Gamma-Re Transition Model

Gamma-Re (γ-Re) transition model is a two equation model used in Computational Fluid Dynamics (CFD) to modify turbulent transport equations to simulate laminar, laminar-to-turbulent and turbulence states in a fluid flow.

The transition model calculated an intermittency factor that creates (or extinguishes) turbulence by slowly introducing turbulent production at the laminar-to-turbulent transition location.

) transition model was to develop a transition model based on local variables which could be easily implemented into modern CFD code with unstructured grids and massive parallel execution.

model needs to know the structure of the boundary layer and the integration along it; both concepts are hard to implement in three dimensions along many subdivisions of a grid.

Another key insight to the formulation of this model is that the Reynolds vorticity number can be related to the Reynolds transition onset number so there is a local way to determine the transition location.

The intermittency acts on the production term of the turbulent kinetic energy transport equation in the SST model to simulate laminar/turbulence flows.