Propeller front wake flow compensation guide pipe

Abstract

The utility model provides a wake compensation conduit in front of a propeller. The wake compensation conduit comprises a connecting plate, a left half tube and a right half tube. Wherein the front end of the connecting plate is fixedly connected with the stern. The upper edge of the left half pipe is fixedly connected with the left side of the connecting plate, and the lower edge is fixedly connected with the stern. The upper edge of the right half pipe is fixedly connected with the right side of the connecting plate, and the lower edge is fixedly connected with the stern. And the front ends of the left half pipe and the right half pipe are provided with zigzag structures to jointly form front edge sawteeth of the front wake compensation guide pipe of the propeller. The front end of the left half pipe and the front end of the right half pipe jointly define a water inlet of the propeller front wake flow compensation guide pipe, the rear end of the left half pipe and the rear end of the right half pipe jointly define a water outlet of the propeller front wake flow compensation guide pipe, and water flows into a water flow channel in the propeller front wake flow compensation guide pipe from the water inlet and flows out from the water outlet. According to the technical scheme, by arranging the front edge sawteeth, flow separation can be delayed or restrained, the inflow condition of the propeller is improved, and the working efficiency of the propeller is improved.

Description

Technical Field

[0001] This application relates to the field of shipbuilding, and more specifically, to a propeller front wake compensation duct. Background Technology

[0002] Today, the world is increasingly focused on low-carbon, energy-saving, and green environmental protection concepts. Ships, as one of the main modes of transportation globally, consume enormous amounts of fossil fuels and emit large quantities of greenhouse gases and other pollutants. Therefore, reducing ship fuel consumption is of great significance. The propeller wake compensation duct is a commonly used ship energy-saving device. It is typically installed at the stern near the stern shaft to rectify the wake at the stern, increasing the velocity of the incoming flow in front of the propeller, reducing flow separation at the stern, and improving propeller propulsion efficiency. This reduces fuel consumption and carbon emissions during ship navigation, achieving energy conservation and emission reduction goals, and effectively lowering ship operating costs.

[0003] However, in existing technologies, the flow field environment considered when designing propeller wake compensation ducts is usually quite ideal. In reality, ships experience changes in their navigation state during navigation, such as the difference in displacement between unloaded and fully loaded conditions. When unloaded, the propeller and energy-saving device are closer to the water surface and are easily affected by waves, causing the energy-saving device to deviate from the ideal design conditions. For example, a large angle of attack at the inlet of the compensation duct can cause flow separation, leading to poorer inlet flow conditions for the propeller and reduced efficiency. Especially in extreme sea states (such as high winds and waves), a large angle of attack often occurs at the inlet of the compensation duct, and existing compensation ducts typically do not specifically consider these factors in their design, further reducing their actual effectiveness. Therefore, existing propeller wake compensation ducts have significant limitations in practical applications and cannot adequately meet the energy-saving requirements of ships under various complex sea conditions and different navigation states. Utility Model Content

[0004] The purpose of this application is to provide a propeller front flow compensation duct, which, by setting a leading edge serration, can delay or suppress the occurrence of flow separation, effectively improve the propeller inlet conditions, and enhance the propeller's working efficiency.

[0005] This application provides a propeller front wake compensation duct, including a connecting plate, a left half-pipe, and a right half-pipe. The front end of the connecting plate is fixedly connected to the stern. The upper edge of the left half-pipe is fixedly connected to the left side of the connecting plate, and the lower edge is fixedly connected to the stern. The upper edge of the right half-pipe is fixedly connected to the right side of the connecting plate, and the lower edge is fixedly connected to the stern. Both the front ends of the left and right half-pipes have serrated structures, collectively forming the leading edge serrations of the propeller front wake compensation duct. The front ends of the left and right half-pipes together form the inlet of the propeller front wake compensation duct, and the rear ends of the left and right half-pipes together form the outlet of the propeller front wake compensation duct. In use, water flows from the inlet into the internal water flow channel of the propeller front wake compensation duct and flows out from the outlet.

[0006] In one feasible embodiment, the top of each tooth in the leading edge serration is a planar structure, and the bottom of each tooth groove is a planar structure.

[0007] In one feasible embodiment, the top of each tooth in the leading edge serration is a pointed structure, and the bottom of each tooth groove is a planar structure.

[0008] In one feasible embodiment, the top of each tooth in the leading edge serration is a pointed structure, and the bottom of each tooth groove is a planar structure.

[0009] In one feasible scheme, the cross-section of the water flow channel gradually decreases from front to back along the axial direction of the ship's propeller shaft.

[0010] In one feasible scheme, at any cross-section of the water flow channel, the diameter of the left half of the pipe is different from that of the right half.

