Underwater vehicle structure with low flow radiated noise and design method thereof

Abstract

The application provides a low-flow radiation noise underwater vehicle structure and a design method thereof. The underwater vehicle structure comprises a head part and an extension part, the extension part comprises a parallel middle body and a tail transition part, the parallel middle body refers to a part with the same cross-sectional area and shape of the vehicle body, and the tail transition part refers to a tail gradually contracted from the parallel middle body. The diameter of the head part configuration of the underwater vehicle at 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6 and 6 / 6 times of the head length is 0 times of the diameter, 0.531 times of the diameter, 0.745 times of the diameter, 0.884 times of the diameter, 0.965 times of the diameter, 0.997 times of the diameter and 1.0 times of the diameter respectively. The application obtains a low-flow radiation noise underwater vehicle structure with precision, low cost and high reliability by optimizing the noise design of the underwater vehicle.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicle technology, and more specifically, to an underwater vehicle structure with low flow-radiated noise and its design method. Background Technology

[0002] In the design of underwater vehicles, the vehicle body, with its simple geometry and excellent hydrodynamic characteristics, is widely used in practical engineering. Noise from underwater vehicles significantly impacts their stealth performance. The main noise sources for underwater vehicles include power machinery noise, propeller noise, and hydrodynamic noise. While mechanical and propeller noise have been somewhat controlled, hydrodynamic noise at high speeds has become a significant noise source for researchers. Hydrodynamic noise comprises two parts: direct flow noise and flow-induced structural noise. Direct flow noise refers to the noise generated by fluid pressure pulsations, such as free shear turbulence, boundary layer pulsations, and vortex turbulence. Flow-induced structural noise refers to the noise generated by the interaction between the fluid and the structure, such as the noise caused by fluid pulsations and structural vibrations resulting from fluid-structure interaction.

[0003] Turbulent pulsating pressure on the surface of underwater vehicles serves as the excitation source for underwater noise generation, and is a key issue that must be addressed in the prediction of hydrodynamic noise of underwater vehicles. Affected by the incoming current, the bow of an underwater vehicle comes into intense contact with the current, generating turbulent pulsating pressure near the wall surface, which excites structural vibration and radiates noise. Low-noise design of underwater vehicles relies not only on the bow but also requires an extended configuration to form a complete underwater vehicle design. The extended configuration mainly includes a parallel midbody section and a tail transition section. The parallel midbody refers to the section in the midbody where all cross-sectional areas and shapes are identical, while the tail transition section refers to the section that gradually narrows from the parallel midbody to the tail to ensure stable water flow.

[0004] With the continuous development of computer and simulation technologies, numerical simulation has become an advanced and reliable method for designing underwater vehicles with low hydrodynamic noise. Currently, underwater vehicle hydrodynamic noise design methods mainly rely on physical experimental research and expert experience to design different configurations for optimization. However, existing underwater vehicle structures and their design methods suffer from drawbacks such as long experimental cycles and significant consumption of human and physical resources. Furthermore, existing design methods cannot simultaneously achieve both accuracy and efficiency in numerical simulation, especially in noise prediction, where they cannot perform detailed simulations of the flow field. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide an underwater vehicle structure with low flow radiation noise and its design method. By performing noise optimization design on the underwater vehicle, a precise, low-cost, and highly reliable underwater vehicle structure with low flow radiation noise is obtained.

[0006] To solve the above problems, the technical solution of the present invention is as follows:

[0007] A low-flow-radiated noise underwater vehicle structure includes a bow section and an extension section. The extension section comprises a parallel midbody and a tail transition section. The parallel midbody refers to the portion of the vehicle body in which all cross-sectional areas and shapes are identical. The tail transition section refers to the tail section that gradually tapers from the parallel midbody. The diameters of the bow section at 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6, and 6 / 6 times the bow length are 0 times the diameter, 0.531 times the diameter, 0.745 times the diameter, 0.884 times the diameter, 0.965 times the diameter, 0.997 times the diameter, and 1.0 times the diameter, respectively.

