Advanced Turbulence Modeling For Complex Flows
CRAFT Tech has efforts underway to develop advanced turbulence models within a RANS based framework. Extensions to the two equation k-epsilon turbulence model include the following: Explicit Algebraic Stress Models (EASM) to account for non-equilibrium effects, corrections to account for compressibility effects in high speed flows, anisotropy effects in the dissipation rate (ADRM model), variable Prandtl number model (Prandtl number as a function of the local flowfield).
For unsteady turbulent flows a one equation LES model which tracks the evolution of the subgrid kinetic energy has been implemented. For large scale unsteady problems, a hybrid LES-RANS model is under development which provides a unified grid dependent turbulence model framework which devolves to a RANS model in the limit of coarse resolution and yields a consistent LES/DNS model in the limit of high resolution. The transition is accomplished through the dynamic evaluation of the local turbulence length scale in relation to the local grid scale.
Turbulence Modeling Activities at CRAFT Tech
- EASM Extensions
- Scalar Fluctuation Equations
- Variable Prt/Sct Models
- Turbulent Combustion PDF Models
- Evaluation of Passive Mixing Enhancement Concepts
- Hybrid RANS/LES framework
- Active Control of Cavity Pressure Oscillations using POD Framework
