A wide flat bulbous bow

Abstract

The present invention provides a wide flat bulbous bow, the width of the bulbous bow is greater than the height, the bulbous bow has a side surface and a bottom surface, and on any cross section passing through the bulbous bow, the side surface intersects with the cross section at a first curve, the bottom surface intersects with the cross section at a second curve, and the curvature of the first curve is greater than the curvature of the second curve. The wide flat bulbous bow disclosed by the present invention not only improves the wave-making resistance generated when the ship is sailing, but also increases the specific gravity of the displacement volume distributed in the bow, improves the stability and wave resistance of the ship, is conducive to resisting the heave phenomenon under the action of wind and waves, provides stable working conditions for precision equipment and instruments, and ensures that the ship does not touch the bottom when operating in the extremely shallow water area of ​​4m under wave conditions.

Description

Technical Field

[0001] The invention relates to the field of bulbous bow design, in particular to a wide flat bulbous bow. Background Art

[0002] The bulb bow is also called the "bulb bow", which is a spherical protrusion under the water surface of the bow. It is a structure used to overcome the resistance of the ship. Its size and shape match the hull to offset the pressure of the water, generate smaller waves, and improve the water flow near the hull to reduce the resistance of the ship.

[0003] However, when the ship is sailing or operating in shallow waters, on the one hand, it needs to adapt to the shallow draft environment, and on the other hand, it needs to overcome the impact on the buoyancy of the ship during operation. This requires the hull to have higher stability, and the existing bulbous bow cannot meet this requirement. Summary of the invention

[0004] The present invention provides a wide flat bulbous bow to solve the above problems.

[0005] A wide flat bulbous bow, the width of which is greater than its height, the bulbous bow having a side surface and a bottom surface, in any cross section passing through the bulbous bow, the side surface intersects with the cross section at a first curve, the bottom surface intersects with the cross section at a second curve, and the curvature of the first curve is greater than the curvature of the second curve.

[0006] Furthermore, the bottom surface is smoothly connected to the bottom of the hull, the bottom surface intersects with the mid-longitudinal section at a third curve, and the curvature of the third curve gradually decreases from the bow direction to the stern direction;

[0007] The width of the bottom surface gradually increases from the bow to the stern, and the curvature of the intersection line between the bottom surface and the cross section near the bow is greater than the curvature of the intersection line between the bottom surface and the cross section near the stern.

[0008] Furthermore, there is an angle between the bulbous bow and the hull, and the angle gradually increases from the bow direction to the stern direction.

[0009] Furthermore, the height of the bulbous bow is greater than the designed draft height of the hull, and the height of the bulbous bow gradually decreases from the bow direction to the stern direction.

[0010] Furthermore, the width of the cross-section of the bulbous bow at the perpendicular line of the hull bow is 45%-55% of the hull width, the maximum height of the bulbous bow is 120%±5% of the designed draft height of the hull, and the length of the bulbous bow is 2%±0.5% of the length between the perpendicular lines of the hull.

[0011] The wide flat bulbous bow disclosed in the present invention not only improves the wave resistance generated when the ship is sailing, but also increases the specific gravity of the displacement volume distributed in the bow, improves the stability and wave resistance of the ship, and is conducive to resisting the heave phenomenon under the action of wind and waves. Through CFD simulation, it is found that when the ship faces the waves, under the action of waves with a wave height of 1.5m and a wavelength of 1 times the length of the ship, the hull performs heave motion with an amplitude of 0.12m, and the maximum sinking depth is only 0.24m, which provides stable working conditions for precision equipment and instruments, and ensures that the ship does not touch the bottom when operating in the extremely shallow water area of ​​4m under wave conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a front view of a wide flat bulbous bow disclosed in an embodiment of the present invention;

[0014] Figure 2 It is a longitudinal section view of a wide flat bulbous bow disclosed in an embodiment of the present invention;

[0015] Figure 3 for Figure 2 Medium AA perspective cross-section;

[0016] Figure 4 for Figure 2 Cross-section from the middle BB perspective;

[0017] Figure 5 for Figure 2 Cross-sectional view from CC perspective;

[0018] Figure 6 for Figure 2 Cross-section from medium DD perspective;

[0019] Figure 7 for Figure 2 Cross-section from the middle EE perspective;

[0020] Figure 8 for Figure 2 Cross-section from medium FF perspective;

[0021] Fig. 9 for Figure 2 Cross-section from the middle GG perspective;

[0022] Fig.10The figure is a comparison diagram of the vertical speed change of the ship with the wide flat bulbous bow hull in the embodiment of the present invention and the vertical speed change of the ship without the wide flat bulbous bow hull. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figure 1 As shown, the hull 1 has a wide and flat bulbous bow 2, the width of the bulbous bow 2 is greater than the height, and the bulbous bow 2 has a side surface and a bottom surface. In any cross section passing through the bulbous bow 2, the side surface intersects with the cross section at a first curve 121, and the bottom surface intersects with the cross section at a second curve 122. The curvature of the first curve 121 is greater than the curvature of the second curve 122. The cross section is perpendicular to the bow and stern line of the hull, as shown in FIG. Figure 3-9 As shown, in this embodiment, multiple cross sections are selected for display. Figure 2 As shown, the bottom surface is smoothly connected to the bottom of the hull 1, and the bottom surface intersects with the mid-longitudinal section at a third curve 123, and the curvature of the third curve 123 gradually decreases from the bow direction to the stern direction; the width of the bottom surface gradually increases from the bow to the stern direction.

