M-shaped bubble drag reduction channel stepped planing boat and drag reduction method

Abstract

The invention discloses an M-shaped bubble drag reduction channel stepped planing boat and a drag reduction method, and mainly relates to the technical field of ship air drag reduction. Comprising a ship body and an auxiliary body, the ship body comprises an M-shaped channel planing boat or is formed by combining a plurality of M-shaped channel planing boats in parallel, an air channel is formed in the bottom of each M-shaped channel planing boat, and vertical rigid side skirts are arranged on the left side and the right side of the bottom of the ship body. An air leading-in opening is formed in the position, above the waterline, in an air channel at the bow of the M-shaped channel planing boat, a hydrofoil is arranged below a step, air leading-out holes are formed in the bottom of the step and / or the upper surface of the hydrofoil, and the air leading-out holes are communicated with the air leading-in opening through a pipeline. An air generating device is not adopted, energy consumption is reduced, a larger microbubble layer covering the tail of the ship can be formed, the microbubble layer and air in the channel form an air layer integrally surrounding the bottom of the ship, and frictional resistance, viscous pressure resistance and wave-making resistance of the ship are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ship air drag reduction, in particular to an M-type bubble drag reduction channel step-down planing boat and a drag reduction method. Background Art

[0002] When a ship is sailing, it will generate various resistances. For example, due to the viscosity of seawater, a boundary layer is formed between the hull and the seawater, which generates a velocity gradient and forms friction resistance. At the same time, due to the viscosity of seawater, a pressure difference is generated between the head and tail of the ship's wet area, forming viscous pressure resistance. In addition, waves are generated during navigation, forming wave-making resistance. In order to overcome resistance and gain speed during navigation, a ship needs a greater ship propulsion power, which increases energy consumption and produces carbon dioxide. With the development of the shipping industry, air drag reduction technology uses gas to form an air layer on the bottom of the ship, which can reduce the ship's wet area and fluid viscosity, thereby reducing ship resistance and main engine power consumption, and improving fuel efficiency and environmental performance.

[0003] However, the existing air drag reduction technology mainly uses an air generating device to generate gas and inject the gas into the bottom of the ship. For example, the invention patent named: A bubble drag reduction channel planing boat (publication number: CN109808827A) reduces the resistance of the ship, but requires an additional micro-bubble generator, which still generates a lot of energy consumption; the utility model patent named: A high-speed planing boat air injection air cushion structure (publication number: CN221316551U) installs an airflow pipe and a guide cover on the top of the hull to introduce air into the bottom of the ship, and two bubble spreading grooves are symmetrically arranged at the tail of the hull. However, on the one hand, the patent only distributes bubbles at the bubble spreading groove on the bottom of the ship, and can only generate a bubble layer locally on the bottom of the ship, and cannot form an overall surrounding bubble layer and air layer, and the drag reduction rate is relatively low; on the other hand, it is difficult to ensure that the gas collected on the top of the hull enters the bubble integration groove on the bottom of the ship. In addition, the above schemes cannot avoid the problem of air escape. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to provide an M-type bubble drag reduction channel step-down planing boat and a drag reduction method. The air generating device is not used, so the energy consumption is reduced, and a larger micro-bubble layer covering the bottom of the boat can be formed, forming an air layer that surrounds the bottom of the boat as a whole, thereby greatly reducing the navigation resistance of the boat.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] An M-type bubble drag reduction slot step planing boat comprises a hull, wherein the hull comprises an M-type slot planing boat or is composed of a plurality of M-type slot planing boats arranged in parallel, an air slot is provided at the bottom of the M-type slot planing boat, the length direction of the air slot is consistent with the length direction of the M-type slot planing boat, vertical rigid side skirts are provided at both left and right ends of the bottom of the hull, a step is provided at the bottom of the M-type slot planing boat, an air inlet is provided at a position above the waterline in the air slot at the bow of the M-type slot planing boat, a hydrofoil is provided below the step, an air outlet hole is provided at the bottom of the step and / or at the upper surface of the hydrofoil, and the air outlet hole is connected to the air inlet through a pipeline.

