Rudder blade with modular structure, segment for a rudder blade or for a device for improving propulsion, and method for producing a rudder blade

Description

[0001] The present invention relates to a rudder blade for a rudder of a watercraft, in particular for a ship. Furthermore, the present invention relates to a segment for a rudder blade or for a device for improving propulsion, as well as to a method for producing a rudder blade. State of the art

[0002] Watercraft, especially ships, have a rudder, usually located at the stern, to change direction. A rudder for a watercraft comprises a rudder blade that is rotatably mounted on the ship's hull by means of a rudder shaft. Rudder blades, especially for semi-balanced or fully balanced rudders for watercraft such as container ships, oil tankers, trawlers, tugboats, ferries, or passenger ships, have a high overall weight. On large ships such as container ships or oil tankers, the total weight of the rudder can be well over 100 tons. Even on smaller ships such as trawlers, tugboats, or ferries, a weight in the double-digit ton range can be achieved.

[0003] From EP 1 921 005 B1 a rudder for propeller-driven ships is known, in which the propeller is arranged to rotate about a propeller axis, with a rudder blade and a flow body arranged on the rudder blade, wherein the pear-shaped or zeppelin-shaped flow body is arranged in the extension of the propeller axis in the region of the rudder blade and is designed to be self-destructive or self-dissolving in the event of increased force, impact, shock or pressure.

[0004] FR 1 128 161 A discloses a rudder blade with a fixed, two-part rudder shaft. The two sections of the rudder shaft are connected to a hub element. The hub element is covered with a metal cover that is also non-pivotable.

[0005] US 2016 / 0319668 A1 discloses a rudder, wherein a surface area of ​​the rudder is provided with a structured surface that reduces wear or erosion of the surface caused by a high-speed flow of a fluid containing abrasive particles. The structured surface comprises a plurality of grooves. The grooves are contacted by the high-speed flow of abrasive particles and alter or interrupt the flow of the fluid and abrasive particles, thereby reducing the surface wear rate or erosion of the leading edge of the structure.

[0006] JP H03-14793 A discloses a rudder for ships which has a plurality of vertical frames arranged between plates and whose side surfaces are covered with rudder plates.

[0007] From JP H03-7695 A a ship's rudder is known in which a cylindrical base body and a cylindrical body at the leading edge are tightly clamped by a preformed upper plate and a lower plate.

[0008] US 2005 / 0076819 A1 describes a method for reducing cavitation of underwater wings by introducing perforations into a wing profile.

[0009] Rudder blades are manufactured in a known manner by welding a planking or outer wall to an inner skeleton or frame structure. A rudder blade is divided into several sections. A first rudder blade section can be a main section of the rudder blade, which in particular has a rudder blade hub for connection to a rudder stock. Another rudder blade section can be designed as a front rudder blade section and comprise a leading edge of the rudder blade. Furthermore, a rudder blade comprises a rear rudder blade section, which has a trailing edge of the rudder blade or a rudder fin that is attached at the end in a hinged manner. The rear rudder blade section can be designed as part of the main section.

[0010] When the rudder blade is arranged on the hull, the front rudder blade section is arranged at the front with respect to the forward direction of travel of the ship, while the rear rudder blade section or the rudder fin is arranged at the rear with respect to the forward direction of travel of the ship when the rudder blade is arranged on the hull. A rudder blade can also have further rudder blade sections, such as an intermediate section, which is preferably arranged between the front rudder blade section and the rear rudder blade section, viewed in the forward direction of travel of the ship, and is preferably arranged below the main section and above a rudder blade sole section. When arranged on the ship, the forward direction of travel corresponds to a longitudinal direction of the rudder blade.

[0011] Particularly in the case of large rudder blades for full-balance or semi-balance rudders, i.e. rudder blades that are larger than rudder blades for small rudders, such as those found on dinghies or sailboats, the manufacture of the rudder blade by planking a skeleton or frame structure is complex. In addition, rudder blades manufactured using conventional methods are very heavy. In addition, the sections of a rudder blade are subject to different strength and stability requirements, which cannot be met using conventional manufacturing processes without compromising the final weight. In addition, full-balance or semi-balance rudders for medium-sized or large vessels in particular must be individually constructed and thus cost-intensive. Another known problem is that the leading edges of rudder blades are difficult to manufacture using conventional welding processes due to varying radii. Description of the invention: task, solution, advantages

[0012] The object of the present invention is to provide a rudder blade that is lighter, simpler and more cost-effective to manufacture, meets the different strength and stability requirements of various rudder blade sections, can be manufactured at least partially by automated means, and facilitates the production of irregular surfaces, particularly the leading edge. Furthermore, the object of the present invention is to provide a segment for a rudder blade or for a device for propulsion improvement, as well as a method for manufacturing a rudder blade or a rudder blade segment, with which the aforementioned advantages are achieved.

[0013] To achieve the object, a rudder blade is proposed, wherein the rudder blade has a modular structure, wherein the rudder blade comprises at least two prefabricated rudder blade segments and is composed of the at least two prefabricated rudder blade segments, wherein the rudder blade has a main section for connection to a rudder stock and a front rudder blade section with a leading edge, wherein the main section is a first rudder blade segment and wherein the front rudder blade section is a second rudder blade segment, wherein the main section consists of a different material and is produced by a different manufacturing process than the front rudder blade section, and wherein the front rudder blade section has bionic structures, wherein the bionic structures are designed to reduce flow resistance.

[0014] Since the rudder blade comprises and is assembled from at least two prefabricated rudder blade segments, the individual rudder blade segments of the at least two rudder blade segments can be manufactured separately or independently before being assembled to form the rudder blade according to the invention. The rudder blade sections, which are therefore more advantageous in terms of their weight and their smaller dimensions compared to the finished rudder blade, can be manufactured using smaller and therefore more cost-effective production lines. The rudder blade segments can also be better adapted to the stability and strength requirements applicable to them. Furthermore, the individual rudder blade segments can be optimized in terms of their weight, for example, by using different manufacturing techniques or different materials.Assembling a rudder blade from prefabricated rudder blade segments also has the advantage that individual rudder blade segments can be manufactured at least partially automatically. Segmenting the rudder blade also allows the use of manufacturing processes that are difficult to manufacture in the prior art, particularly irregular surfaces, such as leading edges, without having to forego the advantages of other manufacturing processes for other rudder blade sections.

