Omega-shaped scissor bow

Abstract

The invention relates to the technical field of ship engineering, in particular to an omega-shaped scissor prow which comprises a streamline submerged body, a rear-tilting lower hull and a front-tilting upper stem post, the lower end of the front-tilting upper stem post and the upper end of the rear-tilting lower hull intersect at one point above a design waterline, the front-tilting upper stem post tilts towards the upper right from the intersection point, and the lower end of the front-tilting upper stem post and the rear-tilting lower hull intersect at one point above the design waterline. The rear-tilting lower ship body tilts to the lower right from the intersection point, and the rear-tilting lower ship body and the rear-tilting lower ship body form'lt; the invention discloses a prow. According to the omega-shaped scissor-shaped stem, through a special structure formed by the streamline diving body, the backward tilting type lower hull and the forward tilting type upper stem post, the resistance performance and the seakeeping effect are remarkable, and meanwhile the omega-shaped scissor-shaped stem has the advantages of being good in resistance performance, small in head wave slapping, smooth in water flow, small in vertical heaving, gentle in pitching, not prone to wave rising on a deck and the like; and the comprehensive technical performance is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of ship engineering, and in particular to an Ω-shaped scissor-type bow. Background Art

[0002] In ship design, there are two mature bow types: one is the traditional forward bow (such as Figure 1 As shown), the second is the emerging rearward-tilted bow (as shown Figure 2 shown).

[0003] The forward-leaning bow is the most widely used due to its simple curved surface structure, easy sheet metal deployment, and balanced overall performance. However, it is subject to strong headwave impact, and the bow has a great risk of structural damage. Moreover, the effective waterline length is often the smallest at the same total length, which is very unfavorable for optimizing resistance performance.

[0004] While the emerging aft-raked bow significantly reduces wave impact and water resistance at the bow, allowing waves to flow more smoothly over the hull and providing excellent seakeeping performance, its smooth bow, however, offers no resistance to surges. Furthermore, the vertical reserve buoyancy at the bow decreases gradually, resulting in poor pitching resistance and a high risk of the deck catching waves.

[0005] Therefore, it is necessary to design a new bow type to solve the problem that the existing mainstream bow type cannot have both low resistance and high seakeeping performance. Summary of the Invention

[0006] In view of this, the present invention addresses the deficiencies of the existing technology and proposes an Ω-shaped scissor-type bow, aiming to solve the problem that the existing bow form cannot have both low resistance and high seakeeping performance.

[0007] The present invention provides an Ω-shaped scissor-shaped bow, which is characterized in that it comprises: a streamlined lower submerged body (1), a rearward-inclined lower hull (2), and a forward-inclined upper bow column (3); the lower end of the forward-inclined upper bow column (3) and the upper end of the rearward-inclined lower hull (2) intersect at a point (A), and the point (A) is located above a design waterline (4); the forward-inclined upper bow column (3) tilts from the intersection (A) to the upper right at a forward tilt angle α, and the rearward-inclined lower hull (2) tilts from the intersection (A) to the lower right at a rear tilt angle β, and the two form a "<"-shaped bow.

[0008] Furthermore, the cross-section line passing through the intersection (A) has a preset geometric shape, the cross-section line below the intersection (A) is teardrop-shaped, and the cross-section line above the intersection (A) is V-shaped.

[0009] Furthermore, the side profile and top profile of the streamlined lower submerged body (1) along the length of the ship are bionic streamlined structures, and the streamlined lower submerged body (1) and the rearward-inclined lower hull (2) form an Ω-shaped cross-sectional configuration.

[0010] Furthermore, the head end of the streamlined lower submerged body (1) protrudes toward the bow direction from the bottom end point (D) of the rearward-inclined lower hull (2), and the protruding length (L1) is 10% of the longitudinal section chord length (BC) of the streamlined lower submerged body (1).

[0011] Furthermore, the forward endpoint (C) of the streamlined lower submerged body (1) is located below the hull baseline (5), the rear endpoint (B) of the streamlined lower submerged body (1) is located on the hull baseline (5), and the mid-longitudinal section chord length (BC) forms a negative angle θ with the hull baseline (5), and the value of the negative angle θ is K1.

[0012] Furthermore, the distance between the lowest point of the arc of the bottom section line (1b) and the head end point (C) is L2, and the length of L2 is 20%-30% of the length of the longitudinal section chord of the streamlined lower submerged body (1).

