Evaluation of Turbulence Models with Quadratic Constitutive Relation for Prediction of Wing-Body Juncture Flow

Abstract

The NASA juncture flow experiments were designed for the purpose of evaluating and improving the ability of computational fluid dynamics (CFD) simulations to predict the juncture region flow field of a wing-body configuration. The wind tunnel experiments provide critical information for testing the accuracy of various turbulence models in simulating the complex flow separation that occurs at the trailing edge of the juncture region. The purpose of this paper is to build on the previous CFD research in the literature on juncture region flow with a focus on implementation of a structured hexahedral mesh with lower computing requirements and several turbulence models, in particular the newly developed one equation Wray- Agarwal (WA) turbulence model. The results from the one equation Spalart Allmaras (SA) and Wray-Agarwal (WA) turbulence models as well as the two-equation �� − �� SST (Shear Stress Transport) model are compared with the experimental data. Computations are performed and compared for four angles of attack of -2.5, 0, 5 and 7.5 degree. More importantly, this paper also analyzes the accuracy of various turbulence models with nonlinear quadratic constitutive relation (QCR) for eddy viscosity in comparison to the linear Boussinesq assumption. The prediction of pressure coefficient at various span-wise locations of the wing and the separation bubble near the trailing edge of the juncture demonstrate the ability of the Wray-Agarwal model in accurately computing the wing-body juncture flow field. This is reinforced by prediction of velocity profiles and turbulent shear stresses upstream of the fuselage and near the separation region of the wing.