Numerical simulation of transonic buffet flows using various turbulence closures

The paper presents a numerical investigation of buffet flows using various turbulence models, including linear and non-linear low-Re eddy-viscosity models (EVM). The accuracy of the models is assessed against experimental data for transonic flows around the NACA-0012 aerofoil. The study shows that non-linear two-equation models in conjunction with functional cμ coefficient for the calculation of the eddy-viscosity (henceforth labelled NL-cμ), provide satisfactory results for transonic buffet flows. The computations also reveal that the Spalart–Allmaras one-equation model provides comparable results to the NL-cμ models, while larger inaccuracies are introduced by linear and non-linear models based on constant cμ coefficient. Moreover, the buffet onset boundaries are similarly predicted by the one-equation and NL-cμ models. The study has been performed using a second-order time accurate implicit-unfactored method which solves in a coupled fashion the Navier–Stokes and turbulence transport equations. The spatial discretisation of the equations is obtained by a Riemann solver in combination with a third-order upwind scheme.