초록 ▼

A multi-bladed marine propeller designed for efficient operation in intermediate, partially cavitating flow regions between fully cavitating flow and noncavitating flow. Each of the blades has a radially inner subcavitating section and an outer section which is configured to have a higher angle of a

A multi-bladed marine propeller designed for efficient operation in intermediate, partially cavitating flow regions between fully cavitating flow and noncavitating flow. Each of the blades has a radially inner subcavitating section and an outer section which is configured to have a higher angle of attack and tapered trailing and leading edges so that it supercavitates at high speeds either with or without ventilation and subcavitates at low speeds. Various other features of each blade include different length chords on the pressure and suction sides of the outer section and an inclined trailing surface area extending between the chord ends for improved off design, design point, and astern operation. A minimized transition area is included between the inner and outer sections, and narrow chord lengths are provided in the tip area to minimize and balance overall tip section drag. The supercavitating outer section also has positive rake to improve ventilation performance and positive skew to minimize undesirable transition flow. The result is a propeller with improved efficiency at low speeds without degrading the supercavitating section performance at high speed.

대표청구항 ▼

A marine propeller having a hub and a plurality of blades attached to the hub, said blades each comprising a body having a radially inner end connected to said hub and a radially outer tip located radially outwardly from said inner end, said blade body having an inner section adjacent said inner end

A marine propeller having a hub and a plurality of blades attached to the hub, said blades each comprising a body having a radially inner end connected to said hub and a radially outer tip located radially outwardly from said inner end, said blade body having an inner section adjacent said inner end with means for causing said inner section to subcavitate at substantially all rotational speeds and an outer section adjacent said tip, said outer section having a tapered leading edge portion and a tapered trailing edge portion with means for causing said outer section to subcavitate at slow speeds and supercavitate at high rotational speeds.