Bubble generating device for air lubrication and resistance reduction ship
By designing bubble generating devices for the main gas chamber, side gas chambers, and exhaust chamber, the problems of uneven gas distribution and bifurcation/breakage were solved, achieving uniform gas layer distribution and increasing coverage area, thus improving drag reduction effect.
Patent Information
- Application Number
- CN202520132854.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2035-01-21
AI Technical Summary
In the prior art, the gas distribution in the gas passage of the bottom bubble generator is uneven, which makes it easy for the gas to split and break, thus affecting the drag reduction effect.
Design a bubble generating device, including a main air chamber, a side air chamber and an exhaust chamber. The main air chamber and the side air chamber are connected by an internal connecting hole. The exhaust chamber is in contact with water flow. The bubbles coming out of the side air vents serve as a supplement to the upper air vent, forming a stable gas layer and preventing branching and breakage.
It achieves uniform distribution of the gas layer, increases the gas layer coverage area, and enhances the drag reduction effect.
Smart Images
Figure CN223644925U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of ship drag reduction technology, specifically relating to a bubble generating device for air-lubricated drag-reducing ships. Background Technology
[0002] Marine air lubrication drag reduction technology refers to a flow control method that introduces gas into the near-wall boundary layer of the liquid phase, utilizing the "lubricating" effect of the gas to reduce the drag at the bottom of the ship. Introducing a continuous and stable gas into the hull can achieve better drag reduction results, but this requires a corresponding bubble generator. Therefore, various bubble generators have emerged in the industry. Some bubble generators are integrated with the hull, with their bottom surface conforming to the hull plane, and have a single vent. However, the gas layer from a single vent in these hull-bottom bubble generators is not continuous enough, and localized gas layer breakage can occur, significantly reducing the drag reduction effect. Furthermore, due to surface tension, the continuous gas layer from a single vent is often thicker in the middle and thinner at the sides, making it prone to bifurcation and breakage under buoyancy, further affecting the drag reduction effect.
[0003] Therefore, there is an urgent need to design a bubble generator for air-lubricated, drag-reducing ships, to avoid the problems of discontinuous gas layers and easy branching and breakage that occur in traditional bubble generators with only a single vent. Utility Model Content
[0004] The purpose of this invention is to overcome the problem that the air layer produced by the existing bottom bubble generator is thin and not uniform enough, and to provide a bubble generator for air-lubricated and drag-reducing ships.
[0005] The specific technical solution adopted in this utility model is as follows:
[0006] This utility model provides a bubble generating device for air-lubricated and drag-reducing ships, including a main air chamber, a side air chamber and an exhaust chamber disposed on the bottom plate;
[0007] The main air chamber is located on the bottom plate connected to the outer hull plate. The top is connected to the external air supply equipment through an air inlet. Side air chambers are symmetrically arranged on the left and right sides. The main air chamber and the side air chambers are connected through an internal connecting hole. The exhaust chamber is an open cavity located below the main air chamber, which can be in direct contact with the water flow. The head end of the exhaust chamber is connected to the main air chamber through an upper air vent, and the two sides are connected to the two side air chambers through side air vents respectively. The bottom of the head end of the exhaust chamber is provided with an air storage cover plate, which is used to guide the gas flowing out of the upper air vent to flow towards the rear of the ship.
[0008] Preferably, the bottom surface of the bottom plate is conformal to the bottom surface of the hull.
[0009] Preferably, two side plates are symmetrically installed on the upper surface of the base plate, with their head ends joined together and their tail ends separated. A top plate and an exhaust chamber top wall are provided between the two side plates near the head ends. The top plate is located above the exhaust chamber top wall and there is a gap between them. A rear side wall is provided behind the top plate and the exhaust chamber top wall. The tail side of the exhaust chamber top wall is smoothly connected to the base plate through an inclined exhaust chamber rear wall. A cover plate is fixed to the outer side of each side plate. The cover plate and the connected side plate form a closed area and serve as a side air chamber. The two side plates, the top plate, the exhaust chamber top wall, and the rear side wall together form the main air chamber. The two side plates, the exhaust chamber top wall, the exhaust chamber rear wall, and the air storage cover plate together form a semi-closed exhaust chamber.
