Device and method for measuring resistance reduction effect of water tunnel of revolving body

Abstract

The invention relates to the technical field of rotary body resistance reduction measurement, and discloses a rotary body water tunnel resistance reduction effect measuring device and method.The rotary body water tunnel resistance reduction effect measuring device comprises a rotary body model, a resistance reduction experiment shell, a balance assembly and a supporting assembly.The rotary body model comprises a model bow, a model cabin and a model stern which are sequentially arranged; one end of the model cabin body is detachably connected with the model bow part, and the other end of the model cabin body is detachably connected with the model stern part; the drag reduction experiment shell comprises a bow shell, a cabin shell and a stern shell, and the bow shell is connected to the outer surface of the model bow in a sleeving mode; a multi-supporting structure is formed through the beam type balance, torque generated at the beam type balance by gravity and buoyancy is avoided, modular installation of the resistance reduction sample piece is achieved, rapid replacement and testing of the sample piece can be achieved, meanwhile, the manufacturing cost is reduced, the testing period is shortened, and the resistance reduction effect of the resistance reduction sample piece at different parts can be tested.

Description

Technical Field

[0001] This invention relates to the field of drag reduction measurement technology for rotating bodies, and in particular to a device and method for measuring the drag reduction effect of a rotating water tunnel. Background Technology

[0002] The magnitude of resistance encountered by equipment during movement is a key indicator for evaluating its performance. It profoundly affects not only the equipment's maneuverability and combat effectiveness but also its energy consumption and endurance. Therefore, in the design and manufacturing of equipment, especially in the field of underwater equipment, effectively reducing motion resistance and improving overall effectiveness has become a core issue to be addressed. As an important tool for underwater combat and exploration, underwater vehicles experience complex total resistance during underwater navigation, but it can be mainly categorized into two types: frictional resistance and form drag. Form drag, as the name suggests, is closely related to the shape design of the vehicle. It is governed by the principles of hydrodynamics and can be optimized to some extent through carefully designed body lines. However, because the design of vehicles must consider multiple functional requirements and overall layout constraints, such as the installation of weapons and equipment and the layout of personnel compartments, the optimization space for form drag is relatively limited, making it difficult to achieve a breakthrough reduction. In contrast, frictional resistance depends more on the physical characteristics of the vehicle hull and its interaction with the surrounding fluid medium. Specifically, the magnitude of frictional drag is influenced by multiple factors, including the wetted surface area of ​​the hull, surface roughness, and the properties and flow state of the fluid medium. At low speeds, frictional drag dominates the total drag, often accounting for 70% to 80%, becoming a major factor limiting vehicle performance improvement. Even at high speeds, frictional drag still accounts for approximately 40% of the total drag, and its impact cannot be ignored. Drag reduction measurement devices can be used to test and compare the drag reduction effects of various technologies. Drag measurement is mainly based on four methods: differential pressure flow drag testing, rotational viscometer tangential stress testing, strain gauge balance testing, and suspension displacement drag testing.

[0003] For example, Chinese invention patent CN114964706A discloses a device and method for measuring the drag reduction effect of high-speed outflow. The above solution involves a micro-integrated manufacturing design of the drag reduction sample and drag reduction model, which results in high overall manufacturing costs. Furthermore, this solution cannot accurately test the drag reduction effect of the technology at different locations, reducing testing efficiency. Additionally, the drag reduction effect test in this solution is subject to torque generated by gravity and buoyancy, further reducing the accuracy of the drag test. Summary of the Invention

[0004] To overcome at least one of the defects described in the prior art, the present invention provides a device and method for measuring the drag reduction effect of a rotating water tunnel. By forming a multi-support structure using a beam balance, torque generated at the beam balance due to gravity and buoyancy is avoided, enabling modular installation of the drag reduction sample. This allows for rapid sample replacement and testing, while reducing manufacturing costs and shortening the testing cycle. Furthermore, it allows for testing the drag reduction effect of the sample at different locations.

