Discussion: “The Path to Predicting Bypass Transition” (Mayle, R. E., and Schulz, A., 1997, ASME J. Turbomach., 119, pp. 405–411)

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

“…Correlation-based models [17,18] reformulate widely used transition correlations [19] into coefficients of transport equations for the intermittency [20,21] and other transition parameters, to obtain local, and recently [22] Galilean invariant, transition models. Physics-based models [23][24][25] generally rely on the concept [26] of laminar (pre-transitional) kinetic energy k L ≈ 1 2 u 2 (essentially streamwise, in agreement with transition physics [27] and with the observed rapid increase of the Reynolds-stress tensor anisotropy in very low Reynolds number channel flows [28]), which is computed by a specific transport equation, to trigger and control transition in the turbulence model. Transport-equation based transition models are quite successful in mimicking transitional flow effects and in detecting transition [16].…”