[0010] Furthermore, the side plate is perpendicular to both the bottom plate and the top plate.
[0011] Furthermore, an air inlet is provided on the top plate, an internal connecting hole and a side vent are provided on the side plate, and an upper vent is provided on the top wall of the exhaust chamber.
[0012] Furthermore, the air storage cover is located on the bottom surface of the joint at the head end of the two side plates, and its vertical projection can cover all the upper vents.
[0013] Preferably, the air inlet is a circular hole, the internal connecting hole is a horizontal elongated hole, the side air vent is an elongated hole that slopes backward, and the upper air vent is a horizontal elongated hole that opens laterally.
[0014] Preferably, the upper vent is provided in multiple locations along the length of the hull.
[0015] Preferably, the bottom plate is made of marine steel plate, with a front lifting port at the head end and a rear lifting hole coaxially provided at the end.
[0016] Preferably, the exhaust chamber has a two-section structure, with both the front and rear sections tilted backward, and the tilt angle of the rear section being greater than that of the front section; the height of the exhaust chamber is the optimal turbulence height of the boundary layer.
[0017] Compared with the prior art, this utility model has the following advantages:
[0018] This utility model's ventilation generating device has a side air chamber. After ventilation, the main air chamber outputs a continuous air layer from the upper air port. The side air chamber can uniformly generate stable bubbles, which supplement the continuous air layer output from the upper air port, making the air layer more uniform. At the same time, the bubbles output from the side air port can avoid the bifurcation and breakage phenomenon that occurs when only a single air port is ventilating, thereby increasing the coverage area of the air layer and enhancing the drag reduction effect. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of the device of this utility model;
[0020] Figure 2 for Figure 1 A partial cross-sectional structural diagram;
[0021] Figure 3 This is an isometric view of the bottom surface of the device of this utility model;
[0022] Figure 4 for Figure 3 A structural diagram from the left-hand perspective;
[0023] The attached diagram is labeled as follows: 1 base plate, 11 main air chamber, 12 side air chamber, 13 exhaust chamber, 101 upper vent, 102 side vent, 103 air storage cover, 104 internal connecting hole, 105 front lifting port, 106 rear lifting hole, 107 air inlet, 108 rear wall of exhaust chamber, 109 top wall of exhaust chamber. Detailed Implementation
[0024] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.
[0025] This utility model relates to a ship drag reduction technology based on air lubrication. The main technical idea of air lubrication drag reduction technology is to introduce air into the bottom surface of the ship. Through continuous or discrete bubbles formed between the hull and the water, the density and viscosity of the fluid around the hull are reduced, thereby significantly reducing the frictional resistance of the ship. Specifically, this utility model relates to a bubble generating device that can introduce gas into the bottom of the ship. The device has two sets of air inlets: an upper air inlet and a side air inlet. The upper air inlet can introduce a stable and continuous air layer into the bottom of the ship, while the bubbles coming out of the side air inlets serve as supplementary bubbles to the continuous air layer, increasing the bubble coverage and making the air layer more stable and uniform.
[0026] like Figures 1-4 As shown, this utility model provides a bubble generating device for air lubrication and drag reduction of ships. The bubble generating device mainly includes a main air chamber 11, a side air chamber 12 and an exhaust chamber 13, all of which are disposed on the bottom plate 1.
[0027] In a preferred embodiment of this utility model, the bottom plate 1 is conformal to the outer surface of the hull.
[0028] The structure and connection relationships of each chamber will be explained in detail below.
[0029] In this utility model, such as Figure 1 As shown, the main air chamber 11 is located on the upper surface of the base plate 1, and an air inlet 107 is provided at the top. The main air chamber 11 is connected to an external air supply device through the air inlet 107. Figure 2As shown, side air chambers 12 are symmetrically arranged on the left and right sides of the main air chamber 11, and the main air chamber 11 and the side air chambers 12 are connected by an internal connecting hole 104. The side air chambers 12 do not have separate air inlets, and share the air source with the main air chamber 11 through the internal connecting hole 104.
