RU2371347C1 - Disk-type-foilcraft - Google Patents

Abstract

FIELD: ship building.

SUBSTANCE: invention relates to ship building, particularly to partially submerged disks-type-foil craft. Disks-foils are mounted at an angle of attack and feature V-shape cross section. Blades are fitted on shaft jointed to disk face and having the length that makes the distance between blade rotation plane and disk face equal at least four widths of disks (foils). It seems expedient to make aforesaid disks hydraulically rough or with radial ribs.

EFFECT: higher hydrodynamic lift and reduced hydrodynamic losses.

2 cl, 4 dwg

Description

The invention relates to shipbuilding and can be used in the construction of ships with hydrodynamic support forces and freely rotating disks (wings). The essence of the invention is to increase the lifting force of the disco wings and reduce losses by increasing the speed of the disks

The invention relates to shipbuilding, in particular to high-speed vessels on partially displaced V-shaped disks (wings) freely rotating in bearings in a cross section and installed at an angle of attack α to the incoming flow. The design of such a vessel is described in US patent No. 4061104 A (IPC B63B), published 06.12.1977.

. Срыв циркуляционного потока приводит к тому, что судно с вращающимися дисками глиссирует, то есть, во-первых, гидродинамические силы поддержания действуют лишь на нижние поверхности дисков и, во-вторых, увеличиваются волновое и брызгообразующее сопротивления.The disadvantage of a vessel with freely rotating disks is the small hydrodynamic lifting force due to disruption of the circulation flow due to the very small relative elongation λ of the wing and the insufficient speed of the disks. In fact, the length l of the wetted surface of the disco wing is always less than its width b, i.e.

. Disruption of the circulation flow leads to the fact that a vessel with rotating disks glides, that is, firstly, the hydrodynamic forces of support act only on the lower surfaces of the disks and, secondly, the wave and spray resistance increase.

Preservation of the circulation flow is possible due to an increase in the rotational speed of the disks to such a value that the wetted boundary layer of the liquid maintains the vortex flow by viscous forces. To do this, it is necessary to make drives from the blades with screw surfaces, which are possible, for example, on shafts that are coaxially mounted with each disk. Helical blades are elements of the propeller blades. In the oncoming flow, the blades operate in turbine mode and give rotational energy to the circular discs.

Figure 1 shows the main view of the ship on disco wings with blades. Figure 2 is a section along aa; figure 3 is a section along BB; figure 4 is a section along BB.

In the drawings are indicated: 1 - ship hull; 2 - disks (wings); 3 - half shafts; 4 - blades; 5 - ribs from the upper discharged side of the disk; 6 - ribs from the lower pressure side of the disk; 7 - shaft; 8 - shaft flange.

b is the width of the disco wing;

l is the length of the disco wing;

l ₁ - the distance from the end of the disk to the plane of rotation of the shaft blades;

β is the angle of inclination of the disk;

α is the angle of attack;

φ is the step angle of the turbine blade;

e _c - arrow deflection of the disk;

h is the height of the ribs;

T - disc immersion.

The vessel on the disco-wings (Fig. 1 and Fig. 2) has a hull 1 to which four half-axles 3 are rigidly attached so that the disks 2 (Fig. 3) mounted on the bearings form angles of attack α (Fig. 4) and tilt angles β. Flanges 8 of shafts 7 are coaxially attached to the ends of the disks 2, on which screw blades 4 are installed with a step angle φ = (20 ... 45) degrees. If the disks (wings) are installed at the angle of attack α, then the screw blades at the step angle φ, which consists of the angle of attack of the blade and the angle of the tread, taking into account the slipping of the blade. The distance l _{1 of the} plane of rotation of the blades to the end of the disk should be at least four of its thicknesses, since at lower values of l ₁ there is a violation of the flow around. The exact values of the stepping angles depend on the speed of the vessel and the size of the blades and can be determined by model tests. The number of blades should be at least 6 based on the condition that at least one of the rotating blades was constantly in the fluid flow.

With the initial movement of the vessel on disco-wings in swimming mode, the water resistance will be greater than that of an equal vessel on classical hydrofoils, since the disks in the submerged state have worse hydrodynamic parameters: a large area and a larger frontal section. With increasing speed of the ship on the disco-wings and the hull with half shafts coming out of the water in the “hump” mode, partially submerged disks begin to rotate thanks to the blades, forming a running wetted surface, which leads to the formation of a stable circulation flow around the wetted surface of the disk (Fig. 4) and increased hydrodynamic lift. The magnitude of the lifting force from the blades is very small, since the blades rotate in the "backward" mode. Their purpose is to create additional torque for the discs to form a stable vortex around their wetted part. Therefore, turbine blades can be made of an approximate profile (cylindrical or flat) and from an elastic material, for example, rubber.

If hydrofoil-smooth wings are used on ships with hydrofoils, then on ships with disco wings, the discs must be roughened or with radially spaced ribs 5 and 6 (FIGS. 1 and 2) to entrain fluid and better circulation flow. The height of the ribs h should be no more than the arrow deflection of the disk e _c so as not to disturb the shape of the vortex.

Rotating disco-wings with elastic blades will allow the vessel to overcome small obstacles in the form of flooded wood and other floating objects, since when faced with obstacles, the elastic blades will deform without breakage. In addition, the ship on disco-wings and elastic blades can be rolled out on a prepared shore for sediment and repair.

Claims (2)

1. A vessel on partially displaced discs (wings) freely rotating in bearings mounted with angles of attack and having a V-shape in cross section, characterized in that the blades are mounted on a shaft that is coaxially connected to the end of the disc and has such a length that the distance between the plane of rotation of the blades and the end face of the disk is not less than four thicknesses of the disks (wings). 2. The vessel according to claim 1, characterized in that the disks are hydraulically roughened or with radially spaced ribs.

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