CN112158308A

CN112158308A - Novel low resistance bilge keel structure of marine auxiliary ship

Info

Publication number: CN112158308A
Application number: CN202011031116.3A
Authority: CN
Inventors: 张新曙; 高天池; 支鹏飞
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2021-01-01

Abstract

The invention provides a novel low-resistance bilge keel structure of a maritime work auxiliary ship, which comprises a conventional bilge keel fixed on a bilge part of a ship body and a plurality of discrete blade-shaped rotatable bilge keels. According to the novel low-resistance bilge keel structure of the maritime work auxiliary ship, parts, which are inconsistent with the surface flow line of a ship body due to the situation, in the conventional bilge keels are removed, and the parts are replaced by a plurality of discrete type bilge keel structures which can rotate in a small angle range; these discrete bilge keels are automatically angled along the flow line while sailing, thereby reducing drag.

Description

Novel low resistance bilge keel structure of marine auxiliary ship

Technical Field

The invention relates to the field of bilge keels, in particular to a novel low-resistance bilge keel structure of a maritime work auxiliary ship.

Background

The design of the conventional fixed bilge keels needs to be arranged along the surface flow line of the ship body under a certain sailing working condition. The parallel middle body of the auxiliary marine craft ship body is short, the sailing and working conditions are complex, and the working conditions of various sailing speeds and various drafts exist. The bilge keels arranged according to a certain working condition are often inconsistent with the surface flow line of the ship body under other working conditions, so that the resistance is increased.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a novel low-resistance bilge keel structure of a maritime work auxiliary ship, which removes the part, which is inconsistent with the surface flow line of a ship body due to the condition, in the conventional bilge keel and replaces the part with a plurality of discrete type bilge keel structures which can rotate in a small angle range; the discrete bilge keel structures automatically adjust the angle along the flow line when sailing, so that the resistance is reduced; under the condition of zero navigational speed, the anti-rolling effect is not influenced basically because the angle range of the adjustment is small (less than 15 degrees); the method has important use value for ships which pay attention to zero-navigation-speed wave resistance and have complicated and changeable navigation conditions, such as wind power operation and maintenance ships, crane ships, scientific research ships and the like in maritime work auxiliary ships.

In order to achieve the above objects, the present invention provides a novel low resistance bilge keel structure of a maritime craft auxiliary ship, which comprises a conventional bilge keel fixed to a bilge of a ship body and a plurality of discrete-type leaf-shaped rotatable bilge keels.

Preferably, the conventional bilge keels are arranged in the middle section of the bilge of the ship body or the part of the conventional bilge keels, which is proved by CFD calculation or model experiments to have no difference in flow lines under various working conditions of the bilge.

Preferably, the discrete-type blade-shaped rotatable bilge keels are arranged on a part of the bilge keels, and flow lines of the discrete-type blade-shaped rotatable bilge keels are different under various working conditions of the bilge keels through CFD calculation or model experiments.

Preferably, each discrete blade-shaped rotatable bilge keel comprises a shaft, two limit bearings, a blade, a gravity balance device and a damping device; the first end of the blade forms a mounting groove, the limit bearing is fixed in the mounting groove, and the shaft is rotatably connected in the limit bearing and fixedly connected with the ship body; the second ends of the blades are arranged towards the direction of the bow of the ship body; the gravity balance device is fixed at the first end of the blade; the damping device is sleeved outside the shaft and arranged between the inner wall of the mounting groove and the shaft.

Preferably, at least one reinforcing rib is arranged inside the shell of the ship body of the connection part of the shaft and the ship body.

Preferably, the blades are streamlined.

Preferably, the material of the blade is steel.

Preferably, the rotatable angle of the limit bearing is less than or equal to 15 degrees.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

by adopting the discrete blade-shaped rotatable bilge keels, the resistance increase caused by the inconsistency of the moving direction and the flow line of the bilge keels under various complex navigation working conditions can be reduced; and the due anti-rolling effect of the bilge keels can be well maintained at zero navigational speed.

Drawings

FIG. 1 is a schematic structural diagram of a low-resistance bilge keel structure of the novel maritime work auxiliary ship according to the embodiment of the invention;

fig. 2 is a schematic structural view of a discrete-type blade-shaped rotatable bilge keel according to an embodiment of the present invention.

Detailed Description

The following description of the preferred embodiments of the present invention, with reference to the accompanying

drawings

1 and 2, will provide a better understanding of the function and features of the invention.

Referring to fig. 1, the novel low-resistance bilge keel structure of the maritime craft auxiliary ship according to the embodiment of the invention comprises a conventional bilge keel 1 fixed to a bilge of a ship body 3 and a plurality of discrete-type blade-shaped rotatable bilge keels 2.