[0030] In this utility model, such as Figure 3 and 4 As shown, the exhaust chamber 13 is an open cavity located below the main air chamber 11, allowing it to directly contact the water flow during use. The front end of the exhaust chamber 13 is connected to the main air chamber 11 via an upper vent 101, and both sides are connected to two side air chambers 12 via side vents 102. In other words, the exhaust chamber 13 achieves three-sided exhaust through the upper vent 101 and the side vents 102. A gas storage cover 103 is provided at the bottom of the front end of the exhaust chamber 13. The gas storage cover 103 guides the gas flowing from the upper vent 101 towards the rear of the ship, reducing the tendency of the gas to move away from the hull.
[0031] In a preferred embodiment of this utility model, two side plates are symmetrically mounted on the upper surface of the base plate 1. Both side plates are arc-shaped, with their heads facing each other and their tails far apart. A top plate and an exhaust chamber top wall 109 are provided between the two side plates near their heads. The top plate is located above the exhaust chamber top wall 109 and there is a certain gap between them. A vertical rear side wall is provided behind the top plate and the exhaust chamber top wall 109. The tail side of the exhaust chamber top wall 109 is smoothly connected to the base plate 1 through an inclined exhaust chamber rear wall 108. A cover plate is fixed to the outer side of each side plate. The cover plate and the connected side plate form a closed area and serve as a side air chamber 12. The two side plates, the top plate, the exhaust chamber top wall 109, and the rear side wall together constitute the main air chamber 11. The two side plates, the exhaust chamber top wall 109, the exhaust chamber rear wall 108, and the air storage cover plate 103 together constitute a semi-closed exhaust chamber 13.
[0032] Specifically, the side plates, bottom plate 1, and top plate are all vertically arranged. In a more optimal operating environment, both side plates and the rear side wall are vertically arranged, while the bottom plate 1 and top plate are horizontally arranged. Furthermore, the exhaust chamber 13 is divided into two sections by the exhaust chamber top wall 109 and exhaust chamber rear wall 108. Both the front section (i.e., exhaust chamber top wall 109) and the rear section (i.e., exhaust chamber rear wall 108) are inclined rearward, with the rear section's inclination angle greater than the front section's. This arrangement facilitates drainage of water in the air chamber from the main vent along the inclined exhaust chamber top wall when the device is not ventilated (primarily for maintenance). An air inlet 107 is provided on the top plate, an internal connecting hole 104 and a side vent 102 are provided on the side plates, and an upper vent 101 is provided on the exhaust chamber top wall 109. An air accumulator cover 103 is located on the bottom surface of the joint between the two side plates. Its vertical projection covers all the upper vents 101, reducing the tendency of gas to move away from the hull. This allows the gas discharged from the upper vents 101 to be stabilized in the front section of the exhaust chamber 13 (i.e., the exhaust chamber top wall 109), forming a gas layer of sufficient thickness. The rear section of the exhaust chamber 13 (i.e., the exhaust chamber rear wall 108) smoothly connects to the front section (i.e., the exhaust chamber top wall 109) and the bottom plate, allowing the discharged gas to flow close to the upper surface of the ship, thus reducing drag. The height of the exhaust chamber 13 is the optimal turbulence height for the boundary layer, and the length of the exhaust chamber 13 allows the gas layer to develop fully and reduces its fluctuations and instability. Gas from the side air chamber 12 exits through the side vent 102, serving as supplementary bubbles for the gas layer exiting through the upper vent 101, making the gas layer more uniform. This also avoids the bifurcation and breakage of the gas layer that occurs when only a single vent is open, increasing the coverage area of the gas layer and enhancing the drag reduction effect. .
[0033] In a preferred embodiment of this utility model, to facilitate gas flow, the air inlet 107 can be a circular hole, the internal connecting hole 104 can be a horizontal elongated hole, the side vent 102 can be an elongated hole inclined to the rear, and the upper vent 101 can be a horizontal elongated hole opened laterally. Multiple upper vents 101 can be provided along the length of the hull.
[0034] In a preferred embodiment of this utility model, the base plate 1 is made of steel plate, with a front lifting port 105 at its head and a rear lifting hole 106 coaxially at its end. The base plate 1 is used to connect the device to the hull, and after the connection is completed, the bottom surface of the base plate 1 is conformal to the bottom surface of the hull.
