Design method of underwater vehicle model and underwater vehicle model

Abstract

A design method for an underwater vehicle model and the underwater vehicle model itself. The model includes a base and a detachable part. The total mass of the base is M. b The detachable part has a length of L along the model axis. a The detachable part includes multiple layers of mass blocks arranged along the model's axis. The model has j target working conditions, M. j * x cj * I yj * Let M represent the total target mass, the target axial center of mass, and the target pitch axis moment of inertia for the j-th working condition, respectively. j * All are equal; determine the number of mass block layers N; establish the X-axis with the model axis: the mass of the base part is M. b The axial centroid coordinate of the foundation is x. b The moment of inertia about its own center of mass and about the pitch axis is I. yb,c The center coordinate of the mass block in the first layer is x. s The center coordinates of the mass block in the kth layer are x k k = natural numbers from 1 to N; establish a set of equations for the target working conditions of the model; use trial calculations to determine the mass distribution of each working condition mass block, so as to facilitate the rapid and accurate switching of the working conditions of the test model.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicle testing technology, and in particular to a design method for an underwater vehicle model and an underwater vehicle model. Background Technology

[0002] When conducting underwater tests on underwater vehicles, it is usually necessary to set different test conditions for underwater performance tests on vehicle models of the same specifications and mass. That is, different axial center of mass and target pitch axis rotation inertia need to be set under different working conditions.

[0003] The usual method is to adjust the test conditions by changing the counterweight inside the model of the aircraft, but this method requires repeated disassembly and reassembly of the model, which is cumbersome. Alternatively, the method of changing the counterweight outside the model of the aircraft can not quickly and accurately switch the test conditions.

[0004] Therefore, a new design method and model for underwater vehicles are needed to facilitate rapid and accurate switching of operating conditions for the test model. Summary of the Invention

[0005] To address the shortcomings of the prior art, the applicant provides a design method and model for an underwater vehicle, thereby facilitating rapid and accurate switching of the operating conditions of the test model.

[0006] The technical solution adopted in this invention is as follows: A design method for an underwater vehicle model, wherein the underwater vehicle model is cylindrical; Step 1: Model Structure Design: The model includes a base and a detachable part. The total mass of the base is M. b The length of the detachable part along the model axis is L. a , The detachable part includes multiple layers of mass blocks arranged along the model's axis. Each layer of mass blocks has the same structural dimensions. After all mass blocks are assembled with the base part, the external structure of the base part and the mass blocks forms the streamlined outer surface of the model. The model has j target operating conditions, M. j * x cj * I yj * Let M represent the total target mass, the target axial center of mass, and the target pitch axis moment of inertia for the j-th working condition, respectively. j * All are equal; Step 2: Determine the number of layers N of the mass block; Step 3: Establish the X-axis using the model's axis: The mass of the foundation is M.b The axial centroid coordinate of the foundation is x. b The moment of inertia of the base relative to its own center of mass about the pitch axis is I. yb,c The center coordinate of the mass block in the first layer is x. s The center coordinates of the mass block in the kth layer are x k k = natural numbers from 1 to N; Step 4: Establish the model's target operating condition equations: M j * = M b + Σ k=1 N m jk M j * x cj * = M b x b + Σ k=1 N m jk x k I yj * = I yb,c + M b (x b - x cj * ) 2 + Σ k=1 N [I yk,c + m jk (x k - x cj * ) 2 ] h = L a / N x k = x s + (k - 1)h Where, m jk Let I be the mass of the k-th mass block in the j-th working condition. yk,c Let be the moment of inertia of the k-th mass block relative to its own center of mass and about the pitch axis in the j-th working condition; Step 5: Determine the mass distribution pattern of the mass block: The mass of the mass block at different positions under each working condition is determined by trial calculation. The design values ​​of the total mass, axial center of mass and pitch axis rotational inertia of each working condition are made to meet the requirements of the deviations from the target total mass, target axial center of mass and target pitch axis rotational inertia. If the requirements are not met, the amount of N is increased and steps three to five are repeated.

[0007] As a further improvement to the above technical solution: N is an integer greater than or equal to six.

