Reynolds Stress uw | rsstat uw | [m^2 s^-2] | 3 M, R
Statistical Reynolds Stress vw | rsstat vw | [m^2 s^-2] | 3 M, R
Velocity Correlation uu | uu | [m^2 s^-2] | 3 C, M, R | These variables represent the instantaneous velocity correlation and are used in the first term on the right hand side of Equation 4–10 in the CFX-Solver Modeling Guide.
Velocity Correlation vv | vv | [m^2 s^-2] | 3 C, M, R
Velocity Correlation ww | ww | [m^2 s^-2] | 3 C, M, R
Velocity Correlation uv | uv | [m^2 s^-2] | 3 C, M, R
Velocity Correlation uw | uw | [m^2 s^-2] | 3 C, M, R
Velocity Correlation vw | vw | [m^2 s^-2] | 3 C, M, R
Yplus | yplusstd | [ ] | 2,B C, R, TS | A variable based on the distance from the wall to the first node and the wall shear stress. For details, see Solver Yplus and Yplus in the CFX-Solver Modeling Guide.
Solver Yplus | yplus | [ ] | 2,B C, R, TS | A deprecated internal variable. For details, see Solver Yplus and Yplus in the CFX-Solver Modeling Guide.

Release 18.2 - © ANSYS, Inc. All rights reserved.