Implementation of Johnson-King turbulence model

The non-equilibrium turbulence model developed by Johnson and King, 1985, is implemented in the general purpose flow solver EllipSys2D. this model involves solution of an ordinary differential equation, along the line of maximum Reynolds shear stress and it demonstrates a good performance for separated flow.

The derivation of the model is described and the model is validated on the flow over a flat plate and flow around a NACA0012 airfoil, a NACA4412 airfoil, and the ONERA A-airfoil. For the NACA0012 airfoil a grid refinement study is carried out in order to obtain grid independent results. Finally, lift and drag curves are computed for the NACA0012 airfoil and comparisons with the algebraic Baldwin-Lomax, and two two-equation #kappa# - #omega# turbulence models and experimental data are shown.

The results show that the Johnson-King model improves the prediction of adverse pressure gradients and mildly separated flows compared with the algebraic Baldwin-Lomax model. (au) 1 tabs., 23 ills., 18 refs..