Application of the v 2 - f model to aerospace configurations

Reynolds-Averaged Navier-Stokes (RANS) methods have become an important design tool in aerospace industry. Turbulence models, which are required for closure of the RANS equations, are a substantial component in these methods. Several flow regimes exist where the accuracy of flow predictions depends strongly on the turbulence model used. Turbulence has a major influence on the growth rate of boundary layers for flow around airfoils. In subsonic flows at high-lift conditions, strong adverse pressure gradients decelerate the flow. The turbulence intensity in the flow directly affects separation of the flow. In transonic flows the boundary layer growth influences the location of shock waves. Generally, a more rapid growth moves shocks further upstream. Depending on location and strength, a shock may induce separation of the flow. Flow separation strongly affects the lift and drag of an airfoil as a consequence of a change in the circulation around the airfoil. These examples, test cases for which are considered in this report, demonstrate the need for accurate turbulence models. The objective of the present report is to evaluate the v-f model (Durbin 1995) for aerospace applications. Different versions of this model are validated on flow around singleand multi-element airfoils. The flow predictions are compared with experimental data and results obtained with the Spalart-Allmaras (Spalart & Allmaras 1992) and Menter SST (Menter 1993) models. Both models are widely used in aerospace industry. While comparison with experimental data provides a measure for the physicality of the results predicted, the comparison with other turbulence models provides a competitive measure of accuracy.