[0011] In one feasible solution, the walls of both the left and right halves of the tube are thicker in the middle and thinner at both ends along the axis of the ship's propeller shaft.

[0012] In one feasible scheme, the angle between the plane where the outlet is located and the plane where the inlet is located is an acute angle, and the distance between the upper end of the outlet and the inlet is greater than the distance between the lower end of the outlet and the inlet.

[0013] In one feasible scheme, the central axis of the left half-pipe and the central axis of the right half-pipe are respectively angled at 0-30° with the axis of the ship's propeller shaft.

[0014] In one feasible solution, the front end of the connecting plate is provided with a notch for fixed connection to the stern.

[0015] Compared with the prior art, the beneficial effects of this application include at least the following:

[0016] This application provides a propeller front wake compensation duct with leading-edge serrations. During ship navigation, when the incoming flow angle is large, the leading-edge serrations can disrupt the original streamline distribution, generating a series of small-scale eddies. These eddies can enhance the stability of the boundary layer, delaying or suppressing flow separation, thereby effectively improving the propeller's inlet conditions and thus increasing its efficiency. Especially in extreme sea states such as high winds and waves, the waves cause the ship to oscillate significantly, resulting in a large angle of attack between the propeller's front wake compensation duct inlet and the incoming flow. The leading-edge serrations are particularly effective at suppressing flow separation under such large angles of attack, thus effectively improving the propeller's inlet conditions and increasing its efficiency under extreme sea conditions.

[0017] Furthermore, this application provides various leading-edge sawtooth design schemes, which can better adapt the propeller front wake compensation duct to different vessels and achieve better working results for different vessels. In addition, the cross-sectional area of ​​the water flow channel of the propeller front wake compensation duct provided in this application gradually decreases from front to back along the axial direction of the propeller shaft, which can promote an increase in water flow velocity, thereby forming a more uniform and high-speed inflow in front of the propeller, providing more ideal operating conditions for the propeller, and further improving the propeller's working efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of a propeller front wake compensation duct installed at the stern, according to an embodiment of this application.

[0020] Figure 2 A rear view of the propeller wake compensation duct installed at the stern;

[0021] Figure 3 A bottom view of the propeller wake compensation duct installed at the stern;

[0022] Figure 4 A side view of the propeller front flow compensation duct;

[0023] Figure 5 Schematic diagrams showing different leading edge serrations;

[0024] Figure 6This is a schematic diagram showing that the centerlines of the left and right halves of the tube form angles with the axis of the propeller shaft.

[0025] In the diagram: 1. Connecting plate; 2. Left half pipe; 3. Right half pipe; 4. Leading edge serrations; 5. Stern; 6. Inlet; 7. Outlet; 8. Water flow channel. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] like Figures 1-4 As shown, this application provides a propeller front wake compensation duct, including a connecting plate 1, a left half-pipe 2, and a right half-pipe 3. The connecting plate 1 is strip-shaped, with its front end fixedly connected to the stern 5. A notch can be provided at the front end of the connecting plate 1 for fixed connection to the stern 5. The upper edge of the left half-pipe 2 is fixedly connected to the left side of the connecting plate 1, and its lower edge is fixedly connected to the stern 5. The upper edge of the right half-pipe 3 is fixedly connected to the right side of the connecting plate 1, and its lower edge is fixedly connected to the stern 5. Both the front ends of the left half-pipe 2 and the right half-pipe 3 have serrated structures, collectively forming the leading edge serration 4 of the propeller front wake compensation duct. The front ends of the left half-pipe 2 and the right half-pipe 3 together form the inlet 6 of the propeller front wake compensation duct, and the rear ends of the left half-pipe 2 and the right half-pipe 3 together form the outlet 7 of the propeller front wake compensation duct.

[0029] In operation, water flows from the inlet 6 into the water flow channel 8 inside the propeller's forward flow compensation duct and exits from the outlet 7. Preferably, the cross-section of the water flow channel 8 gradually decreases from front to back along the axis of the propeller shaft. Specifically, the radius of the inlet 6 can be set to 0.3-0.6 times the propeller radius, and the radius of the outlet 7 can be set to 0.2-0.5 times the propeller radius. This tapering design allows the water flow velocity to gradually increase as it passes through the channel 8, reducing flow separation and eddy current generation. This creates a high-speed and stable water flow in front of the propeller, improving the propeller's inflow quality and reducing energy loss, further enhancing the efficiency of the entire propulsion system.