[0007] Preferably, the hull is composed of two M-type channel planing boats combined in parallel.

[0008] Preferably, the step is arranged at the rear third to the rear quarter of the M-type channel planing boat.

[0009] Preferably, the inner diameter of the air inlet is larger than the inner diameter of the air outlet hole, and the inner diameter of the air outlet hole is less than 3 mm.

[0010] Preferably, a one-way valve is provided in the pipeline.

[0011] A drag reduction method for an M-type bubble drag reduction channel step-type planing boat. When the hull is gliding, the bottom of the stern of the hull is below the water surface, and the negative pressure generated by the steps and hydrofoils on the bottom of the hull naturally sucks the squeezed air in the air channel into the bottom of the hull, forming microbubbles near the air outlet holes; the microbubble layer can be tightly adsorbed on the bottom of the hull under the action of the steps and hydrofoils, and flows toward the stern of the hull along the water flow under the action of the hydrofoils, and at the same time diffuses to both sides of the hull and merges with the air in the air channel; the vertical rigid side skirts on both sides block the diffusion path of the air to both sides of the hull, so that the air layer moves toward the stern as a whole, and forms an overall air and bubble coating layer on the bottom of the hull, thereby greatly reducing the navigation resistance of the ship.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The present invention utilizes the pressure difference between the high-pressure area at the air inlet and the negative-pressure area at the step when the ship is sailing, so as to naturally suck the air in the air channel into the pipe in the hull and form a micro-bubble layer at the air outlet hole; vertical rigid side skirts are arranged on both sides of the hull to prevent the air in the air channel from diffusing outwards, thereby reducing wave-making resistance; when sailing, the air at the bow is squeezed into the air channel, and the air layer moves along the air channel to the stern to form an air layer, and the air cushion lifts the hull to reduce resistance; the hydrofoil is below the step, and the dynamic lift formed by the hydrofoil makes the micro-bubbles fit the bottom of the ship, and the fast water flow above the hydrofoil guides the bubble layer to diffuse to the stern; the present invention has a simple structure, does not generate energy consumption, and saves energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention;

[0015] Figure 2 is a bottom view of the present invention;

[0016] Figure 3 is a side view of the present invention;

[0017] Figure 4 is a cross-sectional view of a fault of the present invention;

[0018] Figure 5 It is a partial enlarged view of the fault level of the present invention.

[0019] Numbers in the attached drawings: 1. hull; 2. air channel; 3. vertical rigid side skirt; 4. step; 5. air inlet; 6. hydrofoil; 7. air outlet hole; 8. one-way valve; 9. pipeline. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

[0021] Embodiment 1: As attached Figure 1-5 As shown, the present invention is an M-type bubble drag reduction channel step-down planing boat, including a hull 1, wherein the hull 1 includes an M-type channel planing boat or is composed of a plurality of M-type channel planing boats arranged in parallel. The hull 1 in this embodiment is composed of two M-type channel planing boats arranged in parallel.

[0022] An air channel 2 is provided at the bottom of the M-type channel planing boat, and the length direction of the air channel 2 is parallel to the length direction of the M-type channel planing boat. A double M-type ship with four air channels 2 is adopted. The four air channels 2 can capture a large amount of air, so that the ship can enter the planing state at a lower speed.

[0023] Vertical rigid side skirts 3 are provided at the left and right ends of the bottom of the hull 1, forming a ship structure consisting of a four-channel double-V-shaped main hull and vertical rigid side skirts on both sides. This ship structure can capture more air, and the rigid vertical side skirts 3 can prevent the air in the channel from escaping, reduce wave-making resistance, and enable the hull to quickly transition from a displacement state to a gliding state, thereby improving the speed of the ship.

[0024] The bottom of the M-type channel planing boat is provided with steps 4. When sailing, the air channel 2 on the bottom of the boat introduces the air from the bow into the channel to form an air layer to lift the front part of the bottom of the boat out of the water. The steps 4 can be set at one-third and one-quarter of the bottom of the boat near the tail, reducing the wet area of ​​the underwater part of the bottom of the boat, thereby reducing the friction resistance.

