Rectification plate for fixing lower end of rudder of underwater vehicle and design method and system thereof

Abstract

The invention discloses a rectifying plate for fixing the lower end of an underwater vehicle rudder and a design method and system thereof, and the method comprises the steps: determining the installation position of the rectifying plate, and preliminarily determining the overlook shape and size of the rectifying plate; establishing a three-dimensional model of the underwater vehicle and a rudder, determining a flow field and a streamline shape near the mounting position of the rectifying plate by using a CFD (computational fluid dynamics) method, and determining a side shape of the rectifying plate; carrying out optimization design on the parameters of the rectifying plate; performing hydrodynamic analysis on the numerical calculation models of the underwater navigation body, the rudder and the propeller, and determining a final design scheme of the rectifying plate by combining a plurality of indexes. By installing and fixing the rectifying plate at the lower end of the rudder of the underwater navigation body, the streaming phenomenon of the lower end face of the rudder can be effectively restrained, transverse flowing of the rudder is reduced, fluid turbulence is reduced, and the lift force and efficiency of the rudder are improved. Due to the arrangement of the rectifying plates, circulation loss is avoided, namely, the aspect ratio of the rudder is increased, the lift force of the rudder is improved, and therefore the rudder effect is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater vehicle maneuverability, and in particular to a rectifier plate used for fixing the lower end of a rudder of an underwater vehicle, and a design method and system thereof. Background Art

[0002] The two main warships of the modern navy are surface ships and submarines. Due to their special combat environment and combat requirements, the maneuverability and concealment of submarines are of vital importance. Submarines mainly rely on rudders to achieve horizontal turning movement and vertical diving and buoyancy movement. The working principle of the rudder is that after the rudder is turned, the hydrodynamic force on the rudder provides a vertical force or lateral force perpendicular to the hull, thereby achieving movement. Therefore, the performance of the rudder directly affects the maneuverability of the submarine. However, there are some inherent problems in the traditional rudder design, especially when the submarine is sailing at high speed and maneuvering, these problems are particularly prominent.

[0003] At present, the rudder of a submarine usually adopts a design similar to that of a wing with a small aspect ratio, which makes it easy for the rudder to have a lateral flow when working, resulting in a strong lateral flow around the rudder end. This flow around will not only reduce the velocity circulation in the direction of the rudder chord length and the effective angle of attack, but also increase the induced drag, which will have an adverse effect on the lift and efficiency of the rudder. In addition, during the straight-line navigation of the underwater vehicle, due to the influence of the ocean current and the steering gear clearance, the rudder angle needs to be adjusted within a small range through the automatic control system to maintain the straight-line state. This makes the rudder angle of the underwater vehicle not always zero degrees when sailing straight, but is in a small range of changes, which further increases the complexity of the rudder work.

[0004] In the existing technical solutions, due to the existence of the rudder angle, the gap between the lower end surface of the rudder and the fixed wing below will be significantly increased. At the same time, there will be a certain pressure difference on the two sides of the rudder, which will cause the fluid on the lower end surface of the rudder to flip and form a strong vortex, causing the rudder to vibrate and increase the noise of the rudder. In addition, the vibration noise of the underwater vehicle mostly comes from the stern, mainly including mechanical noise, propulsion noise and hydrodynamic noise, among which the propeller hydrodynamic noise is particularly serious. Due to the unevenness of the flow field at the propeller disk, the lateral flow generated by the rudder of the underwater vehicle and the vortex formed by the fluid flipping will cause turbulence in the flow field behind the rudder, increase the unevenness of the flow field at the propeller disk, aggravate the vibration and noise of the propeller, reduce the propeller propulsion efficiency, and have an adverse effect on the stealth and speed of the submarine. These problems are exactly the key points to be solved by the present invention. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the purpose of the present invention is to provide a straightening plate fixed at the lower end of the rudder of an underwater vehicle and a design method and system thereof. The straightening plate can be installed and fixed at the lower end of the rudder of the underwater vehicle, which can effectively suppress the flow around the lower end face of the rudder, reduce the lateral flow of the rudder, and prevent the fluid from flipping and forming a separation vortex at a small rudder angle, thereby reducing the fluid turbulence and improving the lift and efficiency of the rudder. The existence of the straightening plate avoids the loss of circulation, which is equivalent to increasing the aspect ratio of the rudder, improving the lift of the rudder, and reducing the induced drag without increasing the overall drag, thereby significantly improving the rudder efficiency. Since the straightening plate can suppress the flow around the rudder end, the turbulence of the flow field behind the rudder is reduced, and the flow field behind the rudder becomes more uniform, thereby reducing the impact on the propeller disc flow field. The propeller movement environment becomes more stable, the propeller exciting force and noise are reduced, thereby improving the propulsion efficiency of the propeller, and also helping to extend the service life of the propeller.