[0015] The rudder blade is preferably intended for a rudder of a large ship, for example a container ship, an oil tanker, or a passenger ship. The rudder area of ​​the rudder blade is particularly preferably larger than 50 m², more preferably larger than 70 m², particularly preferably larger than 90 m², and most preferably larger than 100 m².

[0016] More preferably, the rudder blade according to the invention has a weight of more than 50 t, preferably more than 70 t, particularly preferably more than 90 t.

[0017] Preferably, the rudder blade is designed as a rudder blade for a fully suspended or semi-suspended rudder.

[0018] According to the invention, the rudder blade has a main section and a front rudder blade section with a leading edge, and the main section is a first rudder blade segment and the front rudder blade section is a second rudder blade segment.

[0019] In the rudder blade, the main section can be a central rudder blade section, which is particularly designed for connecting a rudder stock or a rudder system. Thus, the central rudder blade section or the main section can have a rudder blade hub for connecting the rudder blade to a rudder stock. The main section can also be referred to as a "main piece" or "central rudder blade section." The term "rudder blade structure connected with solid parts" is also possible for the main section.

[0020] The front rudder blade section comprises the leading edge of the rudder blade and, when arranged on the ship, is located at least partially in front of the main section of the rudder blade with respect to a forward direction of travel. However, the front rudder blade section can also be arranged at least partially below the main section. If the rudder blade is composed of two rudder blade segments, a first rudder blade segment and a second rudder blade segment, the main section is identical to the first rudder blade segment and the front rudder blade section is identical to the second rudder blade segment. More preferably, the main section or the first rudder blade segment can also comprise the rear rudder blade section or the trailing edge of the rear rudder blade section or a rudder fin that is or can be fastened to the rudder blade.

[0021] In an embodiment not encompassed by the invention, the main section and the front rudder blade section do not have to be identical to the first rudder blade section and the second rudder blade section. For example, the main section and / or the front rudder blade section may have multiple rudder blade segments, or a rudder blade segment may be part of both the main section and the front rudder blade section.

[0022] Since different strength and stability requirements must be met for the main section and for the front rudder blade section of a rudder blade, it is particularly advantageous that the main section is a first rudder blade segment and that the front rudder blade section is a second rudder blade segment, wherein the first rudder blade segment is not part of the front rudder blade section and the second rudder blade segment is not part of the main section.

[0023] Thus, both the main section and the front rudder blade section can be freely shaped or constructed according to the applicable strength and stability requirements and, if necessary, manufactured using different manufacturing processes. This enables simple assembly and reduces manufacturing costs, weight, and the required material. Furthermore, the modular design with a first rudder blade segment and a second rudder blade segment enables at least partial automation of the rudder blade production.

[0024] Preferably, it can be provided that the rudder blade has a rear rudder blade section with an end strip, that the rudder blade comprises at least three prefabricated rudder blade segments and is composed of the at least three prefabricated rudder blade segments, wherein the rear rudder blade section comprises or is a third rudder blade segment.

[0025] Furthermore, it can preferably be provided that the rudder blade has an intermediate section, that the rudder blade comprises at least four prefabricated rudder blade segments and is composed of the at least four prefabricated rudder blade segments, wherein the intermediate section comprises or is a fourth rudder blade segment.

[0026] If the main section of the rudder blade does not include the rear rudder blade section and / or the trailing edge, a separate rear rudder blade section may be provided. When arranged on the hull and with respect to the forward direction of travel of the vessel, the front rudder blade section is thus located at least partially in front of the main section, and the main section is located at least partially in front of the rear rudder blade section. The front rudder blade section may also include a rudder blade sole section, which extends below the main section and, if appropriate, below the rear rudder blade section. The rudder blade sole section is preferably aligned approximately perpendicular to the leading edge. "Approximately perpendicular" is to be understood as meaning that the angle between the leading edge and the rudder blade sole section is between 60° and 90°, preferably between 70° and 90°, in particular between 80° and 90°.The angle can also be exactly 90°.

[0027] If an intermediate section is also provided, it can be formed or manufactured from a fourth rudder blade segment. The intermediate section can also be called a "semi-flat piece." The forward rudder blade section can also be called a "curved piece," and the rear rudder blade section can also be called a "flat piece."

[0028] In a roughly schematic side view of the rudder blade, the rudder blade can have the following structure. The front rudder blade section, comprising the leading edge and a rudder blade sole section, is approximately L-shaped. When arranged on the ship and viewed with respect to the forward direction of travel of the ship, the main section is located behind the front rudder blade section and above the rudder blade sole section. Viewed with respect to the forward direction of travel, the rear rudder blade section is arranged behind the main section. The rear rudder blade section is also located above the rudder blade sole section of the front rudder blade section.The intermediate section is located behind the front rudder blade section and in front of the rear rudder blade section in the longitudinal direction of the rudder blade, and below the main section and above the rudder blade sole section of the front rudder blade section in the vertical direction. The L-shaped front rudder blade section, the rear rudder blade section, and the main section enclose the intermediate section.

[0029] In principle, however, more than four rudder blade sections or rudder blade segments can be provided.

[0030] Preferably, the at least two rudder blade segments and / or the rudder blade sections are connected to one another, wherein the connection is made by gluing, welding, positive locking or a combination of these methods. In particular, the second rudder blade segment and / or the front rudder blade section is preferably connected to at least one further rudder blade segment and / or rudder blade section by an adhesive connection or by a combination of an adhesive connection and a positive locking. The positive locking can be achieved by a click connection or by a connection with a profile strip. To connect the at least two rudder blade segments and / or the rudder blade sections, different connection methods can be used for each connection area. For example, the first rudder blade segment orthe main section is connected to the third and / or fourth rudder blade segment, in particular to the rear rudder blade section and / or the intermediate section, by welding, while the second rudder blade segment, in particular the front rudder blade section, is connected to the other rudder blade segments or rudder blade sections by gluing or by gluing with positive locking.

[0031] Advantageously, it can be provided that at least one rudder blade segment of the at least two rudder blade segments comprises a different material and / or consists of a different material and / or is produced by a different manufacturing process than at least one further rudder blade segment of the at least two rudder blade segments, wherein it is provided according to the invention that the main section consists of a different material and is produced by a different manufacturing process than the front rudder blade section.

[0032] By using different materials and manufacturing processes for the individual rudder blade segments, the specific strength and stability requirements of the individual rudder blade sections or segments can be met. Furthermore, automation of the rudder blade manufacturing process can be achieved.

