A Free Streamline Theory for 2-Dimensional Fully Cavitated Hydrofoils, T. Yao-Tsu Wu, Undated(0140)
The shape of cavities in two-dimensional, steady super-cavitating flows is discussed. Some new finite cavity models are described; these models feature cavity termination in spiral vortices followed by trailing wakes whose thickness is proportionate to the drag coefficient of the forebody. Linearized theory, together with point forebodies, is used to derive simple relations between drag, cavitation number, and cavity length. The case of a dragless forebody is also considered and the cavity length is shown to depend upon the second moment of the distributed drag. The influence of both longitudinal and transverse gravity fields on the flow past a body producing drag is discussed. It is shown that in all cases the cavity is caused to be finite. In the case of the transverse field, the cavity is shown to be of a length which corresponds to a Froude number of (p)-1/2 and it is, rather surprisingly, deflected over its mid-part in the same direction in which gravity acts.