[0025] An air inlet 5 is provided above the waterline in the air channel 2 at the bow of the M-type channel planing boat, a hydrofoil 6 is provided below the step 4, an air outlet hole 7 is provided at the bottom of the step 4 and / or the upper surface of the hydrofoil 6, and the air outlet hole 7 is connected to the air inlet 5 through a pipe 9, so that the air in the air channel 2 is introduced into the step 4 to form microbubbles.

[0026] Preferably, the curvature of the upper surface of the hydrofoil 6 is greater than that of the lower surface.

[0027] When the ship is gliding, at the stern of the hull 1, about 1 / 4 of the length of the bottom of the ship is still below the water surface, generating friction resistance and viscous pressure resistance. The existence of the air outlet hole 7, the air inlet 5, and the pipe 9 allows the air to be sucked into the pipe 9 under the negative pressure at the stern step 4, forming microbubbles near the air outlet hole 7. The microbubbles diffuse to both sides along the hull 1 in the horizontal direction and merge into the air channels 2 on both sides. In the longitudinal direction, they diffuse toward the stern under the action of the water flow. The dynamic lift generated by the hydrofoil 6 can play a role in reducing resistance. At the same time, negative pressure is formed above the hydrofoil 6, making the bubbles more adhered to the bottom of the ship. Under the action of the high-speed water flow, they move to the stern to form a microbubble layer at the bottom of the ship. The air layer in the air channel 2 is connected to the microbubble layer after the step 4. Under the obstruction of the vertical rigid side skirts 3 on both sides, an air layer surrounding the bottom of the ship is formed, producing an effect similar to "supercavitation", thereby greatly reducing the navigation resistance of the ship and saving energy consumption.

[0028] The present invention utilizes the negative pressure generated by the steps 4 and the hydrofoils 6 of the bottom of the ship to naturally suck the squeezed air in the air channel 2 into the bottom of the ship, thereby reducing the energy consumption of the air generating device and increasing the amount of air collected and the speed at the bubble outlet; the microbubble layer can be tightly adsorbed on the bottom of the ship under the action of the steps 4 and the hydrofoils 6, and flows toward the stern of the ship along the water flow under the action of the hydrofoils 6, and at the same time diffuses to both sides of the hull 1 and merges with the air in the air channel 2, and the vertical rigid side skirts 3 on both sides block the path of air diffusion to both sides of the hull 1, so that the air layer moves toward the stern as a whole, forming an overall air and bubble coating layer on the bottom of the ship.

[0029] Preferably, the inner diameter of the air inlet 5 is larger than the inner diameter of the air outlet hole 7, and the inner diameter of the air outlet hole 7 is less than 3 mm.

[0030] Preferably, a one-way valve 8 is provided in the pipeline 9, and the one-way flow of air is maintained through the one-way valve 8.

[0031] The present invention utilizes the positive pressure of the bow and the negative pressure generated at the step 4 when the ship is sailing, so as to naturally inhale the air in the air channel 2 into the pipe 9 in the hull 1, and form a microbubble layer near the air outlet 7. No power generating device is used, so energy consumption is reduced and it is more environmentally friendly. The present invention installs a hydrofoil 6 at the step 4, and utilizes the dynamic lift generated by the hydrofoil 6 to make the microbubbles tightly adsorbed on the bottom of the ship, so as to reduce the bubble escape. The high-speed water flow generated by the hydrofoil 6 guides the microbubble layer to diffuse toward the stern, so as to form a larger microbubble layer covering the stern. The present invention adopts an M-type air channel step planing boat, and the air layer in the air channel is connected with the microbubble layer generated at the step, so as to form an overall package. The air layer surrounding the bottom of the ship greatly reduces the friction resistance and viscous pressure resistance of the ship; the present invention adopts an M-type air channel stepped planing boat, and the rigid vertical side skirts 3 reduce the wave-making resistance, block the air from overflowing to both sides, and form a closed vacancy layer on the bottom of the ship; the air outlet hole 7 of the present invention is installed at the vertical step 4, which is conducive to the generation of microbubbles. The air outlet hole 7 is not limited to being set at the step 4, and can also be set on the upper surface of the hydrofoil 6 at the step 4. The negative pressure at the step 4 and the dynamic lift of the hydrofoil 6 can also push the microbubbles to the bottom of the ship. The formed microbubble layer can also be diffused to the stern under the action of the high-speed water flow above the hydrofoil 6 and in the middle of the bottom of the ship, forming a larger microbubble layer.