[0033] Preferably, the front rudder blade section, in particular the second rudder blade segment, has a rudder blade sole section, and / or the front rudder blade section has a propulsion bulb.

[0034] The front rudder blade section, in particular the second rudder blade segment, can have a rudder blade sole section and be approximately L-shaped in a side view, wherein the rudder blade sole section is directed rearward with respect to the forward direction of travel of the vessel and is arranged in the lower region of the leading edge of the front rudder blade section. In particular, the leading edge transitions into the rudder blade sole section in a curve over a radius.

[0035] It is preferably provided that the main section, in particular the first rudder blade segment, and / or the front rudder blade section, in particular the second rudder blade segment, and / or the rear rudder blade section, in particular the third rudder blade segment, and / or intermediate section, in particular the fourth rudder blade segment, comprises a curved outer wall.

[0036] It can further preferably be provided that the rear rudder blade section, in particular the third rudder blade segment, comprises a flat outer wall.

[0037] In particular, the rear rudder blade section, or the third rudder blade segment, which includes the trailing edge, can have a flat outer wall. Thus, the rear rudder blade section can comprise two flat side walls that converge towards the trailing edge in an approximately V-shaped manner when viewed from above. The trailing edge runs along the contact line of the two flat side walls. If the rear rudder blade section is prefabricated as a third rudder blade segment, this enables automation of the rudder blade production, since the flat side walls are particularly suitable for automated production due to the lack of curved outer surfaces, which are difficult to produce.

[0038] Nevertheless, it is also possible that the outer wall of the rear rudder blade section, in particular of the third rudder blade segment, is at least partially curved or has a kink or is kinked.

[0039] Advantageously, at least one rudder blade segment, in particular the first rudder blade segment, is a welded construction with transverse frames and longitudinal frames.

[0040] For example, the main section can be a welded construction with transverse and longitudinal frames. Accordingly, the main section, or the first rudder blade segment, can be manufactured using a known manufacturing process by providing a skeleton or frame structure consisting of transverse and longitudinal frames and by planking the frame or skeleton structure with an outer wall. Such a manufacturing process is particularly suitable for meeting the stability and strength requirements imposed on the main section. The main section, or the first rudder blade segment, preferably has a rudder blade hub for connecting the rudder blade to a rudder stock. Accordingly, a large portion of the rudder forces are dissipated via the main section.However, in contrast to rudders known from the prior art, preferably only the main section or the first rudder blade segment is designed as a welded construction with transverse and longitudinal frames, while the second rudder blade segment and optionally the further rudder blade segments are manufactured using other manufacturing processes.

[0041] Preferably, at least one rudder blade segment, in particular the second rudder blade segment, can be manufactured using a milling process. It can also be provided that at least one rudder blade segment, in particular the second rudder blade segment, is formed as a fiber composite part or a laminate component.

[0042] In a particularly preferred embodiment, it is provided that at least one rudder blade segment, in particular the second rudder blade segment, is manufactured using a generative manufacturing process and / or an additive manufacturing process, in particular using a 3D printing process.

[0043] Generative manufacturing processes or additive manufacturing processes also include processes referred to as rapid prototyping processes. In generative and additive manufacturing processes, production is preferably carried out directly on the basis of computer-internal data models and preferably from amorphous liquids, gels, pastes, powders or form-neutral ribbon-shaped, wire-shaped or sheet-shaped materials, using chemical and / or physical processes. Such generative or additive processes are also referred to as 3D printing processes. A wide variety of designs for generative, additive or 3D printing processes are known in the prior art, for example and in a non-exhaustive list: laser melting, electron beam melting, cladding, stereolithography, laminated object modeling, 3D screen printing and light-controlled electrophoretic deposition or fused deposition modeling.

[0044] By using a generative or additive manufacturing process for at least one rudder blade segment, in particular for the second rudder blade segment, and further in particular for the front rudder blade section, rapid, automated, and cost-effective production of a rudder blade segment, in particular the second rudder blade segment, can be enabled. Furthermore, rudder blade sections can be shaped relatively freely. A further advantage of using a generative, additive, or 3D printing process is that surfaces that are relatively difficult to produce in the prior art, such as the surface of a leading edge or irregular surfaces, can be manufactured more easily and cost-effectively.

[0045] In a preferred embodiment, the rudder blade comprises a first rudder blade segment designed as a main section and a second rudder blade segment designed as a front rudder blade section, wherein the second rudder blade segment or the front rudder blade section comprises a rudder blade sole section and is approximately L-shaped. The main section or the first rudder blade segment is arranged in the open angle of the L-shaped front rudder blade section or the second rudder blade segment and is connected to it to form a rudder blade. The main section can be manufactured using a known manufacturing process as a welded construction with transverse and longitudinal frames, while the front rudder blade section, which is in particular L-shaped, is manufactured using a generative, additive or 3D printing process.The rudder blade may also comprise, as described above, further rudder blade sections, such as a rear rudder blade section or an intermediate section, which also comprise or are rudder blade segments.

[0046] In a further advantageous embodiment, it can be provided that at least one rudder blade segment, in particular the third rudder blade segment, is a lightweight construction element.

[0047] Advantageously, the rear rudder blade section can be the third rudder blade segment. Accordingly, the rear rudder blade section is designed as a lightweight construction element. Furthermore, the rear rudder blade section or the third rudder blade segment is preferably arranged behind the front rudder blade section and / or behind the main section, as viewed in the forward direction of travel of a ship, and can also be arranged above a rudder blade sole section of the front, preferably L-shaped, rudder blade section.

[0048] The rear rudder blade section, or the third rudder blade segment, is particularly suitable for being designed as a lightweight construction element.

[0049] Preferably, the rudder blade segment designed as a lightweight construction element, in particular the third rudder blade segment, can be a T-honeycomb construction element, a panel construction element or a solid steel honeycomb construction element.

[0050] Instead of frames of a frame structure, in particular instead of horizontally aligned longitudinal frames, a T-honeycomb component has L- or T-profiles which are formed into approximately circular or polygonal or N-shaped, in particular octagonal, structural elements which are closed in a circumferential direction.

[0051] The opposite sides of the polygon or octagon do not necessarily have to be the same length, and the angles between the sides of the polygon do not all have to be the same either. The flanges of the T- or L-profiles form the outer surface of the structural elements. The webs of the T- or L-profiles are directed towards an inner area enclosed by the flanges and border an opening in the interior of the respective structural element. The side walls of the rudder blade segment, in particular the third rudder blade segment, are arranged on two opposite areas or sides of the structural element formed by the flanges.

