# SST k-omega model

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+ | The SST k-omega turbulence model [Menter 1994] is a [[Two equation turbulence models|two-equation]] [[Eddy viscosity|eddy-viscosity]] model which has become very popular. The SST formulation combines the best of two worlds. The use of a k-omega formulation in the inner parts of the boundary layer makes the model directly usable all the way down to the wall through the visous sub-layer, hence the SST k-omega model can be used as a [[Low-Re turbulence model]] without any extra damping functions. The SST formulation also switches to a k-epsilon behaviour in the free-stream and thereby avoids the common k-omega problem that the model is too sensitive to the [[Turbulence free-stream boundary conditions|inlet free-stream turbulence properties]]. Authors who use the SST k-omega model often merit it for its good behaviour in adverse pressure gradients and separating flow. The SST k-omega model does produce a bit too large turbulence levels in regions with large normal strain, like stagnation regions and regions with strong acceleration. This tendency is much less pronounced than with a normal k-epsilon model though. | ||

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==Kinematic Eddy Viscosity == | ==Kinematic Eddy Viscosity == | ||

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## Revision as of 09:51, 31 May 2007

The SST k-omega turbulence model [Menter 1994] is a two-equation eddy-viscosity model which has become very popular. The SST formulation combines the best of two worlds. The use of a k-omega formulation in the inner parts of the boundary layer makes the model directly usable all the way down to the wall through the visous sub-layer, hence the SST k-omega model can be used as a Low-Re turbulence model without any extra damping functions. The SST formulation also switches to a k-epsilon behaviour in the free-stream and thereby avoids the common k-omega problem that the model is too sensitive to the inlet free-stream turbulence properties. Authors who use the SST k-omega model often merit it for its good behaviour in adverse pressure gradients and separating flow. The SST k-omega model does produce a bit too large turbulence levels in regions with large normal strain, like stagnation regions and regions with strong acceleration. This tendency is much less pronounced than with a normal k-epsilon model though.

## Contents |

## Kinematic Eddy Viscosity

## Turbulence Kinetic Energy

## Specific Dissipation Rate

## Closure Coefficients and Auxilary Relations

## References

**Menter, F.R. (1994)**, "Two-equation eddy-viscosity turbulence models for engineering applications", AIAA Journal, vol. 32, pp. 269-289.