A quasi three-dimensional Navier-Stokes method for transonic swept wing flows

摘要

A computational method to predict the viscous transonic flow development around a swept, untapered wing planform is described. ^The Reynolds-averaged Navier-Stokes equations are reduced to a quasi 3D form by assuming infinite swept-wing flow conditions. ^This approach enables the 3D flow around a chordwise 'slice' of the wing to be computed. ^The governing mean-flow equations are solved in conjunction with a one-equation turbulence model, which involves a modeled transport equation for the turbulent kinetic energy and algebraic length-scale formulations. ^The numerical scheme adopted uses a cell-centered, finite-volume spatial discretization together with an explicit, multistage time-stepping scheme to obtain the steady-state solutions. ^A modified outer turbulent length-scale formulation is proposed to reduce the magnitude of the turbulent viscosity coefficient as the boundary-layer flow becomes 3D, in line with experimental observations. ^Results are presented for an unswept and a 28-deg swept RAE 2822 wing section; predictions are compared with available experimental data. ^The computations for the swept RAE 2822 wing section show an improved agreement with measured mean-velocity and cross-flow angle profiles in the boundary layer towards the trailing edge of the wing section using the modified outer length-scale formulation. ^(Author)