In this embodiment, the conventional bilge keels 1 are arranged at the middle section of the bilge of the ship body 3 or at the portions of the bilge where the flow lines are not different under various working conditions as proved by CFD calculation or model experiments.

The discrete blade-shaped rotatable bilge keels 2 are arranged on the parts of the bilge keels, the flow lines of which are proved to be different under various working conditions of the bilge through CFD calculation or model experiments.

Referring to fig. 2, each discrete-type blade-shaped rotatable bilge keel 2 comprises a shaft 21, two limit bearings 22, a blade 23, a gravity balance device 24 and a damping device 25; the first end of the blade 23 forms a mounting groove, the limit bearing 22 is fixed in the mounting groove, and the shaft 21 is rotatably connected in the limit bearing 22 and fixedly connected with the hull 3; the second ends of the blades 23 are arranged toward the bow direction of the hull 3; a gravity balance device 24 is fixed to a first end of the blade 23; the damping device 25 is sleeved outside the shaft 21 and is disposed between the inner wall of the mounting groove and the shaft 21.

In this embodiment, at least one reinforcing rib is provided inside the hull 3 at the connection portion of the shaft 21 and the hull 3.

The vanes 23 are streamlined.

The blade 23 is made of steel.

The rotatable angle of the limit bearing 22 is less than or equal to 15 degrees.

Referring to fig. 1 and 2, in the low resistance bilge keel structure of the marine auxiliary vessel according to the embodiment of the present invention, the shaft 21 is a fixing device and is welded to the hull 3 through a shroud plate. The shaft 21 extends into the mounting groove of the blade 23. The limit bearing 22 has a limit function, and ensures that the blade 23 rotates within a certain small angle (not more than 15 degrees). The positioning angle of the limit bearing 22 can be determined by the direction range of the streamline at the position according to CFD calculation or model experiment, and an intermediate angle is taken. The limit bearing 22 adopts water lubrication and takes long-time underwater maintenance-free as a design principle. After the blades 23 are installed, the gravity balance device 24 needs to be properly adjusted to keep balance in the sea. Each component needs to be checked for fatigue strength. The blades 23 can be sized appropriately large to enhance roll damping without exceeding the width of the hull 3 and the baseline.

While the present invention has been described in detail and with reference to the embodiments thereof as illustrated in the accompanying drawings, it will be apparent to one skilled in the art that various changes and modifications can be made therein. Therefore, certain details of the embodiments are not to be interpreted as limiting, and the scope of the invention is to be determined by the appended claims.

Claims

1. A novel low-resistance bilge keel structure of a maritime work auxiliary ship is characterized by comprising a conventional bilge keel fixed on a bilge part of a ship body and a plurality of discrete blade-shaped rotatable bilge keels.

2. The novel maritime auxiliary ship low-resistance bilge keel structure according to claim 1, wherein the conventional bilge keel is arranged in the middle section of the bilge of the ship body or a part of which the flow line is not different under each working condition of the bilge proved by CFD calculation or model experiments.

3. The novel maritime work auxiliary ship low-resistance bilge keel structure according to claim 2, wherein the discrete-type blade-shaped rotatable bilge keel is arranged at a part with different flow lines under various working conditions of the bilge part, which is proved by CFD calculation or model experiments.

4. The novel maritime work auxiliary ship low-resistance bilge keel structure according to any one of claims 1-3, wherein each discrete blade-shaped rotatable bilge keel comprises a shaft, two limit bearings, a blade, a gravity balancing device and a damping device; the first end of the blade forms a mounting groove, the limit bearing is fixed in the mounting groove, and the shaft is rotatably connected in the limit bearing and fixedly connected with the ship body; the second ends of the blades are arranged towards the direction of the bow of the ship body; the gravity balance device is fixed at the first end of the blade; the damping device is sleeved outside the shaft and arranged between the inner wall of the mounting groove and the shaft.

5. The novel maritime work auxiliary ship low-resistance bilge keel structure is characterized in that at least one reinforcing rib is arranged inside a shell of a ship body of the connecting portion of the shaft and the ship body.

6. The novel maritime auxiliary ship low-resistance bilge keel structure according to claim 5, wherein the blades are streamlined.

7. The novel maritime work auxiliary ship low-resistance bilge keel structure according to claim 6, wherein the blades are made of steel.

8. The novel maritime work auxiliary ship low-resistance bilge keel structure according to claim 6, wherein the rotatable angle of the limiting bearing is less than or equal to 15 degrees.