[0013] Furthermore, the top section line (1a) and the bottom section line (1b) of the streamlined lower submerged body (1) are symmetrical with respect to the mid-longitudinal section chord length (BC) of the streamlined lower submerged body (1).

[0014] Furthermore, the cross section of the streamlined lower submerged body (1) is an elliptical cross section, and the major axis and the minor axis of the elliptical cross section must satisfy b2≥b1.

[0015] Furthermore, the value of the angle (α) between the rearward-inclined bow column (2a) of the rearward-inclined lower hull (2) and the hull baseline (5) is K2, and the value of the angle (β) between the upper bow column (3) and the hull baseline (5) is K3.

[0016] Furthermore, a fold line (6) is provided between the rearward-inclined lower hull (2) and the side outer plate.

[0017] Compared with existing technologies, the present invention offers the following advantages: Its Ω-shaped scissor-shaped bow structure, formed by a streamlined lower hull, a rearward-inclined lower hull, and a forward-inclined upper stem, not only improves resistance performance but also offers numerous technical advantages, including reduced headwave impact, smoother water flow, reduced vertical heave, reduced pitching, and reduced deck resistance to waves. This provides the dual advantages of both resistance performance and seakeeping.

[0018] The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

[0019] Other features and aspects of the present disclosure will become more apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific 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 any creative work.

[0021] Figure 1 For the existing forward-leaning bow;

[0022] Figure 2 For the existing rear-tilted bow;

[0023] Figure 3 A typical side view of the Ω-shaped scissor-shaped bow of the present invention;

[0024] Figure 4 This is a typical cross-sectional view of the Ω-shaped scissor-shaped bow of the present invention;

[0025] Figure 5 This is a top view of the Ω-shaped scissor-shaped bow submerged body 1 of the present invention;

[0026] Among them: 1-lower body; 1a-lower body top section line; 1b-lower body bottom section line; 1c-lower body top view outline; 2-lower hull; 3-upper stem; 12-cross section line of the part below point A; 23-cross section line of the part above point A; 4-design waterline; 5-hull baseline (5); 6-angle line; Point A-intersection of the upper end of the lower hull and the lower end of the upper stem; Point B-intersection of the lower hull top section line and the lower section line at the tail end; Point C-lower The bow end point of the submerged body; Point D - the intersection of the bottom end of the lower hull and the lower submerged body; JJ - the cross section at point A; θ - the angle between the chord length of the lower submerged body and the hull baseline; α - the angle between the bow column of the lower hull and the bottom baseline; β - the angle between the upper bow column and the bottom baseline; b1 - the short axis of the cross section of the lower submerged body; b2 - the long axis of the cross section of the lower submerged body; L1 - the net protruding length of the bow end of the lower submerged body; L2 - the length of the maximum cross section of the lower submerged body from the bow end; 7 - forward-inclined bow column; 8 - aft-inclined bow column. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, welding connections, or chemical connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0031] See Figure 3-5 As shown, according to an embodiment of the present application, an Ω-shaped scissor-type bow comprises: a streamlined lower submerged body (1), a rearward-inclined lower hull (2), and a forward-inclined upper bow column (3); the lower end of the upper bow column (3) intersects with the upper end of the rearward-inclined lower hull (2) at an intersection (A), and the point (A) is located above the design waterline (4); the forward-inclined upper bow column (3) tilts from the intersection (A) to the upper right at a forward inclination angle α, and the rearward-inclined lower hull (2) tilts from the intersection (A) to the lower right at a backward inclination angle β, and the two form a "<"-shaped bow.

[0032] It is understandable that the special structure formed by the rearward-inclined lower hull and the forward-inclined upper stem makes it difficult for the deck to ride on waves and greatly reduces the degree of wave impact on the bow. In addition, the bionic streamlined lower hull and the rearward-inclined lower hull work together to not only improve the resistance performance, but also significantly reduce the pitch angle and vertical heave amplitude of the ship in waves. The combined effect of the streamlined lower hull (1), the rearward-inclined lower hull (2) and the forward-inclined upper stem (3) greatly improves the ship's seakeeping and resistance performance, and the overall performance is excellent.

[0033] In some specific embodiments, the cross-section line passing through the intersection (A) has a preset geometric shape, the cross-section line below the intersection (A) is teardrop-shaped, and the cross-section line above the intersection (A) is V-shaped.