[0006] According to a first aspect of the present invention, there is provided a design method for fixing a fairing at the lower end of a rudder of an underwater vehicle, comprising:

[0007] S100, determining the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determining the top view shape and size of the fairing;

[0008] S200, establishing a three-dimensional model of the underwater vehicle and the rudder, using a CFD (computational fluid dynamics) method to determine the flow field and streamline shape near the installation position of the fairing, and determining the side shape of the fairing according to the flow field and streamline shape;

[0009] S300, taking the rudder end flow suppression effect as the goal, considering the influence of the fairing on the rudder lift and drag, using the CFD method to optimize the installation position, top view shape, size and side shape of the fairing, determine the preliminary design scheme of the fairing, and optimize the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle;

[0010] S400, considering the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishing a numerical calculation model of the underwater vehicle, the rudder and the propeller, evaluating the influence of the propeller on the rectifier, and adjusting the parameters of the rectifier;

[0011] S500, performing hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determining the final design of the fairing in combination with maneuverability, rapidity and stealth indicators.

[0012] Furthermore, step S100 includes:

[0013] S101, determining the relative position of the fairing on the navigation body according to the installation position of the rudder and the gap between the fairing and other components of the navigation body, and fine-adjusting the installation position and angle of the fairing according to the flow field characteristics;

[0014] S102. Determine the top view shape of the rectifier plate according to the design requirements, and preliminarily estimate the size of the rectifier plate according to relevant specifications or empirical formulas, and adjust and optimize it in the subsequent process;

[0015] Further, step S200 includes:

[0016] S201, using three-dimensional modeling software to establish underwater navigation body and rudder models, and meshing the models;

[0017] S202. Import into professional CFD software, set boundary conditions according to actual working conditions, run CFD simulation, monitor convergence and stability during simulation, and analyze flow field and streamline shape at the installation position of rectifier plate;

[0018] S203: Determine the side shape of the rectifier plate according to the flow field and streamline shape at the installation position of the rectifier plate.

[0019] Furthermore, step S201 includes: appropriately simplifying the model according to the needs of CFD simulation, and removing details that have little effect on fluid flow.

[0020] Further, step S300 includes:

[0021] S301, based on experience and preliminary simulation results, design preliminary solutions for rectifiers with various geometric parameters, evaluate the influence of rectifiers on rudder lift and drag according to steps S201-S202, and after each calculation converges, continuously adjust rectifier parameters according to simulation results and seek the best solution;

[0022] S302, adjusting the parameters of the parent type rectifier plate to check the influence of different parameters on the flow field uniformity of the propeller blade disc, comparing the flow field uniformity of the propeller blade disc surface after the parent type rectifier plate is optimized with the flow field uniformity of the original propeller blade disc surface, and evaluating the improvement effect.

[0023] Further, step S400 includes:

[0024] S401. On the basis of step S301, according to the specific parameters and layout of the thrusters, corresponding thrusters are added to the model to establish a numerical calculation model of the underwater vehicle, rudder, fairing, and thruster.

[0025] S402, using a CFD solver to solve the numerical calculation model, obtain detailed flow information of the flow field around the rectifier, analyze the specific impact of the thruster suction effect on the flow field around the rectifier, and evaluate the potential impact of these impacts on the performance of the rectifier.

[0026] S403. Based on the numerical simulation results, identify the key parameters that have a greater impact on the performance of the rectifier, make preliminary adjustments to the key parameters, re-perform numerical simulation to evaluate the adjustment effect, and perform numerical simulation verification on the optimized rectifier to ensure that it can minimize the impact of the suction effect of the thruster while meeting the design requirements.

[0027] According to the second aspect of the present invention, there is provided a straightening plate for fixing the lower end of the rudder of an underwater vehicle, which is implemented by applying the above-mentioned design method for fixing the straightening plate at the lower end of the rudder of an underwater vehicle. It can effectively suppress the flow around the lower end surface of the rudder of the underwater vehicle, reduce the lateral flow of the rudder, and prevent the fluid from flipping over at the rudder end to form a separation vortex when the rudder angle is small; the straightening plate is arranged in the gap between the rear end of the stabilizing wing and the rotating rudder, and is installed on the upper end surface of the stabilizing wing. The plane is perpendicular to the rudder surface, and the side shape is the same as the streamline shape at the installation position.