[0035] This utility model's ventilation generating device has a side air chamber. After ventilation, the main air chamber outputs a continuous air layer from the upper air port. The side air chamber can uniformly generate stable bubbles, supplementing the continuous air layer output from the upper air port, making the air layer more uniform. Simultaneously, the bubbles output from the side air port can avoid the branching and breakage phenomenon that occurs when only a single air port is ventilated, increasing the coverage area of the air layer and enhancing the drag reduction effect. The above-described embodiments are merely a preferred solution of this utility model, and are not intended to limit the utility model. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this utility model. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this utility model.
Claims
1. A bubble generating device for air-lubricated, drag-reducing ships, characterized in that, It includes a main air chamber (11), a side air chamber (12), and an exhaust chamber (13) disposed on the base plate (1); The main air chamber (11) is located on the bottom plate (1) connected to the outer plate of the ship. The top is connected to the external air supply equipment through the air inlet (107). Side air chambers (12) are symmetrically provided on the left and right sides. The main air chamber (11) and the side air chambers (12) are connected through the internal connecting hole (104). The exhaust chamber (13) is an open cavity located below the main air chamber (11) and can be in direct contact with the water flow. The head end of the exhaust chamber (13) is connected to the main air chamber (11) through the upper air inlet (101), and the two sides are connected to the two side air chambers (12) through the side air inlets (102) respectively. The bottom of the head end of the exhaust chamber (13) is provided with an air storage cover plate (103), which is used to guide the gas flowing out from the upper air inlet (101) to flow towards the rear of the ship.
2. The bubble generating device for air-lubricated and drag-reducing ships according to claim 1, characterized in that, The bottom surface of the bottom plate (1) is conformal to the bottom surface of the hull.
3. A bubble generating device for air-lubricated, drag-reducing ships according to claim 1, characterized in that, Two side plates are symmetrically installed on the upper surface of the base plate (1), with the head ends of the two side plates joined together and the tail ends separated. A top plate and an exhaust chamber top wall (109) are provided between the two side plates near the head end. The top plate is located above the exhaust chamber top wall (109) and there is a gap between the two. A rear side wall is provided behind the top plate and the exhaust chamber top wall (109). The tail side of the exhaust chamber top wall (109) is smoothly connected to the base plate (1) through an inclined exhaust chamber rear wall (108). A cover plate is fixed on the outer side of each side plate. The cover plate and the connected side plate form a closed area and serve as a side air chamber (12). The two side plates, the top plate, the exhaust chamber top wall (109) and the rear side wall together form the main air chamber (11). The two side plates, the exhaust chamber top wall (109), the exhaust chamber rear wall (108) and the air storage cover plate (103) together form a semi-closed exhaust chamber (13).
4. A bubble generating device for air-lubricated, drag-reducing ships according to claim 3, characterized in that, The side plate is perpendicular to both the bottom plate (1) and the top plate.
5. A bubble generating device for air-lubricated, drag-reducing ships according to claim 3, characterized in that, An air inlet (107) is provided on the top plate, an internal connecting hole (104) and a side vent (102) are provided on the side plate, and an upper vent (101) is provided on the top wall (109) of the exhaust chamber.
6. A bubble generating device for air-lubricated, drag-reducing ships according to claim 3, characterized in that, The air storage cover (103) is located on the bottom surface of the joint at the head end of the two side plates, and its vertical projection can cover all the upper vents (101).
7. A bubble generating device for air-lubricated, drag-reducing ships according to claim 1, characterized in that, The air inlet (107) is a circular hole, the internal connecting hole (104) is a horizontal elongated hole, the side vent (102) is an elongated hole that slopes backward, and the upper vent (101) is a horizontal elongated hole that opens laterally.
8. A bubble generating device for air-lubricated, drag-reducing ships according to claim 1, characterized in that, The upper vent (101) is provided with multiple vents along the length of the hull.
9. A bubble generating device for air-lubricated, drag-reducing ships according to claim 1, characterized in that, The bottom plate (1) is made of marine steel plate, with a front lifting port (105) at the head end and a rear lifting hole (106) coaxially at the end.
10. A bubble generating device for air-lubricated, drag-reducing ships according to claim 1, characterized in that, The exhaust chamber (13) is a two-section structure, with both the front and rear sections tilted backward, and the tilt angle of the rear section is greater than that of the front section; the height of the exhaust chamber (13) is the optimal turbulence height of the boundary layer.