[0032] Embodiment 2: The present invention discloses a drag reduction method for an M-type bubble drag reduction channel step-down planing boat. When the hull 1 is planing, the bottom of the stern of the hull 1 is below the water surface. The negative pressure generated by the step 4 and the hydrofoil 6 of the bottom of the hull naturally sucks the squeezed air in the air channel 2 into the bottom of the hull, and forms microbubbles near the air outlet 7. The microbubble layer can be tightly adsorbed on the bottom of the hull under the action of the step 4 and the hydrofoil 6, and flows along the water flow to the stern of the hull 1 under the action of the hydrofoil 6, and at the same time diffuses to both sides of the hull 1 and merges with the air in the air channel 2. The vertical rigid side skirts 3 on both sides block the path of air diffusion to both sides of the hull 1, so that the air layer moves toward the stern as a whole, and forms an overall air and bubble coating layer on the bottom of the hull, thereby greatly reducing the navigation resistance of the ship. The present invention can actively capture the air in the air channel, use the negative pressure of the bottom of the hull to suck the air into the bottom of the hull, and realize that the wet area of ​​the bottom of the hull is almost completely covered by the air layer and the bubble layer when the gliding state is achieved.

Claims

1. An M-type bubble drag reduction channel step-down planing boat, comprising a hull (1), characterized in that: The hull (1) comprises an M-type slot planing boat or is composed of a plurality of M-type slot planing boats arranged in parallel. An air slot (2) is provided at the bottom of the M-type slot planing boat. The length direction of the air slot (2) is consistent with the length direction of the M-type slot planing boat. Vertical rigid side skirts (3) are provided on both sides of the hull (1). A step (4) is provided at the bottom of the M-type slot planing boat. An air inlet (5) is provided above the waterline in the air slot (2) at the bow of the M-type slot planing boat. A hydrofoil (6) is provided below the step (4). An air outlet hole (7) is provided at the bottom step of the step (4) and / or at the upper surface of the hydrofoil (6). The air outlet hole (7) is connected to the air inlet (5) via a pipe (9).

2. The M-type bubble drag reduction channel step-down planing boat according to claim 1, characterized in that: The hull (1) is composed of two M-shaped channel planing boats arranged in parallel.

3. The M-type bubble drag reduction channel step-down planing boat according to claim 1, characterized in that: The step (4) is arranged at the rear third to the rear quarter of the M-shaped channel planing boat.

4. The M-type bubble drag reduction channel step-down planing boat according to claim 1, characterized in that: The inner diameter of the air inlet (5) is larger than the inner diameter of the air outlet hole (7), and the inner diameter of the air outlet hole (7) is less than 3 mm.

5. The M-type bubble drag reduction channel step-down planing boat according to claim 1, characterized in that: A one-way valve (8) is arranged in the pipeline (9).

6. A drag reduction method for an M-type bubble drag reduction channel step-down planing boat as claimed in any one of claims 1 to 5, characterized in that: When the hull (1) is gliding, the bottom of the stern of the hull (1) is below the water surface, and the negative pressure generated by the steps (4) and the hydrofoils (6) on the bottom of the hull naturally sucks the squeezed air in the air channel (2) into the bottom of the hull, forming microbubbles near the air outlet holes (7); the microbubble layer can be tightly adsorbed on the bottom of the hull under the action of the steps (4) and the hydrofoils (6), and flows along the water flow to the stern of the hull (1) under the action of the hydrofoils (6), and at the same time diffuses to both sides of the hull (1) and merges with the air in the air channel (2), and the vertical rigid side skirts (3) on both sides block the diffusion path of the air to both sides of the hull (1), so that the air layer moves toward the stern as a whole, forming an overall air and bubble coating layer on the bottom of the hull, thereby greatly reducing the navigation resistance of the ship.

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