[0028] Furthermore, the top view shape of the fairing can be changed accordingly according to the flow field near the rudder.

[0029] Furthermore, the top view shape of the fairing can adopt a specific airfoil shape or be the same as the rudder wing section to maximize the benefit of the fairing.

[0030] According to a third aspect of the present invention, there is provided a design system for fixing a fairing at the lower end of a rudder of an underwater vehicle, comprising:

[0031] The first module determines the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determines the top view shape and size of the fairing;

[0032] The second module is to establish a three-dimensional model of the underwater vehicle and the rudder, use a computational fluid dynamics method to determine the flow field and streamline shape near the installation position of the fairing, and determine the side shape of the fairing according to the flow field and streamline shape;

[0033] The third module takes the rudder end flow suppression effect as the goal, considers the influence of the fairing on the rudder lift and drag, uses the computational fluid dynamics method to optimize the installation position, top view shape, size and side shape of the fairing, determines the preliminary design scheme of the fairing, and optimizes the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle;

[0034] The fourth module considers the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishes the numerical calculation model of the underwater vehicle, rudder and propeller, evaluates the influence of the propeller on the rectifier, and adjusts the parameters of the rectifier;

[0035] The fifth module is to conduct hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determine the final design of the fairing in combination with the maneuverability, rapidity and stealth indicators.

[0036] Beneficial effects of the present invention:

[0037] 1. The fairing proposed in the present invention can be fixed on the lower end of the rudder of the underwater navigation body, which can effectively suppress the flow around the lower end face of the rudder, reduce the lateral flow of the rudder, and prevent the fluid from flipping and forming a separation vortex at a small rudder angle, thereby reducing fluid turbulence and improving the lift and efficiency of the rudder. The presence of the fairing avoids the loss of circulation, which is equivalent to increasing the aspect ratio of the rudder, improving the lift of the rudder, and reducing the induced drag without increasing the overall drag, thereby significantly improving the rudder efficiency. Since the fairing can suppress the flow around the rudder end and reduce the turbulence of the flow field behind the rudder, the flow field behind the rudder becomes more uniform, thereby reducing the impact on the propeller disc flow field. The propeller movement environment becomes more stable, the propeller exciting force and noise are reduced, thereby improving the propulsion efficiency of the propeller, and also helping to extend the service life of the propeller.

[0038] 2. The rectifier design method proposed in the present invention can improve the uniformity of the flow field at the propeller disk surface, reduce the propeller exciting force and radiation noise, and thus improve the stealth of the underwater vehicle by optimizing the design of the rectifier. In addition, since the rectifier provides a stable torque, it can help maintain the navigation stability of the underwater vehicle, reduce unnecessary rudder movements, and help improve navigation speed and stability.

[0039] 3. The rectifier plate proposed by the present invention has a simple structure and is easy to install. Its design can flexibly adapt to the needs of different types of rudders. It can be integrated in the design stage or designed and installed on the basis of existing rudders. It is an effective remedial measure for defective rudders. In summary, the present invention achieves a comprehensive improvement in the maneuverability, stealth and propulsion efficiency of underwater navigation bodies by rationally designing rectifier plates.

[0040] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0042] Figure 1 This is a flow chart of a method for designing a rectifier plate for fixing the lower end of a rudder of an underwater vehicle in an embodiment of the present invention;

[0043] Figure 2 is a vortex distribution cloud diagram of the end plate-free solution at the propeller disk surface in an embodiment of the present invention;

[0044] Figure 3 is a vortex distribution cloud diagram of the end plate at the propeller disk surface in the first embodiment of the present invention;

[0045] Figure 4 is a vortex distribution cloud diagram of the end plate at the propeller disk surface in scheme 2 of the embodiment of the present invention;

[0046] Figure 5 is a vortex distribution cloud diagram of the third end plate at the propeller disk surface in the embodiment of the present invention;

[0047] Figure 6 is a vortex distribution cloud diagram of the end plate of scheme 4 at the propeller disk surface in the embodiment of the present invention;

[0048] Figure 7 is a cloud diagram of the axial velocity distribution at the propeller disk surface of the end plate-free solution in the embodiment of the present invention;

[0049] Figure 8 is a cloud diagram of the axial velocity distribution of the end plate at the propeller disk surface in the first embodiment of the present invention;

[0050] Fig. 9 is a cloud diagram of the axial velocity distribution of the end plate at the propeller disk surface in the second embodiment of the present invention;

[0051] Fig.10 is a cloud diagram of the axial velocity distribution of the third end plate at the propeller disk surface in the embodiment of the present invention;