[0005] The technical solution of this invention is implemented as follows: A device for measuring the drag reduction effect of a rotating water tunnel includes a rotating model, a drag reduction experimental shell, a balance assembly, and a support assembly. The rotating model comprises a bow, a cabin, and a stern, arranged sequentially. One end of the cabin is detachably connected to the bow, and the other end is detachably connected to the stern. The drag reduction experimental shell includes a bow shell, a cabin shell, and a stern shell. The bow shell is fitted onto the outer surface of the bow, the cabin shell onto the outer surface of the cabin, and the stern shell onto the outer surface of the stern. At least one of the bow shell, the cabin shell, and the stern shell has a drag reduction sample on its outer surface. The support assembly is positioned below the rotating model. The balance assembly is connected between the support assembly and the rotating model.

[0006] Based on the above technical solutions, preferably, the support assembly includes a lower wall panel of the water tunnel and an underwater sealing chamber, wherein a first mounting groove is provided on the lower wall panel of the water tunnel; and the underwater sealing chamber is located below the lower wall panel of the water tunnel.

[0007] Based on the above technical solutions, preferably, the balance assembly includes a beam balance, a balance mounting plate, and balance leveling shims, wherein the balance mounting plate is located in the first mounting slot, and the balance mounting plate has at least two second mounting slots; the number of balance leveling shims is the same as the number of second mounting slots, and one balance leveling shim is placed in each second mounting slot; the number of beam balances is the same as the number of balance leveling shims, the bottom of the beam balances is connected to the balance leveling shims, and the top of the beam balances is connected to the model cabin.

[0008] Based on the above technical solutions, preferably, the outer surface of the beam balance is provided with a guide wing, the guide wing is provided with a through hole for avoiding the beam balance, and the bottom of the guide wing is connected to the balance mounting plate.

[0009] Based on the above technical solutions, preferably, the distance between the inner wall of the through hole and the outer wall of the beam balance is not less than 2mm.

[0010] Based on the above technical solutions, preferably, the guide wing is provided with a threading hole for the wire harness to pass through.

[0011] Based on the above technical solutions, preferably, one end of the model cabin is spirally connected to the model bow, and the other end of the model cabin is spirally connected to the model stern. The bow shell and the model bow, the cabin shell and the model cabin, and the stern shell and the model stern are all connected by fasteners.

[0012] Based on the above technical solutions, preferably, the beam balance includes an upper end cover, a balance body, and a lower end cover, wherein the upper end cover is located inside the model cabin; the top end of the balance body is connected to the upper end cover, and the bottom end of the balance body is connected to the lower end cover; the lower end cover is located in the second mounting groove and is connected to the balance leveling pad.

[0013] A method for measuring the drag reduction effect of a rotating water tunnel, using the aforementioned measuring device for the drag reduction effect of a rotating water tunnel, includes the following steps: S1, preparing a bow shell, a hull shell, and a stern shell as comparison samples; S2-1, preparing a hull shell, a stern shell, and a bow shell with drag reduction samples on its outer surface as a first test sample, obtaining the drag value of the comparison sample and the drag value of the first test sample through drag reduction testing, obtaining the drag reduction rate of the first test sample and the comparison sample, and obtaining the change in drag reduction effect of the bow shell; S2-2, preparing a bow shell, a hull shell, and a bow shell with drag reduction samples on its outer surface as a first test sample. The outer shell of the cabin with drag-reducing samples on its outer surface is used as the second test sample. By conducting drag reduction tests, the drag value of the comparison sample and the drag value of the second test sample are obtained, the drag reduction rate of the second test sample and the comparison sample is obtained, and the change in drag reduction effect of the cabin shell is obtained; S2-3, the bow shell, the cabin shell and the stern shell with drag-reducing samples on their outer surface are prepared as the third test sample. By conducting drag reduction tests, the drag value of the comparison sample and the drag value of the third test sample are obtained, the drag reduction rate of the third test sample and the comparison sample is obtained, and the change in drag reduction effect of the stern shell is obtained.