[0034] It can be understood that the cross-section below the intersection (A) is teardrop-shaped. From the perspective of wave resistance, this shape has a unique effect in wave motion. When the bow moves upward (tilts), since the teardrop-shaped bottom is large and the upper part is small, the teardrop-shaped shape can provide an additional damping in a downward direction to suppress the further upward movement of the bow; conversely, when the bow moves downward (buries the bow), still since the teardrop-shaped bottom is large and the upper part is small, the teardrop-shaped shape will generate an additional buoyancy in an upward direction to suppress the further downward movement of the bow.

[0035] In addition, while the teardrop-shaped shape suppresses the pitching motion of the bow, the water pressure in its cross section is nonlinearly distributed, and each movement has a pressure peak point. This unique pressure distribution means that during the periodic pitching motion of the bow, the teardrop-shaped shape can provide sufficient additional external force without completely blocking the flow of water or completely changing the direction of the water pressure. Therefore, while resisting and delaying the pitching motion of the bow, it will not cause violent slapping or vibration of the bow bottom. Therefore, the comprehensive performance in all aspects of seakeeping far exceeds that of any current mature bow.

[0036] It's understandable that the cross-section above the intersection (A) is V-shaped. As part of improving seakeeping, the V-shaped structure on the side not only has a simple curved surface that facilitates construction, but also forms a natural dihedral angle with the horizontal plane, which is significantly effective in suppressing side splash at high speeds and the amplitude of pitching motion in waves. Specifically, when a ship is sailing at high speeds, the huge pressure difference under the ship's bottom causes a large amount of splash on both sides. The natural dihedral angle formed between the V-shaped structure and the horizontal plane just suppresses the upwelling of the splash, allowing the ejected water to quickly break away from the hull and return to the water, which is very beneficial for reducing resistance during high-speed sailing.

[0037] In addition, the V-shaped broadside structure, while suppressing high-speed splashing, plays an irreplaceable role in suppressing the bow's pitching motion in waves and preventing large waves from hitting the deck. Specifically, as a ship navigates through waves, the bow inevitably experiences pitching motion. Especially when encountering swells, due to the large pitching amplitude of the bow and the high wave height, it is easy for the bow to sink into the water, causing large waves to hit the bow deck, seriously threatening the safety of the ship and preventing normal navigation. The V-shaped broadside structure can effectively solve this problem. Since the pressure distribution of the V-shaped cross-section increases exponentially from bottom to top, it has a great resistance to the bow's pitching motion and waves. The moment the swell hits the bow from the front, it can generate a huge reserve buoyancy. At the same time, the V-shaped structure allows water to flow diagonally upward and then outboard, effectively avoiding the hidden danger of large waves hitting the deck, further improving the ship's wavekeeping performance and ensuring the ship's safe navigation in waves.

[0038] In some specific embodiments, the lower hull (2) has a rearward-inclined bow. This design is beneficial to both seakeeping and resistance. Specifically, when a surge hits the bow from the front, firstly, due to the rearward-inclined bow, the wave will hit the bow at a smaller angle of attack, which is beneficial to resistance; secondly, because the pressure of the rearward-inclined bow decreases gradually from bottom to top, when encountering a surge, the water flow can flow smoothly through the hull without causing obvious obstruction or bow slapping, which is beneficial to seakeeping.

[0039] In some specific embodiments, the side profile and top profile of the streamlined lower hull (1) along the length of the ship are both bionic streamlined structures, and the streamlined lower hull (1) and the rearward-inclined lower hull (2) form an Ω-shaped cross-sectional configuration, which has the dual functions of "rectification and drag reduction" and "heave suppression". Specifically, when the ship is sailing forward at high speed, since the hull water flow at high speed is a turbulent field, the Ω-shaped cross-sectional configuration formed by the streamlined lower hull (1) and the rearward-inclined lower hull (2) can play a "rectification" role, making the flow field at the bow more regular, thereby reducing resistance. In addition, the streamlined lower hull (1) also protrudes a certain length toward the bow, which can generate an additional interference wave system, forming a phase difference with the main waveform of the main hull, thereby offsetting part of the wave energy, and further playing a role in reducing resistance.

[0040] Furthermore, when the ship performs a pitching motion, the Ω-shaped cross-sectional configuration formed by the streamlined lower submerged body (1) and the rearward-inclined lower hull (2) can provide an additional external force in the opposite direction of the bow movement, thereby suppressing the bow heave and resisting the pitching motion, thereby improving the seakeeping performance in waves.

[0041] It can be understood that the present application forms an Ω-shaped cross-sectional configuration through the streamlined lower submerged body (1) and the rearward-inclined lower hull (2), and the synergistic effect of the V-shaped side structure above, so that the bow has low resistance, high wave resistance, and strong anti-pitch roll capability, which is particularly suitable for ship navigation in complex sea conditions and significantly improves the comprehensive performance and environmental adaptability of the ship.

