IL112016A - Planing boat with a bow hydrofoil - Google Patents

Description

Planing boat with a bow hydrofoil ZELIK SEGAL, ALEXANDER SEGAL PLANING BOAT WITH A BOW HYDROFOIL The arrangement belongs to sphere of shipbuilding, in particular - to ships with dynamical support on water by motion.

A partial or total lifting of the hull over the water during the ship motion, by means of hydrofoils or planing, leads to a large decrease of water resistance and to increase of the maximum speed by 2 - 3 times.

However, planing boats (gliders) on a sea-way have an unsteady position, and the passangers feel unadmissably great overloads. The hydrofoil crafts in order to a stable motion on the sea-way are equipped with complicated and expensive ^systems, controlling the angles of attack of the bow and stern hydrofoils; besides that, for securing the necessary submersion of the screws, a great angle of inclination of propeller shaft or complicated transmissions of the main engine power to the propeller are used.

The suggested planing boat with a bow hydrofoil has the adventages of the above-mentioned ships and is devoid of their drawbecks. At the bow extremity of the vessel is arranged a deep submerged wing, equipped with an original and simple sel f regulat ion system. The bottom of stern extremity is supplied with an original well streamlined ledge.

Thanks to the bow wing and to the stern ledge, by arriving at the definite speed, the bow and middle parts of the hull move steadyly above sea-way surface, while the stern extremity planes on the water by a small inclination of propeller shaft and with a necessary submersion of the screw.

Description of the arrangement is explained by the drawing Fig. 1 - side view of the ship; Fig. 2 - cross-section of the ship with a view on the wing constru tion; Fig. 3 - vertical longitudinal section of the wing's post.

The ship 1 is supplied in bow extremity with a wing arrangement, including: the posts 2, to which a horizontal wing 3 is attached; the incl ned wings 4, which are immovable relatively the ship and based by their lower ends on the posts 2 and by the upper ends - on the posts 5. Vertical plates 6 are fastened to the wing 3. Each plate 6 is joined to the post 2 by means of an immovable hinge 7, located near the wing's nose, with a possibility of turning the wing 3 about a horizontal axis. The hinge Θ, located near the wing's tail, joins the plate 6 with a vertical rod 9, the upper end of which is located in a cylinder 10, fastened to the hull of ship 1. In the cylinder lO is located a spring 11, the upper end of which is immovable, and the lower end has a possibility of vertical movement by the turning the wing 3 about the hinge 7.

The highfc of the cylinder 10 corresponds to preliminary compression of the spring 11 with a force equ l to a lift force, which the wing 3 has at a speed 0.5 - 0.6 of the maximum speed of the ship.

As shown in Fig. 1, the stern part of the ship's bottom is supplied with a wedgical ledge 12, the planing lower surface 13 of which forms an acute angle = 3 - ° with a base plane of the ship. The hight of the wedge in its front has not less than spacing & = 10 '. of the ship breadth.

The arrangement works in the following way: In time of stand, the ship 1 is supported on water only by buoyancy forces and has a maximum draught. By motion of the ship 1, the hydrodynamic lift forces^ arising on the hydrofoils and on the planing surface 13, are proportional to their area, angle of attack and square of speed.

By the speed, equal to 50 - 60 '/. of the maximum speed, the bow and middle parts of the hull move above the water surface and the stern extremity planes on it.

The further increase of speed and of lift forces on the wing 3 leads to the further compression of the spring 11, in consequence of that the wing 3 turns about the hinge 7, and the angle of attack. °( of the wing 3 decreases. Therefore the increase of the lift force on the wing 3 almost ceases.

The lift forces of the inclined surf ce-pier ng wings 4 and of the ledge 12 are also sel fregulated ones because by increase of the speed they rise from water and their active submerged parts decrease.

In consequence, by the maximum speed of the ship 1, the bow and middle parts of the hull move on a definite hight above the water, what protects them from touching with waves of a definite amplitude. And the above-mentioned shape of stern extremity permits the ship to have a small running trim, a sm ll inclination of propeller shaft and a sufficient submersion of the screw. 0 The accepted limitations of the angle and spacing > are grounded by that, that the lower limits of the quantities are the minimum ones for securing the necessary lift of the moving ship above the water; and by - 6 - 8" the resistance of water to movement of the ledge 12 heavy increases.

Claims (2)

1. Planing oa-t with a bow hydrofoil, c h a r a c t e r i z e d thereby, that in order to effective regulating the lift force of the hydro oil in dependence on speed of the vBtsoel , the hydrofoil is supplied with vertical plates, everyone of which is fastened by means of a first hinge to an immovable vertical post - with a possibility of turning the hydrofoil about a transversal axis of the ship, and by means of a second hinge - to a vertical rod, resting against a lower end of a spring, the upper end of the spring is immovable relatively the ship.

2. The boat according to claim 1, c h a r a c t e r i z e d thereby, that in order to securing the stable motion of the ship in sea-way conditions, to decreasing the running trim and inclination of propeller shaft, the ship's bottom in its stern part is supplied with a wedgical ledge, the hight of which in the front is not less than 0.1 from ship breadth, and the lower surface of the ledge forms an angle of 3 - 6 degree with a base plane of the ship. Authors: Z. Segal / A. Segal /