[0014] In summary, the drag reduction effect measuring device for a rotating water tunnel provided by this invention has the following advantages over the prior art: (1) The model bow, model cabin and model stern in the rotating body model and the bow shell, cabin shell and stern shell in the drag reduction test shell are all detachably connected. This design allows each component to be manufactured and replaced independently. When different types or specifications of drag reduction samples need to be tested, it is not necessary to remanufacture the entire model or shell. Only the corresponding parts need to be replaced, realizing the modular installation of drag reduction samples. This enables the rapid replacement and testing of samples, while reducing manufacturing costs and shortening the testing cycle. (2) By preparing test samples with drag reduction samples in different parts, namely the first test sample, the second test sample and the third test sample, and comparing them with the comparison sample, the drag reduction effect of the bow shell, the cabin shell and the stern shell under different conditions can be accurately obtained, which effectively improves the test efficiency and provides a strong basis for targeted optimization of drag reduction design of each part. (3) In this application, the rotating body model is stably supported and accurately measured by the design of the balance component and the guide wing structure, which effectively reduces the interference of the torque generated by gravity and buoyancy on the test results, thereby improving the accuracy of the drag test and reflecting the actual effect of drag reduction technology more realistically. (4) A gap is left between the inner wall of the through hole and the outer wall of the beam balance to avoid collisions caused by deformation of the beam balance during measurement, which would lead to inaccurate measurement data. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention; Figure 2 This is a cross-sectional structural diagram of an embodiment of the present invention; Figure 3 This is a schematic diagram of the planar structure of an embodiment of the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of the guide vane according to an embodiment of the present invention; Figure 5 This is a top view of the air guide vane according to an embodiment of the present invention; Figure 6 This is a three-dimensional structural diagram of the balance component according to an embodiment of the present invention; Figure 7 This is a top view of the balance mounting plate according to an embodiment of the present invention; Figure 8 This is a three-dimensional structural diagram of the bow shell according to an embodiment of the present invention; Figure 9 This is a three-dimensional structural diagram of a portion of the outer shell of the cabin according to an embodiment of the present invention; Figure 10 This is a three-dimensional structural diagram of another part of the stern shell according to an embodiment of the present invention; Figure 11 This is a three-dimensional structural diagram of the stern shell according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the three-dimensional structure of the bow of a model according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the three-dimensional structure of the model cabin according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the three-dimensional structure of the stern section of the model according to an embodiment of the present invention; Figure 15 This is a three-dimensional structural diagram of the support components and balance mounting plate according to an embodiment of the present invention; Figure 16 This is a three-dimensional structural diagram of the balance mounting plate according to an embodiment of the present invention; Figure 17 This is a three-dimensional structural diagram of the support component according to an embodiment of the present invention; The meanings of the reference numerals in the attached drawings are as follows: 1. Rotating model; 11. Model bow; 12. Model cabin; 13. Model stern; 2. Drag reduction experimental shell; 21. Bow shell; 22. Cabin shell; 221. First cabin shell; 222. Second cabin shell; 23. Stern shell; 3. Balance assembly; 31. Beam balance; 311. Upper end cover; 312. Balance body; 313. Lower end cover; 32. Balance mounting plate; 321. Second mounting slot; 322. Receiving slot; 33. Balance leveling shim; 34. Guide vane; 341. Through hole; 342. Threading hole; 4. Support assembly; 41. Lower wall panel of the water tunnel; 411. First mounting slot; 42. Underwater sealed chamber. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] See Figures 1-17 The present invention discloses a device for measuring the drag reduction effect of a rotating water tunnel, comprising a rotating model 1, a drag reduction experimental shell 2, a balance assembly 3, and a support assembly 4.

