An algebraic transition model for fluid flows

Abstract

An algebraic (zero-equation) transition model is developed to capture multiple transition mechanisms. The newly devised algebraic transition model is parameterized using “flow-structure-adaptive” variables and coupled with the truncated Spalart-Allmaras (SA) turbulence model. The intermittency factor γ relies on “local flow information” and is directly linked to the “vorticity-based production” term of the SA model. Splitting γ into lower and higher regimes of the “free-stream turbulence intensity” enhances the model coefficient calibration and predictions of various phenomena (“natural, bypass, separation-induced, wake-induced”, etc.) encountered in transitional flows. Simulations approve that the new formulation provides good correspondence with other transition models, available in the literature.