Device for reducing propulsion power demand of watercraft

Abstract

The invention describes a device for reducing the propulsive power demand of a watercraft, in particular a vessel, and arranged in front of the propeller of the vessel in the direction of water flow, comprising a flow guide surface, in particular a nozzle ring or partial nozzle ring, at least one inner fin protruding from the flow guide surface; and at least one outer fin protruding from the flow guide surface, where when the device is mounted on the watercraft, one end of the inner fin is fixed to the flow guide surface and the other end is attached to the watercraft; one end of the flow guide surface outer fin is attached to the flow guide surface, the other end of the flow guide surface outer fin forms a free end, and the at least one inner fin and / or the at least one outer fin are / is made of a composite material.

Description

[0001] This invention relates to a device for reducing the propulsion power requirements of watercraft (especially ships) and arranged ahead of a propeller along the direction of water flow. The device includes a guide surface (especially a nozzle ring or partial nozzle ring), at least one inner fin protruding from the guide surface, and at least one outer fin protruding from the guide surface. When the device is mounted on the watercraft, one end of the inner fin is fixed to the guide surface, and the other end is fixed to the watercraft; one end of the outer fin is fixed to the guide surface, and the other end forms a free end. Furthermore, the invention also relates to a device including the aforementioned device, a propeller, and a rudder, and a ship having the device. Background Technology

[0002] EP 2 591 994 A1 discloses a device as described above. This device, used to reduce the propulsion power requirements of watercraft, includes a front nozzle, wherein at least one external fin protrudes outward from the front nozzle. Furthermore, the illustrated device may also have an internal fin, with a first end fixed to the inner wall of the front nozzle and a second end fixed to a bearing, particularly to the tail tube.

[0003] Devices in this type of known technology used to reduce the propulsion power requirements of watercraft are typically installed on ships, viewed from the ship's direction of travel, particularly at a short distance or directly in front of the propeller. Furthermore, fins are attached to the nose nozzle, designed as guide fins or lifting wings. The nose nozzle is essentially a shallow truncated cone shape with two openings, an inlet and an outlet, both largely circular, with the inlet diameter larger than the outlet. This improves propeller performance and, through the fins mounted on the nose nozzle, selectively generates pre-spin, thereby reducing losses in the propeller jet. Such a system can significantly reduce propulsion power requirements, thus saving fuel. These known devices are typically made entirely of steel.

[0004] Summary of the Invention: Objective, Solution, Advantages

[0005] This invention aims to further improve a device for reducing the propulsion power requirements of watercraft, the device comprising a guide surface, at least one inner fin, and at least one outer fin. In particular, the energy efficiency of the device is further improved.

[0006] To address this, a device is provided for reducing the propulsion power requirements of watercraft (especially ships), and is arranged in front of the ship's propeller along the direction of water flow. The device includes a guide surface, particularly a nozzle ring or partial nozzle ring, at least one inner fin protruding from the guide surface, and at least one outer fin protruding from the guide surface. When the device is installed on the watercraft, one end of the inner fin is attached to the guide surface, and the other end is attached to the watercraft; one end of the outer fin is attached to the guide surface, while the other end forms a free end.

[0007] According to the invention, a further embodiment is provided in which the at least one inner fin and / or at least one outer fin is made of a composite material. The use of a composite material for the at least one inner fin and / or at least one outer fin reduces the weight of the device, thereby improving its energy efficiency. Due to the excellent strength properties of composite materials, sufficient strength to withstand the loads and stresses experienced by the device during operation can be achieved simultaneously. This is particularly evident for the at least one outer fin made of a composite material, which withstands the highest bending stress among all components of the device due to its free-end design. Furthermore, the use of composite materials facilitates the formation of at least one outer fin and / or at least one inner fin with a hydrodynamically advantageous bending profile.

[0008] In this paper, composite materials should be understood as mixtures composed of two or more pure matrix materials. The matrix materials constituting a composite material are firmly and inseparably bonded together.

[0009] The guide surface can be designed as a single piece or a combination of multiple individual components, which are preferably welded together or welded to the hull.