[0019] See Figure 1 , Figure 2 , Figure 3 , Figure 12 , Figure 13 and Figure 14As shown, in this embodiment, the rotating body model 1 includes a model bow 11, a model cabin 12, and a model stern 13. The model bow 11, model cabin 12, and model stern 13 are arranged sequentially from one end to the other. One end of the model bow 11 is open, and the interior of the model bow 11 is hollow to facilitate the accommodation of other components. Both ends of the model cabin 12 are open, and the interior of the model cabin 12 is also hollow to facilitate the accommodation of cables, gas-generating devices, or other devices that are inconvenient to extend outside the water tunnel. The end of the model stern 13 closest to the model cabin 12 is open, and the interior of the model stern 13 is also hollow to facilitate the accommodation of other components. Specifically, in this embodiment, one end of the model cabin 12 is detachably connected to the model bow 11, and the other end of the model cabin 12 is detachably connected to the model stern 13; or, both ends of the model cabin 12 are provided with external threads, the open end of the model bow 11 is provided with internal threads, the open end of the model stern 13 is also provided with internal threads, one end of the model cabin 12 is helically connected to the model bow 11, and the other end of the model cabin 12 is helically connected to the model stern 13. Specifically, the internal thread of the model bow 11 is helically connected to the external thread of one end of the model cabin 12, and the internal thread of the model stern 13 is helically connected to the external thread of the other end of the model cabin 12. The detachable spiral connection method simplifies and speeds up the assembly and disassembly of the model bow 11, model cabin 12, and model stern 13. For assembly, simply rotate the external threads at both ends of the model cabin 12 to correspond with the internal threads of the model bow 11 and model stern 13, tightening them accordingly. Disassembly is achieved by simply rotating in the opposite direction to easily separate the parts, eliminating the need for complex tools or procedures and improving work efficiency. Furthermore, the parts can be flexibly adjusted according to actual needs. Different specifications, shapes, or functions of the model bow 11, model cabin 12, or model stern 13 can be replaced to suit different usage scenarios or functional requirements without redesigning and manufacturing the entire model. Simultaneously, the model can be easily expanded, such as by adding additional cabin sections to accommodate more components or achieve more functions, improving the model's adaptability and versatility.

[0020] It should also be noted that the bow section 11, hull section 12, and stern section 13 of the model are made of high-strength, corrosion-resistant aluminum alloy, and the thickness of each section is no less than 5mm. Different experimental scenarios have different strength requirements for the model. Some experiments need to be conducted under harsh conditions, which requires the model to have sufficient strength to withstand these extreme conditions. The high-strength aluminum alloy model with a thickness of no less than 5mm can meet the needs of these high-strength experiments, broadening the scope of experimental applications and enabling the model to play a role in more types of experiments. Moreover, the aluminum alloy material can effectively resist the erosion of corrosive substances in water, preventing rust and corrosion, and extending its service life.

[0021] See Figure 1 , Figure 2 , Figure 3 , Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, in this embodiment, the drag reduction experimental housing 2 includes a bow housing 21, a cabin housing 22, and a stern housing 23. Specifically, the bow housing 21 has the same shape and structure as the model bow 11, and the bow housing 21 is fitted onto the outer surface of the model bow 11; the cabin housing 22 has the same shape and structure as the model cabin 12, and the cabin housing 22 is fitted onto the outer surface of the model cabin 12; the stern housing 23 has the same shape and structure as the model stern 13, and the stern housing 23 is fitted onto the outer surface of the model stern 13. By providing a detachable drag reduction experimental housing 2 on the outer surface of the rotating model 1, test samples can be quickly replaced, improving the efficiency of technology iteration, reducing the manufacturing cost of drag reduction samples, and improving testing efficiency.

[0022] More specifically, in this embodiment, the bow shell 21 is connected to the model bow 11, the cabin shell 22 is connected to the model cabin 12, and the stern shell 23 is connected to the model cabin 12 by fasteners. Specifically, the bow shell 21 and the model bow 11 have corresponding shaft holes, the cabin shell 22 and the model cabin 12 have corresponding shaft holes, and the stern shell 23 and the model stern 13 have corresponding shaft holes. The fasteners are screws, which pass through the shaft holes to achieve a high-strength connection. Moreover, the screws have good shock resistance and can effectively resist the influence of vibration. Furthermore, the screws are easy to disassemble; they only need to be loosened, saving installation and disassembly time and improving experimental efficiency.

