Algebraic Nonlocal Transition Modeling of Laminar Separation Bubbles Using k − ω Turbulence Models

摘要

Algebraic transitional extensions for the accurate computation of laminar separation bubbles are developed for use with k - omega models. The transitional model. based on integral boundary-layer parameters and transition criteria, introduces streamwise-variable weighting of the production terms in the k - omega equations and delay of the shear-stress-limiter activation. Calibration to fit available DNS data yields satisfactory results for a flat-plate reference case, for both skin-friction and velocity profiles. Ills shown that the model can be adapted to different k - omega variants by appropriate calibration of coefficients. The model is then validated for two airfoil test cases, for both very low and higher Reynolds numbers, a NACA 0012 airfoil at chord-based Reynolds number Re-c = 10(5) and angle-of-attack alpha = 10.55 deg and an S809 airfoil at Re-c = 2 x 10(6) and alpha = 1 deg. For both application cases, comparison with available data is satisfactory.