[0052] If the rear rudder blade section is the third rudder blade segment and is designed as a T-shaped honeycomb element, the side walls, which are particularly flat, are arranged at an angle to a trailing edge and are connected or welded to one another along the trailing edge. Instead of the familiar frame structure of transverse and longitudinal frames, a framework of L- or T-profiles formed into structural elements extends between the approximately V-shaped side walls of the rear rudder blade section.

[0053] If the rudder blade segment, in particular the third rudder blade segment, further in particular the rear rudder blade section, is a panel component, it is manufactured in particular by the following manufacturing steps: Providing a first panel plate, arranging a first number of reinforcement bodies on the first panel plate, fastening the first number of reinforcement bodies on the first panel plate to produce a first panel, providing a second panel plate, arranging a second number of reinforcement bodies on the second panel plate, fastening the second number of reinforcement bodies on the second panel plate to produce a second panel, arranging the first panel and the second panel such that the first panel plate and the second panel plate form an outer wall of the rudder blade or rudder blade segment to be produced and that the first number of reinforcement bodies and the second number of reinforcement bodies are directed into an interior of the rudder blade or rudder blade segment to be produced, connecting the first panel and the second panel.

[0054] Such a panel component is the subject of the applicant's European patent application "Method for producing a rudder blade or a rudder blade segment, rudder blade and rudder blade segment" of the same filing date as the present patent application.

[0055] In the third rudder blade segment, which is designed as a panel component, the reinforcing bodies function as a frame structure consisting of longitudinal and transverse frames. The reinforcing bodies thus preferably serve to reinforce or increase the stability or strength of the rudder blade segment. The reinforcing bodies can preferably be ribs and / or plates and / or frames, in particular transverse and / or longitudinal frames, and / or sections of frames, in particular sections of transverse and / or longitudinal frames.

[0056] The panels can further preferably be manufactured using a welding process, in particular a robot welding process.

[0057] The individual panels can be manufactured on a panel production line and then assembled into a rear rudder blade section or a third rudder blade segment. This further automates the manufacturing process and reduces costs.

[0058] If the rudder blade segment, in particular the third rudder blade segment, is designed as a solid steel honeycomb component, a honeycomb structure of adjacent honeycombs is located between the side walls of the third rudder blade segment. The honeycomb structure can have the structure of a bee's honeycomb. In particular, the longitudinal axes of the honeycombs extend between the side walls. The honeycombs are aligned approximately vertically with respect to a center plane of the rudder blade segment, which, when arranged on the ship, is oriented vertically and in a longitudinal direction corresponding to the forward direction of the ship.

[0059] Preferably, the leading edge of the front rudder blade section, in particular of the second rudder blade segment, is a twisted or offset leading edge.

[0060] The rudder blade can, in particular, be designed as a twisted rudder blade, which has an upper rudder blade region and a lower rudder blade region. The upper rudder blade region and the lower rudder blade region each have a profile with a suction side and a pressure side. The profile shape is thus roughly similar to the profile of an aircraft wing. The profile in the upper rudder blade region is mirror-inverted to the profile in the lower rudder blade region, particularly with respect to the center plane of the rudder blade.In a twisted rudder, the leading edge of the front rudder blade section is therefore not continuous, but the section of the leading edge in the upper rudder blade area, which lies above the propeller hub of the ship's propeller when the rudder blade is mounted on the ship, is offset from the section of the leading edge in the lower rudder blade area, which lies below the propeller hub of the ship's propeller when mounted on the ship, in such a way that the upper section of the leading edge is directed or twisted or offset to starboard, while the lower section of the leading edge is directed or twisted or offset to port. Depending on the direction of rotation of the propeller, the upper section of the leading edge can also be directed or twisted or offset to port and the lower section to starboard.In other words, if the suction side of the upper rudder blade area is on the starboard side, the suction side of the lower rudder blade area is on the port side, or vice versa. Similarly, the pressure side of the upper rudder blade area is on the port side and the pressure side of the lower rudder blade area is on the starboard side, or vice versa.

[0061] According to the invention, it is provided that the front rudder blade section, in particular the second rudder blade segment, has bionic structures, in particular a surface with bionic structures.

[0062] A bionic structure is a structure that occurs in nature, for example in the animal or plant kingdom, which is transferred to technical systems in order to achieve a specific purpose or goal in a technical context.

[0063] It is advantageous that the bionic structure is manufactured using a generative manufacturing process and / or an additive manufacturing process, in particular using a 3D printing process.

[0064] Particularly preferably, the surface of the leading edge of the front rudder blade section, or of the second rudder blade segment, is provided with a bionic structure. It is particularly advantageous if the rudder blade segment, in particular the second rudder blade segment, furthermore in particular the front rudder blade section, comprising the bionic structure, is manufactured using a generative, additive or 3D printing process. Such manufacturing processes are particularly suitable for the production of bionic structures. In particular, with manufacturing processes known from the prior art, it is not cost-effective and, moreover, relatively difficult to produce irregular surfaces, for example with varying radii or with bionic structures.The preferred combination of a generative or additive or 3D printing process with the provision of bionic surface structures, in particular in the case of a leading edge of a front rudder blade section or a second rudder blade segment, thus achieves the advantage of cost-effective provision of bionic structures.

[0065] However, the surface with bionic structures can also be created by a material-removing process, such as a milling process, or by a casting process. Furthermore, it is also possible to produce the bionic structure using conventional welding processes. However, production of the bionic structure, in particular the bionic structure of the leading edge of the second rudder blade segment, is preferred using an additive, generative, or 3D printing process.

[0066] In addition, it is of course also possible for other rudder blade segments to have bionic surface structures.

[0067] Further advantageously, the bionic structure is designed to delay a flow stall. Furthermore, it can be provided that the bionic structure is a sharkskin structure and / or that the bionic structure is a fin structure, in particular a whale fin structure.

[0068] In particular, bionic structures, such as a shark skin structure or a fin structure, are particularly suitable for reducing the flow resistance of the rudder blade and / or delaying a stall.

[0069] In addition, it may be preferred that at least one of the at least two rudder blade segments, preferably the first rudder blade segment and / or the second rudder blade segment and / or the third rudder blade segment and / or the fourth rudder blade segment, comprises at least two sub-segments.

