Four turbulence models are evaluated for transonic separated flows usi
ng two well-established solvers, one upwind and one central difference
. The equilibrium model of Baldwin-Lomax predicts separated-now shock
locations too far aft, The effects of several modifications to the hal
f-equation model of Johnson-King are explored in detail, and different
versions of the model are compared. Good results for two- and three-d
imensional flows can be obtained using two different versions of this
model. The one-equation models of Baldwin-Barth and Spalart-Allmaras p
erform well for airfoil flows, but can predict the shock too far forwa
rd at the outboard stations of a separated wing. The effects of numeri
cal truncation error are assessed using grid-refinement studies in com
bination with varying the numerical dissipation levels in both codes.