[0030] The propeller wake compensation duct of this application features a leading-edge serration at its front end. During ship navigation, when the incoming flow angle is large, the leading-edge serration can disrupt the original streamline distribution, generating a series of small-scale vortices. These vortices can enhance the stability of the boundary layer, delaying or suppressing flow separation, thereby effectively improving the propeller's inlet conditions and thus increasing its efficiency. Especially in extreme sea states such as high winds and waves, the waves cause the ship to oscillate significantly, resulting in a large angle of attack between the propeller wake compensation duct inlet and the incoming flow. The leading-edge serration's effect in suppressing flow separation under such large angles of attack is particularly pronounced. Therefore, it can effectively improve the propeller's inlet conditions and increase its efficiency under extreme sea conditions.

[0031] Furthermore, this application provides various leading-edge sawtooth design schemes, which can better adapt the propeller front wake compensation duct to different vessels and achieve better working results for different vessels. In addition, the cross-sectional area of ​​the water flow channel of the propeller front wake compensation duct provided in this application gradually decreases from front to back along the axial direction of the propeller shaft, which can promote an increase in water flow velocity, thereby forming a more uniform and high-speed inflow in front of the propeller, providing more ideal operating conditions for the propeller, and further improving the propeller's working efficiency.

[0032] In one embodiment, leading edge serrations 4 with different structures can be used depending on the actual needs of the ship. For example... Figure 5As shown, commonly used leading-edge sawtooth schemes include leading-edge sawtooth scheme 1, leading-edge sawtooth scheme 2, and leading-edge sawtooth scheme 3. In leading-edge sawtooth scheme 1, the top of each sawtooth is a planar structure, the bottom of each tooth groove is a planar structure, the distance between the roots of adjacent sawtooths can be set to 1-3° of the circumferential length of the inlet 6, the tooth length of the sawtooth can be set to 4-8° of the circumferential length of the inlet 6, and the included angle between the sides of adjacent sawtooths can be set to 30-75°. In leading-edge sawtooth scheme 2, the top of each sawtooth is a pointed structure, the bottom of each tooth groove is a planar structure, the distance between the roots of adjacent sawtooths can be set to 1-3° of the circumferential length of the inlet 6, and the tooth length of the sawtooth can be set to 4-8° of the circumferential length of the inlet 6. In leading-edge sawtooth scheme 3, the top of each sawtooth is a pointed structure, and the bottom of each tooth groove is a planar structure. The tooth length of the saw teeth can be set to 4-8° of the circumferential length of the inlet 6, the tooth tip length of each saw tooth can be set to 0.2-0.5 of the tooth root length, and the included angle between the sides of adjacent saw teeth can be set to 30-75°.

[0033] In comparison, the leading-edge sawtooth scheme 1 performs better under medium angles of attack, effectively suppressing flow separation and smoothing the propeller flow, thus improving propeller efficiency. However, its performance under large angles of attack is relatively average. The leading-edge sawtooth scheme 2 performs best under large angles of attack, but its performance under medium angles of attack is relatively average. The leading-edge sawtooth scheme 3 performs well under medium angles of attack and maintains a certain level of performance under large angles of attack, exhibiting a more balanced overall performance. Therefore, the leading-edge sawtooth scheme 1 is more suitable for small and medium-sized vessels and routine navigation in general sea states; the leading-edge sawtooth scheme 2 is more suitable for large vessels, vessels frequently facing severe sea states, and vessels with extremely high energy-saving requirements; while the leading-edge sawtooth scheme 3 is suitable for medium-sized vessels, vessels with certain energy-saving requirements, and vessels needing to adapt to various sea states. In actual production, the most suitable leading-edge sawtooth scheme can be selected based on the vessel's actual needs and navigation environment to achieve the best energy-saving effect and economic benefits.

[0034] In one embodiment, at any cross-section of the water flow channel 8, the diameter of the left half of the pipe 2 is different from the diameter of the right half of the pipe 3, such as... Figure 2 As shown, the cross-section of the left half-pipe 2 is smaller than that of the right half-pipe 3. During ship navigation, the wake field at the stern often exhibits a certain degree of asymmetry, which may affect the propeller's inflow quality. The water flow channel 8 adopts an asymmetric design to compensate for and optimize this asymmetric wake field. For example, the smaller cross-section of the left half-pipe 2 significantly accelerates the water flow, thus balancing the flow velocity in the right half to some extent. This design makes the inflow in front of the propeller more uniform, reducing uneven stress on the propeller blades caused by the asymmetry of the wake field and improving the propeller's propulsion efficiency.