[0008] Preferably, the point values ​​are connected sequentially based on the cubic spline curve method to form the basic spline curve of the underwater vehicle's bow configuration. The formed spline curve is then rotated 360 degrees around the center of the cross-section circle to form the bow configuration of the underwater vehicle with low flow radiation noise.

[0009] Preferably, the extension is constructed on the basis of the formed underwater vehicle bow configuration, and the diameter of the parallel midbody is consistent with the end diameter of the bow configuration to ensure a smooth and tight connection between the bow profile and the parallel midbody profile.

[0010] Preferably, the length-to-width ratio of the bow configuration of the underwater vehicle is set to 1.5.

[0011] Preferably, the wall-modeled large eddy simulation method is used to calculate the flow radiation noise of the bow of the aircraft with different hull shapes.

[0012] Furthermore, the present invention also provides a design method for an underwater vehicle structure with low flow-radiated noise, comprising the following steps:

[0013] Select the deformation parameters for the bow configuration of the underwater vehicle;

[0014] The bow of an underwater vehicle was modeled and reconstructed using a free deformation method.

[0015] The wall-modeled large eddy simulation method was used to numerically simulate underwater vehicles with different bow configurations, and far-field radiated noise data of underwater vehicles with different bow configurations were obtained.

[0016] The Kriging model was used to construct an approximate model, and the functional mapping relationship between the bow line parameters and the bow flow radiation noise of different underwater vehicles was obtained. An approximate model between the bow deformation parameters and the far-field radiation noise of the underwater vehicle was constructed.

[0017] Using a non-gradient genetic algorithm, the lowest far-field radiation noise value and the corresponding deformation control parameters are found in the Kriging model to obtain the bow configuration of the underwater vehicle with low flow radiation noise.

[0018] Preferably, the aspect ratio of the bow configuration of the constructed low-flow-radiated noise underwater vehicle is 1.5.

[0019] Preferably, the diameters of the bow configuration of the constructed low-flow-radiated-noise underwater vehicle at bow lengths of 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6, and 6 / 6 times the bow length are 0 times the diameter, 0.531 times the diameter, 0.745 times the diameter, 0.884 times the diameter, 0.965 times the diameter, 0.997 times the diameter, and 1.0 times the diameter, respectively.

[0020] Preferably, an extension portion is constructed on the basis of the bow configuration of the underwater vehicle. The extension portion includes a parallel midbody and a tail transition portion. The diameter of the parallel midbody is consistent with the end diameter of the bow configuration to ensure a smooth and tight connection between the bow profile and the parallel midbody profile.

[0021] Compared with existing technologies, this invention proposes a low-flow-radiated noise underwater vehicle bow configuration and establishes a set of efficient and precise optimization design methods for low-flow-noise bow configurations. Compared with traditional short-axis, wide-bodied bow configurations, the underwater vehicle bow configuration obtained by the optimization design method of this invention can effectively reduce the far-field radiated noise generated during underwater vehicle navigation. At the same time, the reduced curved surface area of ​​the underwater vehicle bow effectively reduces production costs and improves production efficiency. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 This is a structural diagram of the underwater vehicle body with low flow-radiated noise according to the present invention;

[0024] Figure 2 This is a curve showing the bow configuration of the low-flow-radiated noise underwater vehicle according to the present invention.

[0025] Figure 3 This is a curve showing the overall shape of the low-flow-radiated noise underwater vehicle of the present invention.

[0026] Figure 4 These are cross-sectional dimensions of the bow configuration of the low-flow-radiated-noise underwater vehicle of the present invention;

[0027] Figure 5 This is a flowchart illustrating the design method for a low-flow-radiated noise underwater vehicle structure according to the present invention.

