Comparison of Eddy-Viscosity Turbulence Models in Flows with Adverse Pressure Gradient

Abstract

Results of computations of aerodynamic flows with attached and separated boundary layers with adverse pressure gradients are presented. The objective is to compare the predictive accuracy of 11 eddy-viscosity turbulence models frequently employed for computing aeronautical flows. The turbulence models considered are the algebraic model of Baldwin and Lomax; the one-equation model of Spalart and Allmaras along with two additional variants of it; six different k, w models; and the nonlinear eddy-viscosity model of Wallin and Johansson. Starting with a boundary-layer flow with a nominally zero pressure gradient, flows with a successively increased adverse pressure gradient are investigated. Computational results are compared with each other and to experimental data. It is found that the agreement between computational and experimental results varies between the turbulence models also for the simpler flow cases. Predictive accuracy obtained with a given model for a given flow case varies between the different flow variables evaluated. The best turbulence model changes from flow case to flow case. Models using transport equations for the eddy viscosity (or a related quantity) typically show better response to a pressure gradient than the algebraic Baldwin-Lomax model. However, no general conclusion on which model to use for adverse-pressure-gradient flows is drawn.