[0052] Fig.11 is a cloud diagram of the axial velocity distribution of the end plate of scheme 4 at the propeller disc surface in the embodiment of the present invention;

[0053] Fig.12 is a cloud diagram of the circumferential velocity distribution at the propeller disk surface of the end plate-free solution in the embodiment of the present invention;

[0054] Fig.13 is a cloud diagram of the circumferential velocity distribution of the end plate at the propeller disk surface in the first embodiment of the present invention;

[0055] Fig.14 is a cloud diagram of the circumferential velocity distribution of the end plate at the propeller disk surface in the second embodiment of the present invention;

[0056] Fig.15 is a cloud diagram of the circumferential velocity distribution of the third end plate at the propeller disk surface in the embodiment of the present invention;

[0057] Fig.16 is a cloud diagram of the circumferential velocity distribution of the end plate of scheme 4 at the propeller disk surface in the embodiment of the present invention;

[0058] Fig.17 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.37m in the embodiment of the present invention;

[0059] Fig.18 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.39m in the embodiment of the present invention;

[0060] Fig.19 : is a comparison diagram of axial velocity distribution of various schemes at a radius of R = 0.40m in the embodiment of the present invention;

[0061] Fig. 20 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.41m in the embodiment of the present invention;

[0062] Fig.21 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.42m in the embodiment of the present invention;

[0063] Fig. 22 is a comparison diagram of axial velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.43m;

[0064] Fig.23 : is a comparison diagram of axial velocity distribution of various schemes at a radius of R = 0.44m in the embodiment of the present invention;

[0065] Fig.24 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.45m in the embodiment of the present invention;

[0066] Fig.25 is a comparison diagram of axial velocity distribution of various schemes at a radius of R=0.47m in the embodiment of the present invention;

[0067] Fig.26 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.37m;

[0068] Fig. 27 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.39m;

[0069] Fig.28 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.40m;

[0070] Fig.29 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.41m;

[0071] Fig.30 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.42m;

[0072] Fig.31 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.43m;

[0073] Fig.32 is a comparison diagram of the circumferential velocity distribution of each scheme at a radius R=0.44m in the embodiment of the present invention;

[0074] Fig.33 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.45m;

[0075] Fig.34 is a comparison diagram of the circumferential velocity distribution of various schemes in the embodiment of the present invention at a radius R=0.47m;

[0076] Fig.35 Schematic diagram of the geometric shape of a conventional rudder of an underwater vehicle in an embodiment of the present invention;

[0077] Fig.36 Schematic diagram of the geometric shape of the underwater vehicle rudder with a fairing in an embodiment of the present invention;

[0078] Fig.37 Schematic diagram of the streamline shape of the lower end surface of the rudder of an underwater vehicle with a fairing in an embodiment of the present invention

[0079] Fig.38 Schematic diagram of the geometric shape of the underwater vehicle rudder with a straightening plate in the embodiment of the present invention

[0080] Fig.39 Schematic diagram of the geometric shape of the underwater vehicle rudder with the second solution rectifier in the embodiment of the present invention

[0081] Fig.40 Schematic diagram of the geometric shape of the underwater vehicle rudder with the third solution rectifier added in the embodiment of the present invention;

[0082] Fig.41 It is a schematic diagram of the geometric shape of the underwater vehicle rudder with a fourth-scheme rectifier in an embodiment of the present invention. DETAILED DESCRIPTION

[0083] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0084] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0085] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as in the embodiments of this application.

[0086] The present invention provides a rectifying plate for fixing the lower end of the rudder of an underwater vehicle and a design method and system thereof. By installing and fixing the rectifying plate at the lower end of the rudder of the underwater vehicle, the flow around the lower end surface of the rudder can be effectively suppressed, the lateral flow of the rudder can be reduced, and the fluid flipping at a small rudder angle can be prevented to form a separation vortex, thereby reducing the fluid turbulence and improving the lift and efficiency of the rudder. The existence of the rectifying plate avoids the circulation loss, which is equivalent to increasing the aspect ratio of the rudder, improving the lift of the rudder, and reducing the induced drag without increasing the overall drag, thereby significantly improving the rudder efficiency. Since the rectifying plate can suppress the flow around the rudder end, the turbulence of the flow field behind the rudder is reduced, and the flow field behind the rudder becomes more uniform, thereby reducing the impact on the propeller disk flow field. The propeller motion environment becomes more stable, the propeller exciting force and noise are reduced, thereby improving the propulsion efficiency of the propeller, and also helping to extend the service life of the propeller. By optimizing the design of the rectifying plate, the uniformity of the flow field at the propeller disk can be improved, the propeller exciting force and radiation noise can be reduced, thereby improving the stealth of the underwater vehicle. In addition, since the fairing provides a stable torque, it can help maintain the navigation stability of the underwater vehicle, reduce unnecessary rudder movements, and help improve navigation speed and stability.