[0028] Figure 6 This is a detailed flowchart of the design method for the low-flow-radiated noise underwater vehicle structure of the present invention;

[0029] Figure 7 This is a design drawing of the lattice deformation frame at the bow of the underwater vehicle of the present invention;

[0030] Figure 8 This is a flowchart of the non-gradient genetic algorithm of the present invention;

[0031] Figure 9 These are structural diagrams of two underwater vehicle models;

[0032] Figure 10 Setting up the computational domain for wall-modeled large eddy simulation;

[0033] Figure 11 Mesh generation diagram at the boundary of the wall-modeled large eddy simulation calculation;

[0034] Figure 12 A comparison diagram of the profiles of the short-axis fat front configuration and the low-flow-radiated-noise front configuration of the present invention;

[0035] Figure 13 A diagram showing the vortex structure distribution of the short-axis fat head configuration;

[0036] Figure 14 This is a diagram showing the vortex structure distribution of the low-flow-radiated noise head configuration of the present invention.

[0037] Figure 15 This is a longitudinal section diagram of the pressure distribution in a short-axis, obese head configuration.

[0038] Figure 16 This is a longitudinal section pressure distribution diagram of the low-flow radiation noise head configuration of the present invention;

[0039] Figure 17 This is a surface pressure distribution diagram for a short-axis, obese head configuration.

[0040] Figure 18 This is a surface pressure distribution diagram of the low-flow radiation noise head configuration of the present invention;

[0041] Figure 19 The image shows a comparison of the far-field radiated noise octave spectrum between the short-axis fat head configuration and the low-flow radiated noise head configuration of this invention. Detailed Implementation

[0042] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0043] Specifically, the present invention provides an underwater vehicle structure with low flow-radiated noise, such as... Figure 1 As shown, the underwater vehicle structure with low flow radiation noise includes a bow section 1 and an extension section. The extension section includes a parallel midbody 2 and a tail transition section 3. The parallel midbody 2 refers to the part of the midbody where all cross-sectional areas and shapes are the same. The tail transition section 3 refers to the part that gradually narrows from the parallel midbody to the tail to ensure stable water flow.

[0044] In this embodiment, the shape points are connected sequentially based on the cubic spline curve method to form the basic spline curve of the bow shape of the underwater vehicle, such as... Figure 2 As shown. The spline curve formed is rotated 360 degrees around the center of the circular cross-section to create the three-dimensional configuration of the low-flow-radiated noise bow of the three-dimensional underwater vehicle. Further, as... Figure 3 As shown, an extension is constructed on the basis of the formed three-dimensional underwater vehicle bow configuration, including the parallel midbody and the tail transition section. The diameter of the parallel midbody is consistent with the diameter of the end of the bow profile of the rotating body to ensure a smooth and tight connection between the bow profile and the parallel midbody profile.

[0045] In this embodiment, the bow profile of the underwater vehicle is reconstructed, with a length-to-width ratio of 1.5. The diameters of the bow profile at 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6, and 6 / 6 times the bow length are 0 times the diameter, 0.531 times the diameter, 0.745 times the diameter, 0.884 times the diameter, 0.965 times the diameter, 0.997 times the diameter, and 1.0 times the diameter, respectively. Figure 4 As shown, an underwater vehicle structure with low flow-radiated noise can be obtained by improving the bow shape of the vehicle.

[0046] In an alternative embodiment, the bow profile is reconstructed using a free deformation method to form bow profiles of different shapes.

[0047] Furthermore, the wall-modeled large eddy simulation method can be used to calculate the flow-radiated noise at the bow of a vehicle with different hull shapes.

[0048] Compared to the existing short-axis, thick-bodied underwater vehicle bow configuration, the bow configuration of this invention can reduce far-field radiated noise by up to 3 dB. Furthermore, the smoother the curvature transition of the bow configuration of this invention, the more stable the water flow at the bow will be, making it less likely for the flow transition at the bow of the rotating body to occur prematurely. Premature flow transition will lead to turbulent flow after the transition point, larger wall pressure pulsation amplitude, and higher wall pressure pulsation vibration frequency, thus making the high-frequency vibration and the resulting flow radiated noise more significant.