[0070] The sub-segments can also be prefabricated, and the at least one rudder blade segment of the at least two rudder blade segments is composed of the at least two sub-segments. The rudder blade segment composed of at least two sub-segments is then assembled with further rudder blade segments, which can also comprise sub-segments or be composed of them, to form a rudder blade. For example, the main section of the rudder blade, in particular the first rudder blade segment, can be composed of two sub-segments. Preferably, a first sub-segment of the main section or of the first rudder blade segment is arranged above the propeller hub of the ship's propeller when arranged on the ship, and a second sub-segment of the first rudder blade segment is arranged below the propeller hub of the propeller when arranged on the ship.This means that the first sub-segment is also located above the second sub-segment when arranged on the ship.

[0071] Particularly in the case of twisted rudders, a first rudder blade segment, or main section, composed of at least two sub-segments is advantageous. The first sub-segment is then preferably arranged in the upper rudder blade region, which preferably comprises a leading edge twisted, directed, or offset to port or starboard, whereas the second sub-segment is arranged in the lower rudder blade region, which comprises a leading edge twisted, directed, or offset in the opposite direction to starboard or port. By forming the at least one rudder blade segment, in particular the first rudder blade segment or the main section, from at least two sub-segments, manufacturing costs can be reduced and production of the rudder blade can be simplified. In addition, it is easily possible to form an upper rudder blade region and a lower rudder blade region for a twisted rudder.

[0072] However, additional rudder blade segments, such as the second, third, fourth, or further rudder blade segments, may also comprise at least two subsegments. For example, the rear rudder blade section, the front rudder blade section, or the intermediate section may also be composed of at least two subsegments.

[0073] The front rudder blade section, in particular the second rudder blade segment, which is preferably approximately L-shaped and has a rudder blade sole section, can particularly preferably comprise at least two subsegments or be composed of at least two subsegments. Thus, it is particularly advantageous for the rudder blade sole section to be composed of several subsegments, in particular manufactured using an additive, generative, or 3D printing process. A further subsegment can be designed as a propulsion bulb.

[0074] It is also possible for the front rudder blade section, in particular the second rudder blade segment, to comprise sub-segments, wherein a first sub-segment comprises an upper section of the leading edge. The upper section of the leading edge is arranged above the propeller hub when arranged on the ship. The upper section of the leading edge is, for example, offset, twisted or directed to starboard. A second sub-segment can comprise a lower section of the leading edge. The lower section of the leading edge is arranged below the propeller hub when arranged on the ship. The lower section of the leading edge is then, for example, offset, twisted or directed to port.

[0075] It can further advantageously be provided that the first rudder blade segment has a first sub-segment and a second sub-segment and is composed of the first sub-segment and the second sub-segment, wherein a connecting body, in particular a stabilizing plate, is preferably arranged between the first sub-segment and the second sub-segment.

[0076] A connecting body arranged between the first subsegment and the second subsegment of the first rudder blade segment serves to connect the first and second subsegments and also increases the stability of the first rudder blade segment, in particular of the main section. The provision of a connecting body such as a stabilizing plate is particularly advantageous in a twisted rudder, in which the first subsegment and the second subsegment have a substantially mirror-inverted profile shape.

[0077] A solution to the problem underlying the invention, which is not encompassed by the invention, consists in the provision of a rudder blade segment of a rudder blade described above.

[0078] A further solution to the problem not encompassed by the invention consists in the provision of a rudder blade segment for a rudder blade as described above, wherein the rudder blade segment is a front rudder blade section, wherein the rudder blade segment comprises a leading edge, wherein the rudder blade segment is produced using a generative manufacturing method and / or an additive manufacturing method, in particular using a 3D printing method, and wherein the rudder blade segment has bionic structures, wherein the bionic structures are preferably designed to reduce flow resistance.

[0079] The segment may be part of a complete rudder blade or a complete propulsion enhancement device. However, the segment may also be designed as a complete rudder blade or a complete propulsion enhancement device, and in particular, may be identical to a complete rudder blade or a complete propulsion enhancement device.

[0080] Preferably, however, the segment is a front rudder blade section for a previously described rudder in modular design.

[0081] Furthermore, the segment can also be a segment for a device for improving propulsion. Such devices are designed, for example, as pre-nozzles, Kort nozzles, Mewis-Duct nozzles or propeller nozzles. Devices for improving propulsion properties have leading edges just like rudder blades. Furthermore, the segment can also be designed as a fin or stabilizing fin. Fins are used in particular in nozzles such as Kort nozzles, Mewis-Duct nozzles, pre-nozzles or propeller nozzles and are usually arranged inside the nozzle. However, the fins can also be arranged on the outside of the nozzle. Fins are usually arranged in a radial direction from a central axis towards a nozzle casing or from an outer wall of the nozzle casing of the nozzle outwards. Furthermore, fins have a profile shape that is suitable for influencing water flow.In particular, fins are equipped with a suction side and a pressure side. Fins arranged behind a propeller can smooth out turbulence in the downstream flow of a propeller. This allows energy to be recovered or propulsion characteristics to be improved. Fins can also be arranged in front of the propeller, particularly in a pre-nozzle. The fins create a pre-swirl in the water flowing towards the propeller, which can also save energy and improve propulsion characteristics. Fins or stabilizing fins also have a leading edge.

[0082] It is particularly advantageous if the segment is designed as a rudder blade segment for a front rudder blade section and has a leading edge. Such rudder blade segments are difficult and costly to manufacture using known methods. In particular, it is difficult to produce a leading edge with varying radii using known welding methods. By manufacturing the rudder blade segment using an additive, generative, or 3D printing process, a front rudder blade section with a leading edge, in particular with varying radii, can be manufactured simply and cost-effectively and freely shaped regardless of strength considerations.

[0083] If the segment is designed as a front nozzle section, the leading edge is essentially circularly curved.

[0084] It can further advantageously be provided that the segment is a rudder blade segment and comprises a propulsion bulb.

[0085] The propulsion bulb can be prefabricated as a sub-segment, for example, using a 3D printing process, and assembled with another, likewise prefabricated sub-segment to form the rudder blade segment, in particular for a previously described rudder blade. The rudder blade segment produced in this way advantageously forms a front rudder blade section of a previously described rudder blade section.

[0086] If the segment is a front rudder blade section for a previously described rudder in modular design, the embodiments explained below can also be transferred in a corresponding manner to the front rudder blade section, or the second rudder blade segment, of the previously described rudder blade.