[0023] In this embodiment, at least one of the bow shell 21, hull shell 22, and stern shell 23 has a drag-reducing sample on its outer surface. Specifically, the drag-reducing sample can be a drag-reducing coating, a microgroove composite drag-reducing surface, a superhydrophobic composite drag-reducing surface, or a microbubble composite drag-reducing surface. This provides a wider variety of drag-reducing samples, resulting in more comprehensive experimental effects and data. The removable nature of the sample allows for quick replacement and testing, improving efficiency. It should also be noted that drag-reducing samples can be provided on the outer surface of the bow shell 21, the hull shell 22, or the stern shell 23. The thickness of the bow shell 21, hull shell 22, and stern shell 23 is typically 2-5 mm. Using various types of drag-reducing samples, such as drag-reducing coatings, microgroove composite drag-reducing surfaces, superhydrophobic composite drag-reducing surfaces, and microbubble composite drag-reducing surfaces, allows for in-depth research on drag-reducing technology from multiple perspectives and principles. Different types of drag-reduction components possess their own unique drag-reduction mechanisms. For example, drag-reduction coatings may reduce drag by altering the frictional characteristics between the fluid and the surface; microgroove composite drag-reduction surfaces utilize the guiding and regulating effect of microgrooves on fluid flow to reduce drag; superhydrophobic composite drag-reduction surfaces leverage superhydrophobic properties to create a slip layer on the surface, thereby reducing drag; and microbubble composite drag-reduction surfaces reduce drag by generating microbubbles on the surface to alter the fluid boundary layer structure. By comparing the experimental results of these different types of drag-reduction components, a more comprehensive and in-depth understanding of the characteristics and applicable scope of various drag-reduction technologies can be achieved. This provides rich data support for selecting the most suitable drag-reduction scheme in practical applications. The use of detachable connections between the shell and the model, as well as between different parts of the shell, allows for quick and convenient replacement of different types of drag-reduction components during experiments. When testing a particular drag-reduction component, simply install the corresponding shell onto the model; after testing that component, it can be quickly disassembled and replaced with another shell containing a different drag-reduction component to continue the next set of experiments. This rapid replacement capability significantly shortens the experimental cycle and improves experimental efficiency, enabling the testing of multiple drag-reduction prototypes in a shorter time. Furthermore, setting the thickness of the bow shell 21, hull shell 22, and stern shell 23 within the range of 2-5 mm ensures that the shells have sufficient structural strength while minimizing their impact on fluid flow and drag reduction. If the shells are too thick, it increases the overall weight and dimensions of the model, potentially altering the fluid flow around the model and interfering with the test results of the drag-reduction prototypes. Conversely, if the shells are too thin, they may not provide sufficient strength and stability, making them prone to deformation or damage during the experiment, thus affecting the normal progress of the experiment.

[0024] Drag reduction prototypes often exhibit varying drag reduction effects on different surfaces of the bow outer shell 21, hull outer shell 22, and stern outer shell 23, as well as under different thicknesses of these components. Traditional one-piece manufacturing methods are not conducive to testing the drag reduction effects of technologies in different locations. This solution employs a modular design, separating the bow outer shell 21, hull outer shell 22, and stern outer shell 23 into separate sections. This allows for the installation of different drag reduction prototypes and comparative prototypes at different locations, enabling comparisons of the drag reduction effects of different prototypes at various locations and thicknesses. (See reference...) Figure 1 , Figure 2 , Figure 3 , Figure 15 and Figure 17 As shown, the support component 4 is located below the rotating body model 1. The support component 4 includes a water tunnel lower wall plate 41 and an underwater sealing chamber 42. A first mounting groove 411 is provided on the water tunnel lower wall plate 41. The first mounting groove 411 is recessed downward from the top of the water tunnel lower wall plate 41. The underwater sealing chamber 42 is located below the water tunnel lower wall plate 41. A water permeable groove is provided on the first mounting groove 411. The water permeable groove helps to prevent water from flowing from the water permeable groove into the underwater sealing groove. The cables in the experimental device are connected to the outside of the experimental device through watertight connectors and connected to the signal acquisition equipment and power supply equipment. A drain outlet can also be provided at the bottom of the underwater sealing chamber 42 for convenient and rapid drainage.

