Hydrodynamic Characteristics of Water-Entry Blades

The partially submerged ventilated propeller (PSVP) is of interest to many researchers and ship builders due to its high propulsive efficiency and thrusting capability at the high sea states. As a matter of fact, it is now used for those ships of high speed up to 50 knots. However, its full capability is not totally utilized to date due to the complex nature of both hydrodynamic and material problems. It is a well known fact that PSVP fails materially after a certain period of time. The cause of the failure is not fully understood to date. Although PSVP is tested in the form of propeller for many years, the detailed ventilation phenomena, i.e., blade entry problems are not fully investigated. The paper presented herein will discuss about the results of blade entry experiments with two-dimensional blades of triangular shape used.