[0087] Embodiment 1:

[0088] like Figure 1 As shown, an embodiment of the present invention provides a method for designing a rectifier plate for fixing the lower end of a rudder of an underwater vehicle, comprising:

[0089] S100, determining the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determining the top view shape and size of the fairing;

[0090] Step S100 specifically includes:

[0091] S101. The installation position of the fairing is mainly determined by the installation position of the rudder and the flow field characteristics. The installation position of the fairing should be close to the lower end of the rudder to improve the flow field characteristics near the rudder. According to the installation position of the rudder, determine the relative position of the fairing on the navigation body. The fairing should be parallel to the rudder surface and located near the lower edge of the rudder. At the same time, consider the gap between the fairing and other parts of the navigation body (such as the tail structure, propeller, etc.) to ensure that there is no mutual interference. At the same time, according to the flow field characteristics, fine-tune the installation position and angle of the fairing to minimize resistance and improve stability.

[0092] S102. Although the shape of the rectifier may vary due to design requirements, it is generally rectangular. The main function of the rectifier is to rectify the water flow passing through the rudder surface, reduce turbulence and eddies, and thus improve the efficiency of the rudder and the navigation performance of the submarine. The rectangular shape can better adapt to the direction and speed changes of the fluid to achieve this goal. At the same time, the rectangular structure has good mechanical stability, can resist the impact and vibration of the fluid, and maintain the balance and stability of the rudder surface. If the rudder adopts an asymmetric airfoil, the rectifier should also be designed to be an asymmetric shape to match the flow field characteristics of the rudder.

[0093] S103. The width b of the rectifier is a key parameter that directly affects the rectifier effect. It can be preliminarily estimated by referring to relevant specifications or empirical formulas. The optimal ratio of the width of the rectifier to the chord length of the rudder section is 0.07. The preliminary estimate of the width b should be used as the starting point for subsequent design and simulation, and should be adjusted and optimized as needed in the subsequent process.

[0094] S200, establishing a three-dimensional model of the underwater vehicle and the rudder, using a CFD (computational fluid dynamics) method to determine the flow field and streamline shape near the installation position of the fairing, and determining the side shape of the fairing according to the flow field and streamline shape;

[0095] Step S200 specifically includes:

[0096] S201. Use 3D modeling software (such as SolidWorks, Catia, etc.) to build underwater vehicle and rudder models. The models should have high precision and accurately reflect the size and shape of the vehicle and the position and size of the rudder. At the same time, according to the needs of CFD simulation, the model can be appropriately simplified to remove details that have little effect on fluid flow.

[0097] S202. Use CFD pre-processing software to mesh the model. Mesh quality is critical to the accuracy and efficiency of CFD calculations, so ensure that the mesh has sufficient density and resolution at the rectifier installation location. The mesh type can be structured or unstructured, depending on the complexity of the model and computing resources. For areas with complex shapes, the method of local mesh encryption can be used to improve the calculation accuracy.

[0098] S203. Import the mesh into professional CFD software (such as ANSYS Fluent, STAR-CCM+, etc.), which should be capable of handling complex flow problems. After importing, set boundary conditions according to actual working conditions. Run CFD simulation, monitor convergence and stability during the simulation process, and ensure that the simulation results are reliable. Analyze the flow field and streamline shape at the installation position of the rectifier, focusing on velocity vector distribution, vortex distribution, etc.

[0099] S204. Design the side shape of the rectifier according to the streamline shape obtained by CFD simulation. In step S102, it has been preliminarily determined that the shape of the rectifier is a rectangle, so only two shapes of the end plate cross-section, "I" shape or "[" shape, are considered here.

[0100] S300, taking the rudder end flow suppression effect as the goal, considering the influence of the fairing on the rudder lift and drag, using the CFD method to optimize the installation position, top view shape, size and side shape of the fairing, determine the preliminary design scheme of the fairing, and optimize the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle;

[0101] Step S300 specifically includes:

[0102] S301. Based on experience and preliminary simulation results, design preliminary solutions for rectifier plates with several different geometric parameters.