[0042] In some specific embodiments, the head end of the streamlined lower submerged body (1) protrudes toward the bow direction compared to the bottom end point (D) of the rearward-inclined lower hull (2), and the protruding length (L1) is 10% of the longitudinal section chord length (BC) of the streamlined lower submerged body (1).

[0043] It is understandable that the design of a streamlined lower hull with a forward protruding bow and a length L1 that is 10% of the chord length of the mid-longitudinal section can, firstly, extend the effective length of the ship below the waterline without increasing the ship's length as defined by the regulations, optimize the line parameters to reduce wave-making resistance; secondly, the forward-extending bow of the lower hull can be the first to cut into the waves, using the bionic streamlined contour to guide the water flow smoothly along the rearward-inclined lower hull, reducing the impact of waves on the bow and suppressing pitching motion; thirdly, it can generate an additional interference wave system that superimposes with the main waveform of the main hull, thereby playing a role in wave and drag reduction. Therefore, this protruding length has been hydrodynamically optimized to avoid structural redundancy while improving the overall navigation performance of the ship, forming a synergistic relationship with the rearward-inclined lower hull and the forward-inclined upper stem, taking into account both resistance performance and seakeeping.

[0044] 11. In some specific embodiments, the distance between the lowest point of the arc of the bottom section line (1b) and the head end point (C) is L2, and the length of L2 is 20% to 30% of the length of the longitudinal section chord of the streamlined lower submerged body (1).

[0045] It can be understood that the streamlined lower submerged body (1) adopts a bionic design, the inflow length accounts for 20% to 30% of the total length of the streamlined lower submerged body (1), and the outflow length accounts for 70% to 80% of the total length of the streamlined lower submerged body (1). Such a proportional design is very consistent with the ideal fluid motion characteristics, has the minimum self-resistance and the maximum motion benefit, and can maximize the improvement of resistance performance and wave resistance performance.

[0046] In some specific embodiments, the forward endpoint (C) of the streamlined lower body (1) is located below the hull baseline (5), and the rear endpoint (B) of the streamlined lower body (1) is located on the hull baseline (5); the top section line (1a) and the bottom section line (1b) of the streamlined lower body (1) are symmetrical about the mid-longitudinal section chord length (BC) of the streamlined lower body (1), and the mid-longitudinal section chord length (BC) forms a negative angle θ with the hull baseline (5), and the value of the negative angle θ is K1.

[0047] Specifically, the K1 is -1°--2°.

[0048] It can be understood that the design of the streamlined lower submerged body with the top and bottom sections symmetrical about the chord length of the mid-longitudinal section can make the water flow evenly attached and separated on the upper and lower surfaces, reduce the resistance and heeling moment caused by the asymmetry of the flow field, and improve the navigation stability; the chord length of the mid-longitudinal section forms a negative angle of -1° to -2° with the hull baseline, so that the lower submerged body as a whole is slightly tilted downward. Such a design is just the same as the longitudinal tilt angle of the ship when it is sailing at high speed, and the direction is opposite. This means that when the bow is raised, the streamlined lower submerged body (1) can just move forward at the optimal angle, which plays an important role in maintaining the ship's motion posture and reducing wave-making resistance.

[0049] In some specific embodiments, the cross section of the streamlined lower submerged body (1) is an elliptical cross section, and the major axis and the minor axis of the elliptical cross section must satisfy b2≥b1.

[0050] It can be understood that the purpose of keeping the major axis b2 of the elliptical cross-section always greater than or equal to the minor axis b1 is to increase the aspect ratio of the teardrop-shaped cross-section, making it wider in the ship width direction and narrower in the ship depth direction. Such a shape can increase the additional vertical damping, which is of great significance for suppressing vertical heave movement and improving seakeeping.

[0051] In some specific embodiments, the value of the angle (α) between the rearward-inclined lower hull (2) and the hull baseline (5) is K2, and the value of the angle (β) between the upper stem (3) and the hull baseline (5) is K3.