[0025] like Figure 4 As shown, there is an angle between the bulbous bow 2 and the hull 1, such as Figure 3-6 As shown, the angle gradually increases from the bow direction to the stern direction.

[0026] The maximum height of the bulbous bow is greater than the designed draft height of the hull, and the height of the bulbous bow 2 gradually decreases from the bow direction to the stern direction.

[0027] like Figure 8 As shown, it is a cross-sectional view at the perpendicular line of the bow of the hull. The width of the cross-sectional view of the bulbous bow 2 at the perpendicular line of the bow of the hull is 45%-55% of the hull width, the maximum height of the bulbous bow 2 is 120%±5% of the designed draft height of the hull, and the length of the bulbous bow 2 is 2%±0.5% of the length between the perpendicular lines of the hull.

[0028] The bottom of the hull 1 is a plane, and the port side and the starboard side of the hull 1 are perpendicular to the bottom of the hull. The Fourier number of the hull is 0.170-0.180, the block coefficient is 0.9-0.99, and the design draft is 2.4m-3m.

[0029] A hull with a large square coefficient will greatly increase the risk of the hull hitting the bottom in shallow waters when the hull rises and falls too much with the waves, which can easily cause damage. The bulbous bow provided in this embodiment greatly reduces the height of the hull rising and falling with the waves. The flat wide bulbous bow weakens the waveform below the designed waterline and reduces the wave resistance. Not only does it reduce the degree of hull fluctuation under waves, but it also increases the volume of water that can be displaced by the hull, making the hull draft further shallower.

[0030] The bulbous bow in this embodiment not only improves the wave resistance generated when the ship is sailing, but also increases the proportion of the displacement volume distributed in the bow, thereby improving the stability and seakeeping of the ship, and is conducive to resisting the heave phenomenon under the action of wind and waves. Fig.10 As shown, the bulbous bow performance is verified by CFD calculation. The darker curve in the figure is the shallow draft geophysical exploration vessel in this embodiment, and the shallower curve is the ordinary ship type, which does not have the bulbous bow in this embodiment. It can be clearly seen from the figure that the vertical speed of the shallow draft geophysical exploration vessel in this embodiment is small, that is, the up and down fluctuations are small. Under the action of waves with a wave height of 1.5m and a wavelength of 1 times the length of the ship, the hull performs a vertical swing motion with an amplitude of 0.12m, and the maximum sinking depth is only 0.24m, which provides stable working conditions for precision equipment and instruments, and ensures that the ship does not touch the bottom when operating in the extremely shallow water area of ​​4m under wave conditions.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide flat bulbous bow, characterized in that: The width of the bulbous bow is greater than its height, the bulbous bow has a side surface and a bottom surface, in any cross section passing through the bulbous bow, the side surface intersects with the cross section at a first curve (121), the bottom surface intersects with the cross section at a second curve (122), and the curvature of the first curve (121) is greater than the curvature of the second curve (122); The width of the bottom surface gradually increases from the bow to the stern; The bulbous bow is used for shallow draft conditions.

2. A wide flat bulbous bow according to claim 1, characterized in that: The bottom surface is smoothly connected to the bottom of the hull, the bottom surface intersects with the mid-longitudinal section at a third curve (123), and the curvature of the third curve (123) gradually decreases from the bow direction to the stern direction; The curvature of the intersection line between the bottom surface and the cross section in the direction close to the bow is greater than the curvature of the intersection line between the bottom surface and the cross section in the direction close to the stern.

3. A wide flat bulbous bow according to claim 1, characterized in that: An included angle is formed between the bulbous bow and the hull, and the included angle gradually increases from the bow direction to the stern direction.

4. A wide flat bulbous bow according to claim 1, characterized in that: The height of the bulbous bow is greater than the designed draft height of the hull, and the height of the bulbous bow gradually decreases from the bow direction to the stern direction.

5. A wide flat bulbous bow according to claim 1, characterized in that: The width of the cross section of the bulbous bow at the perpendicular line of the hull bow is 45%-55% of the hull width, the maximum height of the bulbous bow is 120%±5% of the designed draft of the hull, and the length of the bulbous bow is 2%±0.5% of the length between the perpendicular lines of the hull.

Images