Partial cavity instabilities


This paper reviews some of the literature on partial cavity instabilities on single hydrofoils and then summarizes the striking differences in the appearance and behavior of partial cavities on swept foils (as opposed to two-dimensional, unswept foils) as rcently highlighted by de Lange et al. (1994) and Laberteaux and Ceccio (1998). These demonstrate the importance of the spanwise evolution of the re-entrant jet, and the consequences for the characteristics of the cavity closure flow. It is suggested in this paper that several variants of this evolution can be seen in the photographs of cavitation on single hydrofoils foils and on propellers. What is common to many of these variants is that, the spanwise evolution of the cavity and the re-entrant jet can give rise to conditions at some particular spanwise location(s) which initiate partial cavity instability. In this paper we present information on an instability that was observed to occur on a cavitating propeller of modern US Navy design. Detailed photographic examinations show that the instability oscillations involve spanwise development of a re-entrant jet and behavior similar to that of the partial cavity oscillations previously observed on two-dimensional foils

    Similar works