[0049] The bow configuration designed in this invention, with its gentle curvature transition, can effectively delay the transition of water flow at the bow of the vehicle, i.e., delay the transition. As a result, the laminar flow region in the bow area expands, the flow inside the laminar flow region is stable, the amplitude of the wall pressure pulsation is very low and the frequency is weak. Therefore, the pressure pulsation in the laminar flow region is very small, and the resulting far-field radiation noise is also much smaller.

[0050] Furthermore, the present invention also provides a design method for an underwater vehicle structure with low flow-radiated noise, such as... Figure 5 and Figure 6 As shown, the method includes the following steps:

[0051] S1: Select the deformation parameters for the bow configuration of the underwater vehicle;

[0052] Specifically, the deformation parameters of the underwater vehicle's bow configuration are first selected, the number of control parameters is determined, and the deformation parameters are sampled.

[0053] S2: The bow of the underwater vehicle is modeled and reconstructed using the free deformation method;

[0054] Specifically, such as Figure 7 As shown, the underwater vehicle's bow is modeled and reconstructed using the free deformation method (FFD) to obtain the desired configuration. Multiple different bow configurations are selected to build a model database.

[0055] S3: The wall-modeled large eddy simulation method was used to perform numerical simulations on underwater vehicles with different bow configurations to obtain far-field radiated noise data of underwater vehicles with different bow configurations.

[0056] Specifically, the Wall Modeled Large Eddy Simulation (WMLES) method was used to perform refined numerical simulations of underwater vehicles with different bow configurations, and the flow radiation noise of the bow of underwater vehicles with different bow configurations was calculated.

[0057] S4: Using the Kriging model to construct an approximate model, the functional mapping relationship between the bow shape parameters and the bow flow radiation noise of different underwater vehicles is obtained, and an approximate model between the bow deformation parameters and the far-field radiation noise of the underwater vehicle is constructed.

[0058] S5: Using a non-gradient genetic algorithm, the lowest far-field radiation noise value and the corresponding deformation control parameters are found in the Kriging model to obtain the bow configuration of the underwater vehicle with low flow radiation noise.

[0059] Specifically, such as Figure 8 As shown, a non-gradient genetic algorithm is used to find the lowest far-field radiated noise value and the corresponding deformation control parameters in the Kriging model, ultimately obtaining the bow configuration of the underwater vehicle with low flow radiated noise. In this embodiment, the aspect ratio of the constructed bow configuration with low flow radiated noise is 1.5, and the diameters of the bow linear portion at 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6, and 6 / 6 times the bow length are 0 times the diameter, 0.531 times the diameter, 0.745 times the diameter, 0.884 times the diameter, 0.965 times the diameter, 0.997 times the diameter, and 1.0 times the diameter, respectively.

[0060] Furthermore, an extension is constructed on the basis of the formed underwater vehicle bow configuration, including the parallel midbody and the tail transition section. The diameter of the parallel midbody is consistent with the diameter of the end of the bow profile of the rotating body, so as to ensure a smooth and tight connection between the bow profile and the parallel midbody profile.

[0061] Numerical Verification and Result Analysis of Bow Configuration for Underwater Vehicles with Low Flow Radiation Noise

[0062] This invention provides numerical verification and result analysis of the bow configuration of the underwater vehicle with low flow radiation noise through a specific embodiment. A schematic diagram of the underwater vehicle model used in this embodiment is shown below. Figure 9 As shown, the diameter D of the parallel central body is 2m, and the total length L is 16m. A schematic diagram of the computational domain used in this embodiment is shown below. Figure 10 As shown, the computational domain inlet is located at a distance of twice the length of the hull from the bow, the computational domain outlet is located at a distance of five times the length of the hull from the stern, and the perimeter of the computational domain is located at a distance of twice the length of the hull from the centerline. A schematic diagram of the near-wall computational mesh used in this embodiment is shown below. Figure 11 As shown, 30 mesh layers are arranged within the boundary layer thickness δ, with a growth rate of 1.01, and a total mesh count of 3.1 × 10⁷. In the wall stress model settings, the sampling height h is set to the center of the third mesh layer near the wall.