[0087] It is then intended that the segment has bionic structures, in particular a surface with bionic structures.

[0088] The bionic structures are designed to reduce flow resistance, wherein the bionic structure is preferably a shark skin structure and / or wherein the bionic structure is a fin structure, in particular a whale fin structure.

[0089] Such bionic structures are particularly suitable for reducing flow resistance.

[0090] Particularly preferably, the bionic structure is arranged on a surface of a leading edge.

[0091] Furthermore, it may be preferred that the bionic structures are produced in a generative manufacturing process and / or an additive manufacturing process, in particular in a 3D printing process, and / or by a material-removing process, in particular a milling process, and / or by a casting process.

[0092] It is particularly advantageous if a generative, additive, or 3D printing process is used to manufacture the bionic structures of the segment. The surface of the segment, particularly the leading edge, preferably has bionic structures. The segment is manufactured using a 3D printing process or an additive or generative manufacturing process, whereby the bionic structures, particularly on the leading edge, are also manufactured during the production of the segment using the additive, generative, or 3D printing process.

[0093] With further advantage, the segment has at least two sub-segments and / or the segment is composed of at least two sub-segments.

[0094] By assembling sub-segments, in particular prefabricated ones, to form a segment for a rudder blade or for a propulsion improvement device, the manufacture of such segments can be further simplified and the manufacturing costs reduced.

[0095] Particularly preferably, a segment having at least two subsegments or composed of at least two subsegments is designed as a second rudder blade segment for a previously described rudder blade. This second rudder blade segment can be designed as a front rudder blade section for a previously described modular rudder blade and can have a first upper region with a leading edge and a lower second region oriented approximately perpendicular to the first region. The second region is advantageously a rudder blade sole section and merges into the first region at a radius and is oriented approximately perpendicular to the first region, so that the rudder blade segment is approximately L-shaped."Approximately perpendicular" is to be understood as meaning that the angle between the first upper area with the leading edge and the second lower area, the rudder blade sole section, is between 60° and 90°, preferably between 70° and 90°, in particular between 80° and 90°. The angle can also be exactly 90°.

[0096] If the segment is designed as a nozzle segment for a nozzle, the subsegments can have a leading edge or sections of a leading edge. A subsegment of the nozzle segment can correspond to a sixteenth, an eighth, a quarter, a half, or even the entire circumference of the nozzle or an inlet opening of the nozzle.

[0097] It is particularly advantageous if the sub-segments are connected to each other, in particular with a click closure system, by gluing, screwing or welding.

[0098] If the sub-segments are manufactured using a generative, additive or 3D printing process, they can particularly advantageously have a click-lock system and can be connected to one another to form a rudder blade segment or a nozzle segment by means of the click-lock system.

[0099] Connecting the sub-segments by gluing and / or screwing is also particularly advantageous for sub-segments manufactured using an additive, generative or 3D printing process.

[0100] Furthermore, it can be provided that the segment is designed as a front rudder blade section and has a rudder blade sole section.

[0101] It is particularly preferred that the rudder blade sole section is composed of sub-segments.

[0102] The sub-segments of the rudder blade sole section can be joined together using a click-lock system, by gluing, screwing or welding.

[0103] In an advantageous embodiment, it is provided that the sub-segments are approximately U-shaped and have a recess or groove running in a longitudinal direction for connection to another segment.

[0104] Subsegments, which are approximately U-shaped, can be particularly advantageously assembled into a rudder blade sole section using a snap-lock system, by gluing, screwing, or welding. The recess or groove preferably serves to accommodate another rudder blade segment, such as a previously described main section or a previously described intermediate section.

[0105] For this purpose, the corresponding rudder blade segment has a rib, flange, or tongue complementary to the recess or groove, which can engage in the recess or groove and, in particular, leads to a lateral positive fit. The rudder blade segment, which is assembled from subsegments and is designed for a front rudder blade section, can be assembled with the other rudder blade segments to form a rudder blade with a modular structure. The connection between the other rudder blade segments and the rudder blade segment can additionally or alternatively be made by means of a click-lock system, by gluing, welding, or screwing.

[0106] It can further advantageously be provided that the sub-segments have a first end face and a second end face, wherein connecting means are arranged in the first end face and the second end face for connecting two sub-segments at their end faces.

[0107] In other words, the sub-segments can be joined together with their end faces in such a way that the connecting means of the first end face of the first sub-segment and the connecting means of the second end face of the second sub-segment connect or are connected to one another, so that the sub-segments can be assembled to form its segment, in particular to form a rudder blade segment.

[0108] Furthermore, it can be provided that the recess or groove does not run centrally in the sub-segment.

[0109] A further solution to the problem underlying the invention lies in the provision of a method for producing a rudder blade as described above in a modular design comprising the steps: Producing a first rudder blade segment, Producing a second rudder blade segment, Joining together at least the first rudder blade segment and the second rudder blade segment, wherein the first rudder blade segment is a main section of a rudder blade, and wherein the second rudder blade segment is a front rudder blade section, wherein the main section consists of a different material and is manufactured by a different manufacturing process than the front rudder blade section, and wherein the first rudder blade segment is manufactured in a welding process by planking a skeletal structure made of transverse frames and longitudinal frames, and wherein the second rudder blade segment is manufactured using a generative manufacturing process and / or an additive manufacturing process, and wherein the second rudder blade segment has bionic structures, wherein the bionic structures are designed to reduce flow resistance.

[0110] Furthermore, it can be provided that, to form a rudder blade in a modular design, further rudder blade segments, in particular a third and / or a fourth rudder blade segment, are joined to the first rudder blade segment and the second rudder blade segment. The rudder blade segments can be designed in accordance with the previously described rudder blade segments, in particular the previously described rudder blade segments for a modular rudder blade.

[0111] It can further preferably be provided that a third rudder blade segment is a rear rudder blade section and / or that a fourth rudder blade segment is an intermediate section of a rudder blade to be manufactured.

