摘要:
A flow control mechanism, for improving pressure resistance and hull vibration, includes a lower fin and an upper fin. The lower fin is disposed between a second station and a fourth station in a length direction of a ship and between 10% and 20% of a design draft from a bottom of the ship in a height direction of the ship, the lower fin being inclined at an angle of 20 to 40 degrees with respect to a design draught (or base) line. The upper fin is disposed between the second station and the fourth station in the length direction of the ship and between 30% and 60% of the design draft from the bottom of the ship in the height direction of the ship, the upper fin being inclined at an angle of 10 to 30 degrees with respect to the design draught (or base) line. Further, an additional fin is disposed between a first station and a third station in the length direction of the ship and between 5% and 20% of the design draft from the bottom of the ship in the height direction of the ship, the additional fin being inclined at an angle of 10 to 40 degrees with respect to the design draught (or base) line.
摘要:
A boat stabilizer that is attachable to the anti-cavitation plate or other structure of the lower drive unit of a boat motor without permanently modifying the structure of the anti-cavitation plate or other structure is provided. The shape and size of the boat stabilizer causes the stabilizer to effectively harness and control the thrust energy generated by the propeller resulting in improved thrust and fuel efficiency. Due to various features, the drag associated with the boat stabilizer is kept to a minimum. Finally, decals and other decorative elements are integrally embedded into the top surface of the inventive boat stabilizer using in-mold decoration (“IMD”) technology which makes the elements resistant to ultra-violet light, virtually indestructible and highly appealing. A boat motor, a method of attaching a boat stabilizer to a boat motor and a method of molding a boat stabilizer having at least one decorative element integrally embedded in the top surface thereof are also provided.
摘要:
A marine propulsion apparatus includes an anti-cavitation plate on a casing that supports a propeller. A lift generation plate, which generates lift during propulsion, is disposed at a position rearward of the casing and above the anti-cavitation plate and extends in a width direction of a hull. The lift generation plate is mounted on the casing via a stay.
摘要:
A marine outboard drive that is equipped with integrated splash plates and a baffle plate that prevent water splash-up along the drive shaft housing. The baffle plate protrudes from the drive shaft housing to interact with plates on the lower bracket to create a labyrinth effect. The labyrinth created by the splash and baffle plates impedes the path of any water impinging upon the lower bracket and the drive shaft housing. This minimizes the amount of water travelling up the drive shaft housing. A splash plate may also be included on the lower bracket to minimize water flow above the lower bracket.
摘要:
This invention relates to a device for use with a ducted propeller system r suppressing gap cavitation between a moving rotor tip and duct wall and more particularly to means for supplying fluid to a ducted propeller whereby cavitation or the noise resulting therefrom may be eliminated.
摘要:
The invention is directed to an apparatus for attaching to a wing operating in a fluid medium for increasing the angle of attack at which the wing experiences aerodynamic/hydrodynamic stall. The wing includes upper and lower surfaces extending between a leading edge and a trailing edge and having a maximum thickness therebetween, and between a root and a tip, wherein the leading and trailing edges define a chord and the root and tip define a span. The apparatus comprises at least one substantially triangular shaped plate member projecting normal to the upper surface of the wing. The at least one plate member has a straight top surface and a curvilinear bottom surface which corresponds to the contour of the upper surface of the wing. The top and bottom surfaces define the height of the at least one plate member and extend in a substantially chordwise direction between an anterior end and a posterior end of the at least one plate member. The at least one plate member has its minimum height at the anterior end and its maximum height at the posterior end wherein the maximum height corresponds to a fully attached boundary layer thickness of a fluid flowing over the upper face, the boundary layer thickness determined at the trailing edge at a predetermined operating condition.
摘要:
A marine propeller using the circulation control principle of blowing tantially over a Coanda surface at the trailing edge of each blade to develop high blade lift (thrust). Each blade has internal chambers and two blowing slots so that blowing is controllable for forward and for reverse thrust without reversing rotational direction of the propeller. This propeller is capable of generating much greater thrust and ship speed at lower RPM and noise levels than conventional propellers.
摘要:
A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). An upper adaptor spool (48) has a lower threaded outer portion (50) mating with a threaded portion (46) of the vertical bore (26) of the drive housing (20) and supporting the upper gear (42) for rotation about the driveshaft (36) and supporting the driveshaft (36) for rotation within the adaptor spool (48). Vertical bore structure enables assembly from above of the majority of the vertical drive train components into a one-piece unitary integrally cast housing. The vertical distance between the adaptor spool (48) and the lower bearing (118) supporting the vertical driveshaft (36) is about equal to propeller radius. The lower concentric counter-rotating propeller shafts (156, 158) are spaced from the upper input shaft (28) by a distance along the driveshaft (36) in the range of about 9 to 15 inches.
摘要:
Method and arrangement for the reduction of the resistance to rotation of the propeller (3) of a ship (1) going in ice when the ice increases the resistance to rotation of the propeller to a level higher than when sailing in open water. When the resistance to rotation increases, gas is passed to the propeller (3), and the supply of gas is adjusted when the resistance to rotation is changed. The supply of gas may be continual, but as a rule it is used only for short periods in order to correct the speed of rotation of the propeller to the appropriate level.
摘要:
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.