[0010] The guide surface can generally have different shapes. The arrangement and design of the guide surface ensures that the water flow is at least partially guided to the propeller. For example, the guide surface can have the shape of a square or rectangular plate. However, a curved or arc-shaped construction is preferred. In cross-section, a curved guide surface can have a circular, arc-shaped, elliptical arc, or other curved shape. The guide surface has a length in the direction of water flow, i.e., the direction of travel of the water vehicle. Furthermore, a plate-shaped guide surface has a width, or an arc-shaped guide surface has an arc length. The thickness of the guide surface is referred to below as profile thickness. Whether it is the length, width, arc length, or profile thickness, it can remain constant or have different values ​​throughout the guide surface area. For example, the guide surface can also form a certain profile. In this case, for example, the edges of the guide surface can be designed with rounded corners and have a smaller profile thickness than the central area of ​​the guide surface.

[0011] Particularly preferred is that the flow guide surface is designed as a nozzle ring or a partial nozzle ring. In the nozzle ring configuration, the flow guide surface is circumferentially closed, while in the partial nozzle ring configuration, it is circumferentially open. Preferably, the partial nozzle ring embodiment has a cross-section of one-eighth ring, one-quarter ring, half ring, two-thirds ring, or three-quarters ring. In the partial nozzle ring embodiment, in the cross-sectional view, the arc length of the flow guide surface is preferably less than 80% of the theoretically circumferentially closed nozzle ring circumference, more preferably less than 60%, and particularly preferably less than 40% or 30%. Furthermore, preferably, in the installed state, the flow guide surface at least partially surrounds the propeller shaft of the ship's propeller circumferentially.

[0012] Preferably, the guide surface is arranged in front of the propeller. This means that the guide surface is positioned in front of the propeller of the watercraft or vessel in the direction of travel. The phrase "in the direction of travel" here should be understood as the forward direction of the vessel or watercraft.

[0013] Preferably, the guide surface is arranged at a certain distance from the propeller. Furthermore, preferably, the guide surface is arranged at a certain distance from the ship's bearings, particularly the stern tube. The stern tube supports the propeller shaft of the ship or watercraft. For this purpose, the guide surface can be arranged at least partially above, below, or to the side of the propeller shaft. Additionally, the guide surface can also at least partially surround the propeller shaft or bearing.

[0014] Preferably, the guide surface is arranged above the propeller shaft or thruster shaft and at a certain distance from it.

[0015] The first end of the at least one outer fin is connected to or attached to the guide surface in a suitable manner. The second end of the at least one outer fin is designed as a free end. Therefore, the at least one outer fin can protrude from the guide surface in any direction, wherein the second end of the at least one outer fin is not connected to the guide surface or otherwise fixed to the hull. Preferably, the at least one outer fin protrudes radially outward from the guide surface, i.e., away from the stern tube.

[0016] The first end of the at least one inner fin is suitably connected to or attached to the guide surface. Preferably, the at least one inner fin protrudes inward from the guide surface, i.e., toward the ship's bearings or stern tube. When the device is mounted on a watercraft, the second end of the at least one inner fin is configured to attach to the watercraft, particularly in the stern tube region. Preferably, the at least one inner fin protrudes radially inward from the guide surface.

[0017] "Fin" should be understood as a guide vane or support fin, preferably fixedly arranged on a guide surface. Here, "fin" can be understood as any guiding device that affects the propeller inlet flow, wherein the fin preferably has an airfoil profile, i.e., including a suction surface and a pressure surface. Therefore, in this document, the fin serves as a guide surface of the stator, arranged on said guide surface and influencing the propeller inlet flow. Particularly preferred are fins having an outwardly curved (especially circular arc) suction surface and a substantially flat pressure surface.

[0018] The profile of the at least one inner fin and / or at least one outer fin may be uniform or non-uniform along its length. In particular, the profile may be rotationally twisted along the length direction of the at least one inner fin and / or at least one outer fin.

[0019] The at least one inner fin and at least one outer fin can be formed independently and attached to the guide surface respectively. In another embodiment, the at least one inner fin and at least one outer fin can also be made as a single piece, in which case the single piece extends through the guide surface. Furthermore, the at least one outer fin and at least one inner fin can be arranged sequentially or staggered in the radial direction.