[0112] It can further preferably be provided that the generative manufacturing process and / or the additive manufacturing process is a 3D printing process. Short description of the characters

[0113] The present invention is explained in more detail below with reference to the figures. Fig. 1 is a perspective view of a rudder blade with a modular structure, Fig. 2 is an exploded view of a rudder blade with a modular structure, Fig. 3 is a rudder blade segment designed as a front rudder blade section, Fig. 4 is a structured surface with bionic structures, Fig. 5 is a rudder blade segment designed as a main section with a first sub-segment and a second sub-segment, Fig. 6 is a perspective view of a sub-segment for a rudder blade sole section, Fig. 7a is a front view of a sub-segment for a rudder blade sole section, Fig. 7b is a rear view of a sub-segment for a rudder blade sole section, Fig. 8a is a top view of a sub-segment for a rudder blade sole section, and Fig. 8b is a side view of a sub-segment for a rudder blade sole section. Detailed description of the characters

[0114] Fig. 1shows a perspective view of a rudder blade 100 with a modular structure. The rudder blade 100 has prefabricated rudder blade segments 10, 11, 12, 13 and is composed of the rudder blade segments 10, 11, 12, 13. A first rudder blade segment 10 is designed as a main section 14. A second rudder blade segment 11 is designed as a front rudder blade section 15. A third rudder blade segment is designed as a rear rudder blade section 16. A fourth rudder blade segment 13 is designed as an intermediate section 17. The front rudder blade section 15 comprises a leading edge 18 and a propulsion bulb 19. The second rudder blade segment 11, or the front rudder blade section 15, is approximately L-shaped, with a rudder blade sole section 21 adjoining the lower region 20.The rudder blade sole section 21 is aligned approximately at a right angle to the section of the second rudder blade segment 11 where the leading edge 18 is arranged, and merges into this section via a radius 22. The rudder blade sole section 21 can be formed integrally with the second rudder blade segment 11, which represents the front rudder blade section 15. However, it is also possible for the rudder blade sole section 21 to be a separate rudder blade segment. The third rudder blade segment 12 has a trailing edge 23. The outer walls 24 of the rear rudder blade section 16, or the third rudder blade section 12, are flat. The fourth rudder blade segment, formed as an intermediate section 17 and also referred to as a "semi-flat piece," has substantially slightly curved outer walls 25.In the illustrated arrangement, the first rudder blade segment 10, the second rudder blade segment 11, and the third rudder blade segment 12 enclose the intermediate section 17 and the fourth rudder blade segment 13, respectively. The illustrated rudder 100 is a twisted rudder. This means that the upper section 26a of the leading edge 18 is offset from a lower section 26b of the leading edge 18, so that the upper section 26a is offset toward port while the lower section 26b is offset toward starboard.

[0115] Fig. 2shows an exploded view of the rudder 100 with a modular design. The second rudder blade segment 11, which is designed as the front rudder blade section 15, comprises the leading edge 18, the propulsion bulb 19, and the rudder blade sole section 21. The first rudder blade segment 10, designed as the main section 14, is composed of a first sub-segment 27 and a second sub-segment 28. The first sub-segment 27 and the second sub-segment 28 are connected to one another via a connecting body 30 designed as a stabilizing plate 29. A longitudinal frame 32 is visible on an underside 31 of the second sub-segment 28 of the main section 14.The main section 14 or the first rudder blade segment 10 composed of the first sub-segment 27 and the second sub-segment 28 is manufactured in a conventional manufacturing process by planking a skeleton structure 33 formed from longitudinal frames 32 and transverse frames with an outer wall 34.

[0116] The second rudder blade segment 11, which forms the front rudder blade section 15, is manufactured using an additive or generative manufacturing process, in particular a 3D printing process.

[0117] The third rudder blade segment 12, designed as a rear rudder blade section 16, has a solid steel honeycomb structural element 36 in an interior space 35, so that the third rudder blade segment 12 is designed as a lightweight structural element 37. The fourth rudder blade segment 13, designed as an intermediate section 17, can be manufactured using a conventional manufacturing process by planking a skeleton structure, using a 3D printing process, or using other methods.

[0118] Due to the different manufacturing processes, the materials of the rudder blade segments 10, 11, 12, and 13 also vary. For example, the second rudder blade segment 11, manufactured using a 3D printing process, can be made of plastic or metal. The main section 14, manufactured using a known manufacturing process, is made of steel. The rear rudder blade section 16 can also be manufactured using a conventional or known manufacturing process. However, it is also possible for the rear rudder blade section 16 to be made of or comprise a plastic.

[0119] Fig. 3 shows the second rudder blade segment 11, designed as the front rudder blade section 15, in a perspective view. In the Fig. 3In the embodiment shown, the second rudder blade segment 11 has a structured surface 39. In particular, the leading edge 18 is provided with the structured surface 39. The structured surface 39 has bionic structures 40. The bionic structures 40 can be designed, for example, as a sharkskin structure 41.

[0120] In the detailed view Fig. 4 A section of the structured surface 39 of the leading edge 18 is shown. The bionic structure 40, comprising a shark skin structure 41, has several elevations 42.

[0121] The structured surface 39 or the bionic structure 40 of the leading edge 18 of the second rudder blade segment 11 is advantageously produced simultaneously in the same manufacturing step as the second rudder blade segment 11 using a generative, additive, or 3D printing process. The bionic structures 40 therefore do not have to be subsequently machined from the second rudder blade segment 11, for example, by means of a milling process.

[0122] Fig. 5 shows the main section 14 in a perspective view. The main section 14 is composed of a first sub-segment 27 and a second sub-segment 28, which are connected to each other via a stabilizing plate 29. Arranged inside the main section 14 is a skeleton structure 33 consisting of longitudinal frames 32 and transverse frames 43, which is provided with an outer wall 34.

[0123] Returning to Fig. 3It can be seen that the rudder blade sole section 21 of the second rudder blade segment 11 is also composed of several sub-segments 44. A sub-segment 44 of the rudder blade sole section 21 is shown in a perspective view in Fig. 6 The sub-segment 44 of the rudder blade sole section 21 is approximately U-shaped and has a recess or groove 45 extending in a longitudinal direction 46 of the sub-segment 44. The groove 45 is not arranged centrally, but rather slightly offset within the sub-segment 44. A first end face 47 of the sub-segment 44 has connecting means 49 configured as receiving openings 48.

[0124] In the Fig. 7a and 7b the subsegment 44 is shown in a front view ( Fig. 7a ) and in a rear view ( Fig. 7b). The front view shows a second end face 50 of the sub-segment 44. Connecting means 52, also designed as receiving openings 51, are located in the second end face 50. Fig. 7b In the rear view shown, the connecting means 49 are again shown in the first end face 47.

