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 c(μ) coefficient for the calculation of the eddy-viscosity (henceforth labelled NL-c(μ)), provide satisfactory results for transonic buffet flows. The computations also reveal that the Spalart-Allmaras one-equation model provides comparable results to the NL-c(μ) models, while larger inaccuracies are introduced by linear and non-linear models based on constant c(μ) coefficient. Moreover, the buffet onset boundaries are similarly predicted by the one-equation and NL-c(μ) 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.