[0025] See Figure 2 and Figure 6As shown, in this embodiment, the balance assembly 3 is connected between the support assembly 4 and the rotating body model 1. Specifically, the balance assembly 3 includes a beam balance 31, a balance mounting plate 32, and balance leveling shims 33. The balance mounting plate 32 is located within the first mounting groove 411, and its upper surface is flush with the lower surface of the first mounting groove 411. The balance mounting plate 32 has at least two second mounting grooves 321. Specifically, in this embodiment, there are two second mounting grooves 321. The number of balance leveling shims 33 is the same as the number of second mounting grooves 321. In this embodiment, there are also two balance leveling shims 33, and one balance leveling shim 33 is provided in each second mounting groove 321. The number of beam balances 31 is the same as the number of balance leveling shims 33. In this embodiment, two beam balances 31 are provided. The bottom of the beam balances 31 is connected to the balance leveling shims 33, and the bottom of the beam balances 31 is connected to the model chamber 12. The two beam balances 31 are symmetrically and evenly distributed. The two beam balances 31 can reduce friction during measurement and improve the accuracy and reliability of measurement data. The double support structure avoids the torque generated by gravity and buoyancy at the balance, resulting in more accurate test results and better adaptability to high flow rate tests. The balance mounting plate 32 is located in the first mounting groove 411, and its upper surface is flush with the lower surface of the first mounting groove 411. This design allows the balance mounting plate 32 to fit tightly with the support component 4, forming a stable mounting base. The flush surface design reduces gaps and shaking during installation, enhances the connection strength between the balance mounting plate 32 and the support component 4, and ensures that the balance component 3 will not loosen or shift due to vibration or external force during the experiment.

[0026] See Figure 4 , Figure 5 , Figure 7 and Figure 16 As shown, in this embodiment, the outer surface of the beam balance 31 is provided with a guide wing 34, and the guide wing 34 is provided with a through hole 341 for avoiding the beam balance 31. The bottom of the guide wing 34 is connected to the balance mounting plate 32. By providing the guide wing 34, the influence of the beam balance 31 on the smoothness around the model can be reduced. Moreover, the balance mounting plate 32 is provided with a receiving groove 322 that is the same shape as the guide wing 34, and the receiving groove 322 is provided with a hole, which facilitates the fixing effect of the receiving groove 322 and the guide wing 34 through the hole, and prevents the guide wing 34 from shaking.

[0027] The distance between the inner wall of the through hole 341 and the outer wall of the beam balance 31 is not less than 2mm. This design can prevent the beam balance 31 from colliding due to deformation during measurement, which would lead to inaccurate measurement data. The guide vane 34 has a wire-passing hole 342 for the cable harness to pass through. The cable of the beam balance 31 and the cable of the drag-reducing sample are led out from the internal channel of the guide vane 34 through the reserved wire-passing hole 342, without affecting the overall measurement effect.

[0028] See Figure 2 and Figure 6 As shown, in this embodiment, the beam balance 31 includes an upper cover 311, a balance body 312, and a lower cover 313. The upper cover 311 is located inside the model cabin 12. Specifically, the cabin shell 22 includes a first cabin shell 22 and a second cabin shell 222, which are joined to form a ring. Slots are provided at the connection between the first cabin shell 22 and the second cabin shell 222, as well as on the model cabin 12, to avoid the upper cover 311. The top of the balance body 312 is connected to the upper end cover 311, and the bottom of the balance body 312 is connected to the lower end cover 313. The lower end cover 313 is located in the second mounting groove 321 and is connected to the balance leveling shim 33. In this embodiment, the upper end cover 311 and the top of the balance body 312 are connected by screws and fixed to the model cabin 12. The bottom of the beam balance 31 is connected to the balance mounting plate 32 by screws, and the overall height can be adjusted by the balance leveling shim 33.

