Applying 3D Viscous/Inviscid Interaction Method to Predict Flows Around Wings and Propellers

In the past, the boundary element method (BEM) has been widely used to predict the potential flow around hydrofoils and propellers. The viscosity, which not only causes friction and reduces the efficiency but also affects the pressure distributions, is considered via an empirical skin friction coefficient. In this paper, the three-dimensional VII method, which coupled a lower order panel method with a two-dimensional integral boundary layer solver (the viscous/inviscid interaction method, or VII) is used to solve the flow around three-dimensional wings and propellers. It is assumed that the boundary layer growth is mainly in the chord-wise direction and simplified the three-dimensional boundary layer equations into two-dimensional. The three dimensional velocities, which is from the panel method, are used as the edge velocities, and the influence of boundary layers in other strips are considered. The pressure distributions and open water characteristics are compared with either full-blown RANS simulations or with existing experimental data, and it is shown that the 3D VII method can improve the results significantly.