[0020] Preferably, a plurality of outer fins and / or a plurality of inner fins are provided. Particularly preferably, more than two outer fins and / or more than two inner fins are provided, and even more preferably, exactly three inner fins and / or exactly three outer fins are provided.

[0021] Preferably, the composite material is glass fiber reinforced plastic (GFRP), E-type composite material, E-glass, foam plastic, plastic, or carbon fiber, or a mixture thereof. Alternatively, as an alternative or supplement, the composite material preferably includes reinforcing non-metallic fibers, particularly Kevlar fibers, glass fibers, basalt fibers, ceramic fibers, aramid fibers, or carbon fibers. Kevlar fibers are particularly preferred as reinforcing non-metallic fibers. Through these preferred embodiments, high and sufficient strength of the at least one outer fin and / or at least one inner fin is advantageously ensured.

[0022] Preferably, the guide surface is made of metal, particularly steel. Furthermore, it is preferred that at least one inner fin (particularly preferred, all inner fins) is made of metal, particularly steel. In this preferred embodiment, the guide surface and inner fins are made of metal, therefore only the at least one outer fin (preferably all outer fins) is made of a composite material. The outer fins bear particularly high bending loads, therefore, the use of composite materials (particularly when the material is fiber-reinforced) is particularly advantageous for the outer fins. For the inner fins, high strength is important, therefore, it may be advantageous for them to be made of steel.

[0023] Preferably, the flow guide surface has at least one fin mount, particularly made of metal, for mounting the at least one inner fin and / or the at least one outer fin made of composite material. Preferably, the fin mount is shaped to fit the mounting of the at least one inner fin and / or the at least one outer fin. Furthermore, preferably, the fin mount is fixedly connected to the flow guide surface, particularly by welding. Particularly preferred is that the fin mount is designed as a pipe fitting into which the end region of each of the at least one inner fin and / or the at least one outer fin can be inserted and then connected. The fin mount allows the at least one inner fin and / or the at least one outer fin made of composite material to be permanently and stably attached to the flow guide surface, particularly made of metal, in a simple and safe manner.

[0024] Preferably, the at least one inner fin made of composite material and / or the at least one outer fin made of composite material are connected to the flow guide surface and / or fin mount by riveting, bonding, screwing and / or welding.

[0025] Preferably, the composite material comprises reinforcing non-metallic fibers, wherein the at least one inner fin and / or the at least one outer fin made of the composite material has a connecting element at one end facing the flow guide surface. This connecting element comprises a hybrid textile structure made of reinforcing non-metallic fibers and at least one metallic fiber, wherein the metallic fiber is preferably selected from the group consisting of iron, steel, copper, bronze, aluminum, titanium, gold, and silver, and particularly preferably from steel, aluminum, and titanium. With such a connecting element, a stable connection can be securely formed between the flow guide surface and the at least one outer fin or the at least one inner fin.

[0026] The hybrid textile structure preferably extends longitudinally along the longitudinal direction of the at least one inner fin and / or at least one outer fin, wherein, preferably, there is a gradient of material composition in the longitudinal extension direction of the hybrid textile structure, such that the hybrid textile structure is composed of 50% to 100% metal fibers at one end facing the flow guide surface and 50% to 100% non-metal fibers at the other end.

[0027] Furthermore, the connecting element preferably has a metal connector that is bonded to the end material of the hybrid textile structure facing the flow guide surface, preferably by welding or brazing. This connector allows the connecting element to be easily connected to the flow guide surface, particularly one made of metal, especially through welding.

[0028] Furthermore, the basic objective of the invention is achieved by a marine device comprising the aforementioned apparatus, a propeller with a propeller shaft, and a rudder located downstream of the propeller in the direction of water flow, wherein the apparatus is located upstream of the propeller in the direction of water flow and at least partially surrounds the propeller shaft. To partially surround the propeller shaft, the guide surface of the apparatus is advantageously designed as a nozzle ring or a partial nozzle ring.

[0029] Ultimately, the basic task of this invention can also be achieved by a ship that includes the aforementioned equipment.