[0029] This invention also discloses a method for measuring the drag reduction effect of a rotating body water tunnel, using the aforementioned rotating body water tunnel effect measurement device, comprising the following steps: S1. Prepare the bow shell 21, the hull shell 22, and the stern shell 23 as comparative samples; S2-1. Prepare the outer shell 22, the stern shell 23, and the bow shell 21 with drag-reducing samples on its outer surface as the first test sample. By conducting drag reduction tests, obtain the drag value of the comparison sample and the drag value of the first test sample, obtain the drag reduction rate of the first test sample and the comparison sample, and obtain the change in drag reduction effect of the bow shell 21. It should be noted that the drag-reducing samples include, but are not limited to, drag-reducing coatings, microgroove composite drag-reducing surfaces, superhydrophobic composite drag-reducing surfaces, or microbubble composite drag-reducing surfaces. Moreover, the outer shell 22, the stern shell 23, the bow shell 21 with drag-reducing samples on its outer surface, and the comparison sample can also be shells of different thicknesses to facilitate monitoring the measurement effect of shells of different thicknesses. S2-2. Prepare the bow shell 21, stern shell 23, and the hull shell 22 with drag-reducing samples on their outer surfaces as the second test samples. By conducting drag reduction tests, obtain the drag value of the comparison sample and the drag value of the second test sample, obtain the drag reduction rate of the second test sample and the comparison sample, and obtain the change in drag reduction effect of the hull shell 22. It should be noted that the drag-reducing samples include, but are not limited to, drag-reducing coatings, microgroove composite drag-reducing surfaces, superhydrophobic composite drag-reducing surfaces, or microbubble composite drag-reducing surfaces. Moreover, the bow shell 21, stern shell 23, the hull shell 22 with drag-reducing samples on their outer surfaces, and the comparison sample can also be shells of different thicknesses to facilitate monitoring the measurement effect of shells of different thicknesses. S2-3. Prepare the bow shell 21, the hull shell 22, and the stern shell 23 with drag-reducing samples on their outer surfaces as the third test sample. By conducting drag reduction tests, obtain the drag value of the comparison sample and the drag value of the third test sample, obtain the drag reduction rate of the third test sample and the comparison sample, and obtain the change in drag reduction effect of the stern shell 23. It should be noted that the drag-reducing samples include, but are not limited to, drag-reducing coatings, microgroove composite drag-reducing surfaces, superhydrophobic composite drag-reducing surfaces, or microbubble composite drag-reducing surfaces. Moreover, the bow shell 21, the hull shell 22, the stern shell 23 with drag-reducing samples on their outer surfaces, and the comparison sample can also be shells of different thicknesses to facilitate monitoring the measurement effect of shells of different thicknesses.

[0030] In the above scheme, the drag reduction rate Dr1 of the first test sample and the control sample is: ; The drag reduction ratio Dr2 of the second test sample and the control sample is: ; The drag reduction ratio Dr3 of the second test sample and the control sample is: ; The drag reduction effect of the sample on the bow shell 21, hull shell 22 and stern shell 23 is obtained by the above formula. If Dr1 is the largest, it means that the drag reduction effect of the bow shell 21 is the best; if Dr2 is the largest, the drag reduction effect of the hull shell 22 is the most significant; if Dr3 is the largest, it means that the drag reduction effect of the stern shell 23 is the best.

[0031] The specific implementation steps are as follows: First, install the first test sample into the rotating water tunnel effect measurement device, ensuring a secure and accurate installation. Adjust the experimental parameters of the water tunnel, such as flow rate, water temperature, and water quality, to meet the predetermined experimental conditions. Start the water tunnel, allowing water to flow through the test sample at a set speed. Simultaneously, use the balance component 3 in the measurement device to accurately measure the resistance experienced by the first test sample. During the measurement process, ensure the stability of the experimental environment, avoid interference from external factors, and obtain the drag reduction rate Dr1. Next, install the second test sample into the rotating water tunnel effect measurement device, repeat the experimental steps in S2-1 above, adjust the water tunnel parameters, start the water tunnel to measure resistance, and obtain the drag reduction rate Dr2. Finally, install the third test sample into the measurement device, repeat the experimental steps in S2-1 above, adjust the water tunnel parameters, start the water tunnel to measure resistance, and obtain the drag reduction rate Dr3. Compare the drag reduction rates after setting drag reduction samples on different parts of the outer shell, and analyze the differences and mutual influences of the drag reduction effects at each part.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for measuring the drag reduction effect of a rotating water tunnel, characterized in that, It includes a rotating model (1), a drag-reducing experimental shell (2), a balance assembly (3), and a support assembly (4), wherein, The rotating model (1) includes a model bow (11), a model cabin (12) and a model stern (13) arranged in sequence. One end of the model cabin (12) is detachably connected to the model bow (11), and the other end of the model cabin (12) is detachably connected to the model stern (13). The drag reduction experimental shell (2) includes a bow shell (21), a cabin shell (22), and a stern shell (23). The bow shell (21) is fitted onto the outer surface of the model bow (11), the cabin shell (22) is fitted onto the outer surface of the model cabin (12), and the stern shell (23) is fitted onto the outer surface of the model stern (13). At least one of the bow shell (21), the cabin shell (22), and the stern shell (23) has a drag reduction sample provided on its outer surface. The support component (4) is disposed below the rotating body model (1); The balance component (3) is connected between the support component (4) and the rotating body model (1).

2. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 1, characterized in that, The support assembly (4) includes a lower wall panel (41) of the water tunnel and an underwater sealed chamber (42), wherein, The lower wall panel (41) of the water tunnel is provided with a first installation groove (411); The underwater sealed chamber (42) is located below the lower wall panel (41) of the water tunnel.

3. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 2, characterized in that, The balance assembly (3) includes a beam balance (31), a balance mounting plate (32), and balance leveling shims (33), wherein, The balance mounting plate (32) is located in the first mounting slot (411), and at least two second mounting slots (321) are provided on the balance mounting plate (32); The number of the balance leveling pads (33) is the same as the number of the second mounting slots (321), and one balance leveling pad (33) is placed in one of the second mounting slots (321); The number of beam balances (31) is the same as the number of balance leveling pads (33). The bottom of the beam balances (31) is connected to the balance leveling pads (33), and the top of the beam balances (31) is connected to the model cabin (12).

4. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 3, characterized in that, The outer surface of the beam balance (31) is provided with a flow guide wing (34), and the flow guide wing (34) is provided with a through hole (341) for avoiding the beam balance (31). The bottom of the flow guide wing (34) is connected to the balance mounting plate (32).

5. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 4, characterized in that, The distance between the inner wall of the through hole (341) and the outer wall of the beam balance (31) is not less than 2 mm.

6. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 4, characterized in that, The guide vane (34) has a threading hole (342) for the wire harness to pass through.

7. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 1, characterized in that, One end of the model cabin (12) is spirally connected to the model bow (11), and the other end of the model cabin (12) is spirally connected to the model stern (13). The bow shell (21) and the model bow (11), the cabin shell (22) and the model cabin (12), and the stern shell (23) and the model stern (13) are all connected by fasteners.

8. The device for measuring the drag reduction effect of a rotating water tunnel according to claim 3, characterized in that, The beam balance (31) includes an upper end cap (311), a balance body (312), and a lower end cap (313), wherein, The upper end cap (311) is located inside the model cabin (12); The top end of the balance body (312) is connected to the upper end cover (311), and the bottom end of the balance body (312) is connected to the lower end cover (313). The lower end cap (313) is located in the second mounting groove (321) and is connected to the balance leveling pad (33).

9. A method for measuring the drag reduction effect of a rotating water tunnel, characterized in that, The method of measuring the drag reduction effect of a rotating water tunnel as described in any one of claims 1-8 includes the following steps: S1. Prepare the bow shell (21), hull shell (22) and stern shell (23) as comparative samples; S2-1. Prepare the outer shell (22), stern shell (23) and bow shell (21) with drag reduction sample on its outer surface as the first test sample. By conducting drag reduction test, obtain the drag value of the comparison sample and the drag value of the first test sample, obtain the drag reduction rate of the first test sample and the comparison sample, and obtain the change of drag reduction effect of the bow shell (21). S2-2. Prepare the bow shell (21), stern shell (23) and the cabin shell (22) with drag reduction sample on its outer surface as the second test sample. By conducting drag reduction test, obtain the drag value of the comparison sample and the drag value of the second test sample, obtain the drag reduction rate of the second test sample and the comparison sample, and obtain the change of drag reduction effect of the cabin shell (22). S2-3. Prepare the bow shell (21), the cabin shell (22) and the stern shell (23) with drag reduction sample on its outer surface as the third test sample. By conducting drag reduction test, obtain the drag value of the comparison sample and the drag value of the third test sample, obtain the drag reduction rate of the third test sample and the comparison sample, and obtain the change of drag reduction effect of the stern shell (23).

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