[0063] Figure 12 The image shows a comparison between the original and optimized line shapes obtained through numerical optimization. The optimized line shapes are more streamlined. Figure 13 and Figure 14The comparison diagram of the vortex structure before and after optimization shows that the flow transition is delayed. The vortex structure reflects the degree of turbulence in the flow field. The pressure pulsation amplitude is small in the laminar flow region, which is not conducive to the generation and propagation of flow noise. Therefore, the larger the laminar flow region, the smaller the far-field radiated noise generated by pressure pulsation at the bow of the underwater vehicle. It can be seen from the figure that the laminar flow region of the low-flow-radiated-noise bow is significantly larger than that of the original configuration. This shows that the delay in flow transition is helpful in designing a low-flow-radiated-noise bow configuration. Figure 15 , Figure 16 , Figure 17 and Figure 18 As shown in the pressure distribution of the airframe, the pressure field distribution reveals that a reduced pressure gradient is beneficial for stable flow development and delays the generation and development of turbulence. The nose configuration with low flow radiation noise exhibits smaller pressure gradient changes, thus demonstrating better flow stability. Figure 19 The demonstration of sound pressure optimization for the aircraft shows that the reduction in long-range radiated noise at 20m can be around 3dB.

[0064] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A structure for an underwater vehicle with low flowing noise radiation, characterized in that, The underwater vehicle structure includes a bow and an extension. The extension comprises a parallel midbody and a tail transition section. The parallel midbody refers to the portion of the vehicle body where all cross-sectional areas and shapes are identical. The tail transition section refers to the tail that gradually tapers from the parallel midbody. The diameters of the bow configuration at 0 / 6, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6, and 6 / 6 times the bow length are 0 times the diameter, 0.531 times the diameter, 0.745 times the diameter, 0.884 times the diameter, and 0... The diameters are 0.965 times, 0.997 times, and 1.0 times. Based on the cubic spline curve method, the shape value points are connected sequentially to form the basic spline curve of the underwater vehicle's bow configuration. The formed spline curve is rotated 360 degrees around the center of the cross-section circle to form the underwater vehicle's bow configuration with low flow radiation noise. The extension part is constructed on the basis of the formed underwater vehicle's bow configuration. The diameter of the parallel midbody is consistent with the end diameter of the bow configuration to ensure a smooth and tight connection between the bow line and the parallel midbody line.

2. The underwater vehicle structure with low flow-radiated noise according to claim 1, characterized in that, The length-to-maximum-diameter ratio of the bow configuration of the underwater vehicle is set to 1.

5.

3. A design method for an underwater vehicle structure with low flow-radiated noise as described in any one of claims 1-2, characterized in that, The method includes the following steps: Select the deformation parameters for the bow configuration of the underwater vehicle; The bow of an underwater vehicle was modeled and reconstructed using a free deformation method. The wall-modeled large eddy simulation method was used to numerically simulate underwater vehicles with different bow configurations, and far-field radiated noise data of underwater vehicles with different bow configurations were obtained. The Kriging model was used to construct an approximate model, and the functional mapping relationship between the bow line parameters and the bow flow radiation noise of different underwater vehicles was obtained. An approximate model between the bow deformation parameters and the far-field radiation noise of the underwater vehicle was constructed. Using a non-gradient genetic algorithm, the lowest far-field radiation noise value and the corresponding deformation control parameters are found in the Kriging model to obtain the bow configuration of the underwater vehicle with low flow radiation noise.

Images