[0103] S302, according to steps S201-S203, the influence of the rectifier plate on the rudder lift and drag is evaluated. After each calculation convergence, the parameters of the rectifier plate, such as the installation position, width and thickness distribution, are continuously adjusted according to the simulation results to seek the best solution. The rectifier plate can be used as the mother rectifier plate for subsequent optimization.

[0104] S303, analyzing the uniformity of the flow field of the propeller disk of the underwater vehicle to understand the influence of the uniformity of the propeller disk on the navigation performance. Adjusting the parameters of the parent rectifier to see the influence of different parameters on the uniformity of the flow field of the propeller disk, comparing the uniformity of the flow field of the propeller disk after the parent rectifier is optimized with the uniformity of the flow field of the original propeller disk, and evaluating the improvement effect.

[0105] S400, considering the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishing a numerical calculation model of the underwater vehicle, the rudder and the propeller, evaluating the influence of the propeller on the rectifier, and adjusting the parameters of the rectifier;

[0106] Step S400 specifically includes:

[0107] S401. On the basis of step S302, according to the specific parameters and layout of the thrusters, corresponding thrusters are added to the model to establish a numerical calculation model of the underwater vehicle, rudder, fairing, and thruster.

[0108] S402. Use the CFD solver to solve the established numerical calculation model to obtain detailed flow information of the flow field around the rectifier. Focus on the flow parameters such as pressure distribution, velocity vector, and vortex distribution before and after the rectifier, analyze the specific impact of the thruster suction on the flow field around the rectifier, including pressure difference, flow velocity change, vortex generation and shedding, etc., and evaluate the potential impact of these effects on the performance of the rectifier (such as resistance and stability).

[0109] S403. Based on the numerical simulation results, identify the key parameters that have a greater impact on the performance of the rectifier (such as the position, shape, size, etc. of the rectifier), make preliminary adjustments to the key parameters, and re-perform numerical simulation to evaluate the adjustment effect. Perform numerical simulation verification on the optimized rectifier to ensure that it can minimize the impact of the suction effect of the thruster while meeting the design requirements.

[0110] S500, performing hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determining the final design of the fairing in combination with maneuverability, rapidity and stealth indicators.

[0111] Embodiment 2:

[0112] like Fig.35 As shown in the figure, when the underwater vehicle is sailing straight, due to the influence of the sea current and the clearance between the steering gear, in order to maintain the straight course, the rudder angle will be adjusted within a small range through automatic control. Therefore, the rudder angle of the underwater vehicle is not always at 0° when sailing straight, but will be in a small range of changes. After a certain range of rudder angle, the gap between the lower end surface of the rudder and the fixed wing below will increase significantly. At the same time, due to the existence of the rudder angle, there will be a certain pressure difference between the two sides of the rudder, which will cause the fluid to flip on the lower end surface of the rudder to form a strong vortex. The vortex flows backward to the rotor disk of the pump-jet propeller, resulting in an increase in the circumferential unevenness of the flow field on the rotor disk, thereby increasing the exciting force and radiation noise of the propeller.

[0113] like Fig.36As shown, in order to solve the above problems, based on the first embodiment, this embodiment proposes a fixed rectifier plate at the lower end of the rudder of an underwater vehicle, which is used to reduce the fluid flipping caused by the large gap at the lower end of the rudder, thereby reducing the non-uniformity of the flow field at the rotor disk surface, and reducing the exciting force and radiation noise of the propeller. The rectifier plate is arranged at the gap between the rear end of the conventional rudder stabilizing wing of the underwater vehicle and the rotating rudder, and a fixed wing plate is installed on the upper end of the stabilizing wing.

[0114] like Fig.37 As shown in Figure 1, a certain actual model is taken as the research object, and the overall structural grid calculation model of the hull and the rudder is established. The flow field around the hull is calculated under the navigation condition of Vs = 12kn, n = 500rpm (Vs is the speed of the underwater navigation body, and n is the propeller speed). The shape of the streamline near the lower end surface of the rudder is calculated, and the vertical coordinates of the streamline at each longitudinal position are shown in Table 1, where x = 16.763 is the longitudinal coordinate at the starting point of the streamline, and x = 17.352 is the coordinate at the trailing edge of the rudder.

[0115] Table 1

[0116] x y z 1 16.763 0.676 0.1 2 17.062 0.62 0.04 3 17.352 0.559 0.005

[0117] Therefore, the line connecting the two points (16.763, 0.676, 0) and (17.352, 0.559, 0) is taken as the end plate generatrix of the end plate at the lower end face of the rudder.

[0118] like Figure 38-Figure 41 As shown, this embodiment proposes four rectification end plate solutions, and the main technical parameters of the end plates are shown in Table 2.