[0052] Specifically, the K2 is 120°-150°; the K3 is 30°-45°

[0053] It can be understood that the bow of the aft-inclined lower hull forms an obtuse angle (α) of 120° to 150° with the hull baseline, creating a backward-inclined guide surface on the lower hull. This effectively guides the incoming wave flow to pass smoothly along the sides of the hull, reducing the obstruction and impact of the water flow at the bow, reducing wave resistance and improving seakeeping performance. The upper bow is tilted forward at an acute angle (β) of 30° to 45° with the hull baseline, providing sufficient reserve buoyancy during the bow pitching movement and blocking waves from surging onto the deck through the forward tilt angle, reducing the risk of wave-breaking. The combination of the two angles forms a scissor-shaped composite structure with "upper wave protection and lower flow rectification." This structure combines the advantages of the aft-inclined bow's smooth water flow while retaining the wave-resistance characteristics of the forward-inclined bow. Through the coordinated action of the different tilt angles of the upper and lower hulls and the combined effect of the streamlined lower submerged body, the ship's pitching amplitude is significantly reduced, vertical heave is reduced, and both resistance performance and seakeeping performance are optimized, making it suitable for high-speed navigation in complex sea conditions.

[0054] In some specific embodiments, a fold line (6) is provided between the rearward-inclined lower hull (2) and the side outer plate.

[0055] It can be understood that the angle line (6) is set between the rearward-inclined lower hull and the side outer plate, which can optimize the separation and attachment characteristics of water flow in the bow area through the sudden change of the geometric profile. With the angle line (6) as the boundary, on the one hand, a water drop-shaped structure is formed at the lower part, which guides the side water flow to flow smoothly below the angle line, reduces the water flow impact and vortex caused by the blunt and steep curved surface, and reduces the wave resistance and shape resistance; on the other hand, a V-shaped side structure is formed at the upper part, which has a significant effect on blocking side splashing and improving the reserve buoyancy.

[0056] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An Ω-shaped scissor bow, characterized in that: include: A streamlined lower submerged body (1), a rearward-inclined lower hull (2), and a forward-inclined upper bow column (3); the lower end of the upper bow column (3) intersects with the upper end of the rearward-inclined lower hull (2) at an intersection point (A), and the point (A) is located above a designed waterline (4); the upper bow column (3) tilts from the intersection point (A) to the upper right at a forward-inclined angle α, and the bow column (2a) tilts from the intersection point (A) to the lower right at a backward-inclined angle β, and the two form a "<"-shaped bow.

2. A scissor-shaped bow according to claim 1, characterized in that: The cross-section line passing through the intersection (A) has a preset geometric shape. The cross-section line below the intersection (A) is teardrop-shaped, and the cross-section line above the intersection (A) is V-shaped.

3. The scissor-shaped bow according to claim 1, characterized in that: The side profile and top profile of the streamlined lower submerged body (1) along the length of the ship are bionic streamlined structures, and the streamlined lower submerged body (1) and the rearward-inclined lower hull (2) form an Ω-shaped cross-sectional configuration.

4. The scissor-shaped bow according to claim 1, characterized in that: The head end of the streamlined lower submerged body (1) protrudes toward the bow direction compared to the bottom end point (D) of the rearward-inclined lower hull (2), and the protruding length (L1) is 10% of the longitudinal section chord length (BC) of the streamlined lower submerged body (1).

5. The scissor-shaped bow according to claim 1, characterized in that: The forward end point (C) of the streamlined lower submerged body (1) is located below the hull baseline (5), the rear end point (B) of the streamlined lower submerged body (1) is located on the hull baseline (5), and the mid-longitudinal section chord length (BC) forms a negative angle θ with the hull baseline (5), and the value of the negative angle θ is K1.

6. The scissor-shaped bow according to claim 1, characterized in that: The distance between the arc-shaped lowest point of the bottom section line (1b) and the head end point (C) is L2, and the length of L2 is 20% to 30% of the length of the longitudinal section chord of the streamlined lower submerged body (1).

7. The scissor-shaped bow according to claim 1, characterized in that: The top section line (1a) and the bottom section line (1b) of the streamlined lower submerged body (1) are symmetrical with respect to the mid-longitudinal section chord length (BC) of the streamlined lower submerged body (1).

8. The scissor-shaped bow according to claim 1, characterized in that: The cross section of the streamlined lower submerged body (1) is an elliptical cross section, and the major axis length b2 and the minor axis length b1 of the elliptical cross section must satisfy b2≥b1.

9. The scissor-shaped bow according to claim 1, characterized in that: The value of the angle (α) between the rearward-inclined lower hull (2) and the hull baseline (5) is K2, and the value of the angle (β) between the upper stem (3) and the hull baseline (5) is K3.

10. The scissor-shaped bow according to claim 1, characterized in that: A fold line (6) is provided between the rearward-inclined lower hull (2) and the side outer plate.

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