[0030] Brief description of the attached figures

[0031] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings schematically illustrate:

[0032] Figure 1 : A perspective view of the apparatus according to an embodiment of the present invention;

[0033] Figure 2a 2b: Top view and side view of the device according to an embodiment of the present invention;

[0034] Figure 3 Front view of the device according to an embodiment of the present invention along the inflow direction;

[0035] Figure 4 A cross-sectional view of an apparatus demonstrating inner and outer fins according to an embodiment of the present invention; and

[0036] Figure 5 : A fin mounting base according to an embodiment of the present invention.

[0037] Detailed description of the attached figures

[0038] Figure 1A perspective view of an apparatus according to an embodiment of the invention is shown, providing a simplified manufacturing method for the hydrodynamically advantageous curved profile of the outer fins 120. The apparatus 100 includes a flow guide surface 110 and a plurality of outer fins 120a, 120b, 120c (three in total) and inner fins 130a, 130b, 130c (three in total). The outer fins 120a, 120b, 120c are fixed to the flow guide surface 110 by fin mounting seats 140, each outer fin 120a, 120b, 120c having its own fin mounting seat 140. The apparatus 100 is configured to be mounted in the direction of water flow ahead of a ship's stern propeller (not shown). In particular, the ends of the inner fins 130a, 130b, 130c away from the flow guide surface 110 are configured to be attached and fixed to the ship, particularly to the stern tube, especially by welding. For this purpose, the inner fins 130a, 130b, 130c and the guide surface 110 are made entirely of metal, particularly steel. The guide surface is configured as a partial nozzle ring, preferably partially surrounding the propeller shaft in the installed state. The arc angle of this partial nozzle ring is between 90° and 120°. Preferably, the finned partial nozzle ring is located between 8 o'clock and 1 o'clock relative to the direction of propeller rotation (viewed from the stern of the ship) to accelerate the propeller inflow and generate a reverse vortex to compensate for the vortex generated by the propeller. For this purpose, the outer fins and / or inner fins preferably have a curved profile. The inner fins 130a, 130b, 130c extend substantially radially inward from the guide surface 110. The outer fins 120a, 120b, 120c extend substantially radially outward from the guide surface 110 and are arranged radially behind the corresponding inner fins 130a, 130b, 130c. The outer fins 120a, 120b, and 120c are made of composite materials, particularly fiber composite materials. Using composite materials to make the outer fins 120a, 120b, and 120c reduces weight and makes it easier to manufacture the hydrodynamically advantageous curved profile of the outer fins 120.

[0039] Figure 2a and 2b A side view is shown. Figure 3 Showing Figure 1 The front view of the device 100 shown. Figure 2a Display device 100 from above, Figure 2b Viewed from the port side. Figure 3 This is a view of the display device 100 in the direction of fluid inflow. Specifically, the figure shows that the profiles of the outer fins 120a, 120b, and 120c can be different to achieve optimal vortex reduction. Furthermore, in... Figure 3 As can be seen, an inwardly protruding support rib 131 is provided at one end of the guide surface. This support rib 131 is used to fix the device 100 to the ship and to ensure the robustness and stability of the device 100. It does not typically have an airfoil profile.

[0040] Figure 4 A longitudinal section along the inventive device is shown. In particular, it is shown how the outer fin 120 is attached to the guide surface using the fin mounting part 140.

[0041] Figure 5 The attachment method of the outer fin 120 is shown in detail. The outer fin 120 is inserted into the fin mount 140 and is fixed by the fin mount 140 in a form-fit manner. Furthermore, the outer fin 120 is fixed to the fin mount 140 by bolts 150 passing through both the fin mount 140 and the outer fin 120. Alternatively, the outer fin 120 can also be attached to the fin mount 140 by adhesive or welding. For better attachment to the fin mount, the end of the outer fin facing the fin mount is preferably made of metal, particularly preferably iron, steel, copper, bronze, aluminum, titanium, gold, or silver, and especially preferably steel, aluminum, or titanium. In particular, the composite material may contain non-metallic fibers, and the outer fin made of the composite material may have a connecting element at its flow-guiding end, which comprises a hybrid textile structure made of non-metallic fibers and at least one metallic fiber. Here, the metal fibers can be selected from the group consisting of iron, steel, copper, bronze, aluminum, titanium, gold, and silver, preferably from steel, aluminum, and titanium, and especially preferably from steel. Preferably, the outer fins also have metal connectors that are combined with the end material of the mixed textile structure facing the flow guide surface 110, preferably by welding or brazing.