[0119] Table 2

[0120]

[0121] In order to consider the influence of the end plate on the flow field of the rotor disk, only the calculation grid of the hull-rudder (end plate) is established during the calculation. The rudder angle of each scheme is 3°. The vortex distribution cloud diagrams of the scheme without end plate and the four schemes with end plate at the propeller disk surface are calculated, as shown in the figure below: Figure 2-Figure 6 As shown in the figure, the original scheme without end plates forms an obvious concentrated vortex in the flow field area inside the propeller, and the vortex intensity is relatively strong, while the four end plate schemes can all suppress the concentrated vortex well, and the vortex intensity is significantly reduced.

[0122] The axial velocity of the original scheme without end plates and the scheme with four end plates at the propeller disk surface is as follows: Figure 7-Figure 12 As shown in the figure, the distribution of circumferential velocity cloud diagram is as follows: Figure 13-Figure 18 As shown, it can be understood that due to the stronger concentrated vortex of the original scheme, the wake peak values ​​of the axial and circumferential velocities are higher, while the four end plate schemes can reduce the wake peak values ​​to varying degrees.

[0123] In order to specifically analyze the impact of the original scheme without end plates and the scheme with four end plates on the internal flow field of the propeller, this embodiment establishes a hull-rudder-propeller overall structure grid for numerical calculation, and analyzes and compares the axial velocity and circumferential velocity distribution curves at different radii of the pump jet flow field at the propeller disc surface. The axial velocity distribution at different radii of the propeller disc surface of each scheme is compared as follows: Figure 17-Figure 25 As shown, the circumferential velocity distribution is compared as shown in 26- Fig.34 shown.

[0124] Embodiment 3:

[0125] This embodiment provides a design system for fixing a fairing plate at the lower end of a rudder of an underwater vehicle, comprising:

[0126] The first module determines the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determines the top view shape and size of the fairing;

[0127] The second module is to establish a three-dimensional model of the underwater vehicle and the rudder, use a computational fluid dynamics method to determine the flow field and streamline shape near the installation position of the fairing, and determine the side shape of the fairing according to the flow field and streamline shape;

[0128] The third module takes the rudder end flow suppression effect as the goal, considers the influence of the fairing on the rudder lift and drag, uses the computational fluid dynamics method to optimize the installation position, top view shape, size and side shape of the fairing, determines the preliminary design scheme of the fairing, and optimizes the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle;

[0129] The fourth module considers the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishes the numerical calculation model of the underwater vehicle, rudder and propeller, evaluates the influence of the propeller on the rectifier, and adjusts the parameters of the rectifier;

[0130] The fifth module is to conduct hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determine the final design of the fairing in combination with the maneuverability, rapidity and stealth indicators.

[0131] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0132] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A design method for fixing a fairing plate at the lower end of a rudder of an underwater vehicle, characterized in that: include: S100, determining the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determining the top view shape and size of the fairing; S200, establishing a three-dimensional model of the underwater navigation body and the rudder, using a computational fluid dynamics method to determine the flow field and streamline shape near the installation position of the fairing, and determining the side shape of the fairing according to the flow field and streamline shape; S300, taking the rudder end flow suppression effect as the goal, considering the influence of the fairing on the rudder lift and drag, using the computational fluid dynamics method to optimize the installation position, top view shape, size and side shape of the fairing, determine the preliminary design scheme of the fairing, and optimize the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle; S400, considering the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishing a numerical calculation model of the underwater vehicle, the rudder and the propeller, evaluating the influence of the propeller on the rectifier, and adjusting the parameters of the rectifier; S500, performing hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determining the final design of the fairing in combination with maneuverability, rapidity and stealth indicators.

2. A design method for fixing a rectifier plate at the lower end of a rudder of an underwater vehicle according to claim 1, characterized in that: Step S100 includes: S101, determining the relative position of the fairing on the navigation body according to the installation position of the rudder and the gap between the fairing and other components of the navigation body, and fine-adjusting the installation position and angle of the fairing according to the flow field characteristics; S102. Determine the top view shape of the rectifier plate according to design requirements, and preliminarily estimate the size of the rectifier plate according to relevant specifications or empirical formulas, and adjust and optimize it in subsequent processes.

3. The design method for fixing the fairing at the lower end of the rudder of an underwater vehicle according to claim 1, characterized in that: Step S200 includes: S201, using three-dimensional modeling software to establish underwater navigation body and rudder models, and meshing the models; S202. Import into professional CFD software, set boundary conditions according to actual working conditions, run CFD simulation, monitor convergence and stability during simulation, and analyze flow field and streamline shape at the installation position of rectifier plate; S203: Determine the side shape of the rectifier plate according to the flow field and streamline shape at the installation position of the rectifier plate.