[0125] Fig. 8a and 8b show a supervision ( Fig. 8a ) and a side view ( Fig. 8b) onto the sub-segment 44. The non-centrally arranged groove 45 in an upper side 53 of the sub-segment 44 is clearly visible. A plurality of sub-segments 44 can be arranged such that a first end face 47 of a first sub-segment 44 comes into contact with a second end face 50 of a second sub-segment 44. Snap-in hooks or click-in connecting elements (not shown) or screws, if necessary, can then be guided into the receiving openings 48, 51, and thus a plurality of sub-segments 44 can be connected to one another to form a rudder blade sole section 21.

[0126] The sub-segment 44 is also manufactured using a 3D printing process as part of the second rudder blade segment 11. The material is preferably PET-G or ABS. In the top view in Fig. 8aIt can also be seen that the course of a first side 54 is more curved than the course of a second side 55 opposite the first side 54. The different course corresponds to the different course of the sides of the rudder blade 100, which is designed as a twisted rudder and thus has a pressure side 56 and a suction side 57. List of reference symbols

[0127] 100Rudder blade 10First rudder blade segment 11Second rudder blade segment 12Third rudder blade segment 13Fourth rudder blade segment 14Main section 15Forward rudder blade section 16Rear rudder blade section 17Intermediate section 18Leading edge 19Propulsion bulb 20Lower section 21Rudder blade sole section 22Radius 23Trailing edge 24Outer wall 25Outer wall 26aUpper section 26bLower section 27First sub-segment 28Second sub-segment 29Stabilization plate 30Connecting body 31Underside 32Longitudinal frame 33Skeleton structure 34Outer wall 35Interior 36Honeycomb element 37Lightweight element 38Panel 39Structured surface 40Bionic structure 41Sharkskin structure 42Elevation 43Cross-rib 44Sub-segment 45Groove 46Longitudinal direction 47First end face 48Receiving opening 49Fasteners 50Second end face 51Receiving opening 52Connecting element 53Top side 54First side 55Second side 56Pressure side 57Suction side

Claims

1. Rudder blade (100) characterized by a modular structure, wherein the rudder blade comprises at least two prefabricated rudder blade segments (10, 11, 12, 13) and is assembled from the at least two prefabricated rudder blade segments (10, 11, 12, 13), wherein the rudder blade has a main section (14) for connection to a rudder stock and a front rudder blade section (15) with a leading edge (18), wherein the main section (14) is a first rudder blade segment (10) and wherein the front rudder blade section (15) is a second rudder blade segment (11), wherein the main section (14) consists of a different material and is produced by a different production method than the front rudder blade section (15), characterized in that the front rudder blade section (15) has a surface with bionic structures (40), wherein the bionic structures (40) are configured for reducing a flow resistance.

2. Rudder blade (100) according to claim 1, wherein the rudder blade (100) has a rear rudder blade section (16) with an end strip (23), wherein the rudder blade comprises at least three prefabricated rudder blade segments (10, 11, 12, 13) and is assembled of the at least three prefabricated rudder blade segments (10, 11, 12, 13), wherein the rear rudder blade section (16) comprises or is a third rudder blade segment (12), and / or wherein the rudder blade has an intermediate section (17), wherein the rudder blade comprises at least four prefabricated rudder blade segments (10, 11, 12, 13) and is assembled of the at least four prefabricated rudder blade segments (10, 11, 12, 13), wherein the intermediate section (17) comprises or is a fourth rudder blade segment (13).

3. Rudder blade (100) according to claim 1 or 2, characterized in that at least one rudder blade segment (10, 11, 12, 13), in particular the first rudder blade segment (10), is a welded construction with transverse frames (43) and longitudinal frames (32), and / or in that at least one rudder blade segment (10, 11, 12, 13), in particular the second rudder blade segment (11), is produced with a generative production method and / or an additive production method, in particular with a 3D printing method.

4. Rudder blade (100) according to one of the preceding claims, characterized in that the bionic structure (40) is a sharkskin structure (41) and / or in that the bionic structure (40) is a fin structure, in particular a whale fin structure.

5. Rudder blade (100) according to one of the preceding claims, characterized in that at least one of the at least two rudder blade segments (10, 11, 12, 13), preferably the first rudder blade segment (10) and / or the second rudder blade segment (11) and / or the third rudder blade segment (12) and / or the fourth rudder blade segment (13), comprises at least two subsegments (27, 28, 44), wherein preferably the first rudder blade segment (10) has a first sub-segment (27) and a second sub-segment (28) and is assembled of the first sub-segment (27) and the second sub-segment (28), wherein particularly preferably a connecting body (30), in particular a stabilizing plate (29), is arranged between the first sub-segment (27) and the second sub-segment (28).

6. Rudder blade (100) according to one of the preceding claims, characterized in that the bionic structures (40) are produced in a generative production method and / or an additive production method, in particular in a 3D printing method, and or by a material-removing method, in particular a milling method, and / or by a casting method.

7. Rudder blade (100) according to one of the preceding claims, characterized in that the front rudder blade section (15) has a rudder blade sole section (21).

8. Rudder blade (100) according to claim 7, in that the rudder blade sole section (21) is assembled of sub-segments (44), wherein the sub-segments (44) are preferably formed approximately U-shaped and have a recess or groove (45) running in a longitudinal direction (46) for connection to a further rudder blade segment, and / or wherein the sub-segments (44) have a first end face (47) and a second end face (50), wherein connecting means (49, 52) are arranged in the first end face (47) and the second end face (50) for connecting two sub-segments (44) each at their end faces (47, 50).

9. Method for producing a rudder blade (100) according to one of the preceding claims in modular construction, comprising the steps of: - Making a first rudder blade segment (10), - Making a second rudder blade segment (11) - Assembling at least the first rudder blade segment (10) and the second rudder blade segment (11), wherein the first rudder blade segment (10) is a main section (14) of a rudder blade (100), and wherein the second rudder blade segment (11) is a front rudder blade section (15), wherein the main section (14) consists of a different material and is produced with a different production method than the front rudder blade section (15), and wherein the first rudder blade segment (10) is produced in a welding method by planking a skeleton structure (33) of transverse frames (43) and longitudinal frames (32), and wherein the second rudder blade segment (11) is produced with a generative production method and / or an additive production method, characterized in that the second rudder blade segment (11) has bionic structures (40), wherein the bionic structures (40) are configured for reducing a flow resistance.

10. Method according to claim 9, characterized in that the generative production method and / or the additive production method is a 3D printing method.