[0042] List of reference numerals

[0043] 100 devices

[0044] 110 guide surface

[0045] 120, 120a-120c outer fins

[0046] 130, 130a-130c Inner fin

[0047] 131 support ribs

[0048] 140 Fin Mount

[0049] 150 bolts

Claims

1. A device (100) for reducing the propulsion power requirement of water transport vehicles, especially ships, the device being arranged in the direction of water flow in front of the ship's propeller, the device comprising: The guide surface (110), especially the nozzle ring or part of the nozzle ring, At least one inner fin (130) protruding from the guide surface, wherein one end of the inner fin (130) is attached to the guide surface (110), and the other end of the inner fin (130) is attached to the water transport vehicle when the device is mounted on the water transport vehicle, and At least one external fin (120) protruding from the flow guide surface, wherein one end of the external fin (120) is attached to the flow guide surface and the other end of the external fin (120) forms a free end; Its features are, The at least one inner fin (120) and / or at least one outer fin (130) are made of composite material.

2. The apparatus according to claim 1, wherein the composite material comprises glass fiber reinforced plastic (GFRP), type E composite material, grade E glass fiber, foam material, plastic or carbon fiber, and / or wherein the composite material comprises reinforcing non-metallic fibers, particularly Kevlar fiber, glass fiber, basalt fiber, ceramic fiber, aramid fiber or carbon fiber, especially preferably Kevlar fiber.

3. The device according to claim 1 or 2, wherein the guide surface (110) is made of metal, particularly steel; preferably, the at least one inner fin (130), particularly all the inner fins (130a-d), is made of metal, particularly steel; preferably, the at least one outer fin (120), particularly all the outer fins (130a-c), is made of composite material.

4. The apparatus according to any of the preceding claims, wherein the flow guide surface (110) has at least one fin mount (140) for mounting the at least one inner fin (130) made of composite material and / or the at least one outer fin (120) made of composite material, wherein the fin mount (140) is in particular made of metal.

5. The apparatus of claim 4, wherein the at least one fin mount (140) is configured as a pipe joint, and the end of each of the at least one inner fin (130) and / or at least one outer fin (120) is inserted into and connected to the pipe joint.

6. The apparatus according to any of the preceding claims, wherein the at least one inner fin (130) made of a composite material and / or the at least one outer fin (120) made of a composite material are connected to the flow guide surface and / or fin mount (140) by bolts (150), adhesive and / or welding.

7. The apparatus according to any one of the preceding claims, wherein the composite material comprises non-metallic fibers, and the at least one inner fin (130) made of the composite material and / or the at least one outer fin (120) made of the composite material have a connecting element at one end facing the flow-guiding surface (110), the connecting element comprising a hybrid textile structure made of non-metallic fibers and at least one metallic fiber.

8. The apparatus according to claim 7, wherein the hybrid textile structure has a longitudinal extension along the longitudinal direction of the at least one inner fin (130) and / or at least one outer fin (120), and there is a gradient in material composition along the longitudinal extension of the hybrid textile structure, such that one end of the hybrid textile structure toward the flow guide surface (110) is formed of 50% to 100% metal fibers, while the other end is formed of 50% to 100% non-metal fibers.

9. The apparatus according to claim 7 or 8, wherein the metal fiber is selected from the group consisting of iron, steel, copper, bronze, aluminum, titanium, gold and silver, preferably selected from steel, aluminum and titanium, and particularly preferably steel.

10. The apparatus according to any one of claims 7 to 9, wherein the connecting element has a metal connector that is bonded to one end of the flow-guiding surface (110) of the mixed textile structure, preferably by welding or brazing.

11. The apparatus according to any of the preceding claims, wherein the at least one outer fin (120) extends continuously through the guide surface (110) as an inner fin (130), the inner fin (130) preferably being made of steel.

12. A type of ship equipment, comprising: The apparatus (100) according to any of the preceding claims; A propeller with a propeller shaft; The rudder, located downstream of the propeller along the direction of water flow, The device is characterized in that it is arranged upstream of the propeller along the direction of water flow and at least partially surrounds the propeller shaft.

13. A vessel comprising the equipment according to claim 12.

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