[0035] In one embodiment, the walls of both the left half-pipe 2 and the right half-pipe 3 are thicker in the middle and thinner at both ends along the axis of the ship's propeller shaft, i.e., the walls of the left half-pipe 2 and the right half-pipe 3 are airfoil-shaped. This design can effectively reduce water flow resistance, enhance boundary layer stability, reduce flow separation and eddy generation, thereby further optimizing the flow field, providing a more uniform and stable inflow for the propeller, and also enhancing the tube's resistance to pressure and deformation, ensuring long-term stable operation of the water flow channel. Alternatively, the walls of the left half-pipe 2 and the right half-pipe 3 can also be shaped like airfoils, slots, or rhombuses, depending on the specific circumstances; no further restrictions are imposed here.

[0036] In one embodiment, the angle between the plane where the outlet 7 is located and the plane where the inlet 6 is located is an acute angle, and the distance between the upper end of the outlet 7 and the inlet 6 is greater than the distance between the lower end of the outlet 7 and the inlet 6. For example... Figure 4 As shown, this design positions the outlet 7 at a downward angle. Specifically, the angle α between the outlet 7 and the inlet 6 can be set to 0-30°. Since the connecting plate 2 is installed above the propeller shaft (typically, the vertical distance between the connecting plate 2 and the propeller shaft is 0.4-0.6 times the propeller radius), this design allows the water flow at the outlet 7 to be directed towards the downward-sloping propeller mounting position, thus making fuller use of the water flow by the propeller. Generally, the longest distance between the outlet 7 and the inlet 6 along the axis of the propeller shaft can be set to 0.2-0.6 times the propeller radius.

[0037] In one embodiment, such as Figure 6 As shown, the central axis of the left half-pipe 2 and the central axis of the right half-pipe 3 can be set at an angle of 0-30° to the axis of the ship's propeller shaft. Accordingly, the connecting plate 1 can be trapezoidal in shape to connect with the left half-pipe 2 and the right half-pipe 3. This design helps to expand the effective area of ​​the propeller front wake compensation duct, allowing it to guide a wider range of water flow.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A propeller front flow compensation duct, characterized in that, include: Connecting plate (1), the front end of which is fixedly connected to the stern (5); The left half-pipe (2) has its upper edge fixedly connected to the left side of the connecting plate (1) and its lower edge fixedly connected to the stern (5); The right half-pipe (3) has its upper edge fixedly connected to the right side of the connecting plate (1) and its lower edge fixedly connected to the stern (5); The front end of the left half-pipe (2) and the front end of the right half-pipe (3) are both provided with a serrated structure, which together form the leading edge serration (4) of the propeller front flow compensation duct. The front end of the left half-pipe (2) and the front end of the right half-pipe (3) together form the inlet (6) of the propeller front flow compensation duct, and the rear end of the left half-pipe (2) and the rear end of the right half-pipe (3) together form the outlet (7) of the propeller front flow compensation duct. In use, water flows from the inlet (6) into the water flow channel (8) inside the propeller front flow compensation duct and flows out from the outlet (7).

2. The propeller front flow compensation duct according to claim 1, characterized in that, In the leading edge saw teeth (4), the top of each saw tooth is a planar structure, and the bottom of each tooth groove is a planar structure.

3. The propeller front flow compensation duct according to claim 1, characterized in that, In the leading edge saw teeth (4), the top of each saw tooth is a pointed structure, and the bottom of each tooth groove is a planar structure.

4. The propeller front flow compensation duct according to claim 1, characterized in that, In the leading edge saw teeth (4), the top of each saw tooth is a pointed structure, and the bottom of each tooth groove is a planar structure.

5. The propeller front flow compensation duct according to claim 1, characterized in that, The cross-section of the water flow channel (8) gradually decreases from front to back along the axis of the ship's propeller shaft.

6. The propeller front flow compensation duct according to claim 1, characterized in that, At any cross-section of the water flow channel (8), the diameter of the left half pipe (2) is different from that of the right half pipe (3).

7. The propeller front flow compensation duct according to claim 1, characterized in that, The walls of the left half-pipe (2) and the right half-pipe (3) are both thicker in the middle and thinner at both ends along the axis of the ship propeller shaft.

8. The propeller front flow compensation duct according to claim 1, characterized in that, The angle between the plane where the outlet (7) is located and the plane where the inlet (6) is located is an acute angle, and the distance between the upper end of the outlet (7) and the inlet (6) is greater than the distance between the lower end of the outlet (7) and the inlet (6).

9. The propeller front flow compensation duct according to claim 1, characterized in that, The central axis of the left half-pipe (2) and the central axis of the right half-pipe (3) are respectively at an angle of 0-30° with the axis of the ship propeller shaft.

10. The propeller front flow compensation duct according to claim 1, characterized in that, The front end of the connecting plate (1) is provided with a notch for fixed connection with the stern (5).

Images