Modeling of Flow Transition Using an Intermittency Transport Equation

A new transport equation for intermittency factor is proposed to model transitional flows. The intermittent behavior of the transitional flows is incorporated into the computations by modifying the eddy viscosity, μ t , obtainable from a turbulence model, with the intermittency factor, γ: μ t * =γμ t . Menter's SST model is employed to compute μ t and other turbulent quantities. The proposed intermittency transport equation can be considered as a blending of two models-Steelant and Dick and Cho and Chung. The former was proposed for near-wall flows and was designed to reproduce the streamwise variation of the intermittency factor in the transition zone following Dhawan and Narasimha correlation and the latter was proposed for free shear flows and a realistic cross-stream variation of the intermittency profile was reproduced. The new model was used to predict the T3 series experiments assembled by Savill including flows with different freestream turbulence intensities and two pressure-gradient cases