Prediction of Boundary Layer Transition Based on Modeling of Laminar Fluctuations Using RANS Approach

This article presents a linear eddy-viscosity turbulence model for predicting bypass and natural transition in boundary layers by using Reynolds-averaged Navier-Stokes (RANS) equations. The model includes three transport equations, separately, to compute laminar kinetic energy, turbulent kinetic energy, and dissipation rate in a flow field. It needs neither correlations of intermittency factors nor knowledge of the transition onset. Two transition tests are carried out: flat plate boundary layer under zero and non-zero pressure gradients with different freestream turbulence intensities, and transitional flow over a wind turbine blade at a chord Reynolds number of 3×106. Results are presented in terms of skin friction coefficients. Comparison with the experimental data from both tests evidences a good agreement there is between them.