Numerical simulation of wing vortex generators – methodologies and validation

Abstract

ABSTRACTThis paper presents the results of a study of different Vortex Generator (VG) modelling approaches that have been performed in order to develop a better understanding of the current Computational Fluid Dynamics (CFD) capability to simulate transonic flows where wing-mounted VGs are present.The practicality of using CFD methods commonly employed in the aerospace industry to predict the influence of VGs on wing performance is studied. It is hoped that presenting the experience gained will be of value to aerodynamicists working on similar problems in industry. An approach, using fully resolved, conformal mesh around the VGs, has been investigated through studying Reynolds-Averaged Navier Stokes (RANS) simulations with two alternate turbulence models, the Spalart-Allmaras (SA) model and the Speziale-Sarkar-Gatski (SSG) Reynolds Stress Model. An initial assessment of two alternative VG modelling techniques, use of the Chimera overset meshing and a reduced-order VG model has also been performed. In addition, an investigation of the impact of the wing deformation under aerodynamic loading was conducted. The results obtained were compared with the wind-tunnel measurements acquired in the Aircraft Research Association Transonic Wind Tunnel, using the N47-05 half model with installed VGs.It was observed that the VGs significantly modify the flow behaviour at sufficiently high incidence, which leads to higher lift coefficient values. While the SA turbulence model was unable to capture the complicated nature of the flow when VGs were present, SSG simulations yielded promising results.Each of the VG modelling approaches has shown some strengths and weaknesses. Further study on the subject is suggested in order to develop best practices that can be applied for solutions of industrial-scale problems.