4. A design method for fixing a rectifier plate at the lower end of a rudder of an underwater vehicle according to claim 3, characterized in that: Step S201 includes: according to the needs of CFD simulation, appropriately simplifying the underwater vehicle and rudder model to remove details that have little effect on fluid flow.

5. A method for designing a fixed fairing plate at the lower end of a rudder of an underwater vehicle according to any one of claims 1 to 4, characterized in that: Step S300 includes: S301, based on experience and preliminary simulation results, design preliminary solutions for rectifiers with various geometric parameters, and evaluate the influence of the rectifiers on the lift and drag of the rudder according to the steps S201 and S202, and after each calculation converges, continuously adjust the rectifier parameters according to the simulation results and seek the best solution; S302. Adjust the parameters of the mother type rectifier plate to check the influence of different parameters on the flow field uniformity of the propeller disc surface, compare the flow field uniformity of the propeller disc surface after the mother type rectifier plate is optimized with the flow field uniformity of the original propeller disc surface, and evaluate the improvement effect.

6. A design method for fixing a rectifier plate at the lower end of a rudder of an underwater vehicle according to claim 5, characterized in that: Step S400 includes: S401, on the basis of step S301, according to the specific parameters and layout of the propeller, add the corresponding propeller to the model, and establish the numerical calculation model of the underwater navigation body, rudder, fairing, and propeller; S402, using a CFD solver to solve the numerical calculation model, obtain detailed flow information of the flow field around the rectifier, analyze the specific impact of the propeller suction effect on the flow field around the rectifier, and evaluate the potential impact of these impacts on the performance of the rectifier; S403. Based on the numerical simulation results, identify the key parameters that have a greater impact on the performance of the rectifier, make preliminary adjustments to the key parameters, re-perform numerical simulation to evaluate the adjustment effect, and perform numerical simulation verification on the optimized rectifier to ensure that it can minimize the impact of the suction effect of the thruster while meeting the design requirements.

7. A fixed straightening plate at the lower end of a rudder of an underwater vehicle, which is realized by applying the design method for fixing the straightening plate at the lower end of a rudder of an underwater vehicle as described in claims 1 to 6, and is characterized in that: It can effectively suppress the flow around the lower end surface of the rudder of the underwater vehicle, reduce the lateral flow of the rudder, and prevent the fluid from flipping over at the rudder end to form a separation vortex when the rudder angle is small; the straightening plate is arranged at the gap between the rear end of the stabilizing wing and the rotating rudder, and is installed on the upper end surface of the stabilizing wing. The plane is perpendicular to the rudder surface, and the side shape is the same as the streamline shape at the installation position.

8. The method for fixing a rectifier plate at the lower end of a rudder of an underwater vehicle according to claim 7, characterized in that: The top view shape of the fairing can be changed accordingly according to the flow field near the rudder.

9. The method for fixing a rectifier plate at the lower end of a rudder of an underwater vehicle according to claim 7, characterized in that: The top view shape of the fairing can adopt a specific airfoil shape or be the same as the rudder wing section to maximize the benefit of the fairing.

10. A design system for fixing a fairing plate at the lower end of a rudder of an underwater vehicle, characterized in that: include: The first module determines the installation position of the fairing according to the installation position of the rudder of the underwater vehicle, and preliminarily determines the top view shape and size of the fairing; The second module is to establish a three-dimensional model of the underwater vehicle and the rudder, use a computational fluid dynamics method to determine the flow field and streamline shape near the installation position of the fairing, and determine the side shape of the fairing according to the flow field and streamline shape; The third module takes the rudder end flow suppression effect as the goal, considers the influence of the fairing on the rudder lift and drag, uses the computational fluid dynamics method to optimize the installation position, top view shape, size and side shape of the fairing, determines the preliminary design scheme of the fairing, and optimizes the fairing parameters with reference to the uniformity of the propeller disk flow field of the underwater vehicle; The fourth module considers the interference of the suction effect of the underwater vehicle propeller on the flow field around the rectifier, establishes the numerical calculation model of the underwater vehicle, rudder and propeller, evaluates the influence of the propeller on the rectifier, and adjusts the parameters of the rectifier; The fifth module is to conduct hydrodynamic analysis on the numerical calculation models of the underwater vehicle, rudder and thruster, and determine the final design of the fairing in combination with the maneuverability, rapidity and stealth indicators.

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