Design of Twisted Cavitating Hydrofoil using a Barotropic Flow

For the design of a twisted hydrofoil in a cavitation tunnel a computational method for simulating three-dimensional cavitating flows is applied. The method is based on the Euler equations for 3D steady flow, which are solved on an unstructured, tetrahedral grid using a finite volume method. A preconditioning method is employed to cope with low-speed flows. The mathematical model is completed by a barotropic law that provides the density as function of the pressure in the cavitating flow.
Using the computational method the design of a twisted hydrofoil is considered featuring a sheet cavity with a triangular shaped planform similar to sheet cavitation occurring on ship propellers. Furthermore, the design calls for the interaction of the sheet cavity with the tunnel walls to be avoided. Numerical results are compared with experimental results obtained in the cavitation tunnel of Delft University of Technology.
The analysis of the upwash and downwash on the hydrofoil due to the vortical wake generated by the twisted hydrofoil is presented by means of Prandtl`s lifiting line theory.