[0008] The equivalent cross-sectional area of ​​each mass block perpendicular to the model axis is A; The volume V of each layer of mass blocks k =A×h; The total number of mass blocks forming models under different working conditions is N. All mass blocks have two density specifications, denoted as low density and high density, with the low density value being ρ. L The value of high density is ρ H ; Define the layout variable for the k-th layer in the j-th working condition as: b jk ∈ {0, 1}, where 0 indicates that the k-th layer uses low density and 1 indicates that the k-th layer uses high density; The density of the k-th layer under the j-th working condition is ρ jk = ρ L + b jk (ρ H - ρ L ); Then m jk = ρ jk V k ; The steps for determining the mass of each mass block under each working condition using a trial-and-error method include: S1. Establish mass block density layout variables: Determine the number of high-density mass blocks to be used as q, where q is less than N, and establish candidate layout variables for each working condition. Define the candidate layout vector for the j-th working condition as B. j =[b j,1 b j,2 , ..., b j,N Given the current N and q, generate a generator that satisfies Σb j,k =q all candidate arrangement vectors B j ; S2. Determine the layout vector obtained from the screening of standard working conditions: For the candidate layout vector B1 for each case in the standard working conditions, based on the target total mass M1 of the standard working conditions... * Establish about ρ L and ρ H The mass equation is based on the target axial centroid x under standard working conditions. c,1 *Establish about ρ L and ρ H The axial centroid equation is obtained by simultaneously solving the mass equation and the axial centroid equation to obtain the low-density ρ. L and high density ρ H Then calculate the corresponding pitch axis moment of inertia I. y,1 and I y,1 With target value I y,1 * Compare the layout vectors and select all layout vectors whose deviations meet the requirements. If no layout vectors meet the requirements, increase q and repeat steps S1-S2. If no layout vectors meet the requirements, increase N and repeat steps two to five. S3. Determine the density ρ L and high density ρ H Select one of the layout vectors obtained in step S2, and select the density ρ corresponding to the layout vector. L and high density ρ H ; S4: Two-level layout vector selection determines the layout vector B for other target working conditions. j Fix the current N, q, ρ L and ρ H For all candidate layout vectors B for other target working conditions j Calculate the corresponding axial centroid x c,j and the target axial centroid x c,j * By comparing and filtering, preliminary arrangement vectors that meet the preset deviation requirements are obtained. Then, the pitch axis moment of inertia I is calculated for all the preliminary selected arrangement vectors. y,j and the moment of inertia I relative to the target pitch axis y,j * Compare; If a final arrangement vector that meets the preset deviation requirements can be obtained through filtering, then an arrangement vector is selected from the final arrangement vectors. If the final arrangement vector that meets the preset deviation requirements cannot be obtained through screening, and the arrangement obtained from the standard working condition determined in step S2 is multiple, repeat step S3 to select a new arrangement vector and then proceed to step S4. If the current N, q, and ρ are fixed L and ρ H For all candidate layout vectors B for other target working conditions j The axial centroid x is used for calculation c,j The target requirement is not met, or the calculated pitch axis moment of inertia I y,jIf the requirements are not met, increase q and repeat steps S1-S4. If there is still no feasible solution, increase N and repeat steps two to five. S5: Determine the mass block distribution for all operating conditions: The distribution of the mass blocks in the standard operating condition is determined based on the arrangement vector selected in S3. The distribution of mass blocks for other working conditions is determined based on the arrangement vector selected in step S4.

[0009] The installation locations of all mass blocks are evenly divided from the bow to the stern into three equal adjustment zones: the front adjustment zone, the middle adjustment zone, and the rear adjustment zone. The number of mass blocks in each of the front, middle, and rear adjustment zones is greater than or equal to two. The model with high-density mass blocks located in the middle adjustment zone is used as the model for the standard working condition.

[0010] In the model structure design steps: First, determine the total buoyancy based on the target shape and displacement volume of the model, and then determine the target total mass M of the model based on the target net buoyancy. j * .

[0011] In the model structure design steps: Design the structure of the foundation based on the devices to be installed inside the model, and determine the mass M of the foundation. b The axial centroid coordinate of the foundation is x. b The moment of inertia of the base relative to its own center of mass about the pitch axis is I. yb,c .

[0012] The basic component includes a bow structure, a stern structure, and a central connecting structure. The central connecting structure is rod-shaped, with one end connected to the bow structure and the other end connected to the stern structure. The structure of each layer of mass block includes a first half-ring and a second half-ring, which are fixedly connected to the central connecting structure.

[0013] The inner ring of the first half-ring is provided with a first limiting surface, and the inner ring of the second half-ring is provided with a second limiting surface. Both the first limiting surface and the second limiting surface are in contact with the central connecting structure, which are used to restrict the degrees of freedom of the mass block and the central connecting structure in the direction around the model axis.

[0014] The first half-ring is provided with a first bolt hole, and the second half-ring is provided with a second bolt hole. When the first half-ring and the second half-ring are fixedly connected to the central connecting structure, the first bolt hole and the second bolt hole are aligned, and a set of fastening components are simultaneously inserted into the first bolt hole and the second bolt hole.

[0015] An underwater vehicle model is designed using any of the design methods described above.

[0016] The beneficial effects of this invention are as follows: This invention divides the model into a basic part and a detachable part composed of an equal number of mass blocks. By allocating the mass of the mass blocks at different locations, models with different mass distributions are obtained. Different assembly methods can be selected before the test according to different working conditions, which facilitates the rapid and accurate switching of the working conditions of the test model.

[0017] Furthermore, the present invention also has the following advantages: (1) The design method of the underwater vehicle model in this embodiment combines known conditions with the position assumption of high-density mass blocks, converts continuous density value variables into discrete values ​​and performs trial calculations. Two density specifications are used to achieve the main target parameter allocation. The axial layer number, layer center coordinates, module volume, density specifications and arrangement variables are used as designable parameters. The density combination of each layer is calculated based on the total mass of the target, the axial center of mass of the target and the moment of inertia of the target pitch axis. The combination of two densities and N mass blocks is designed to facilitate cost and inventory control, while taking into account adjustment accuracy, processing cycle and assembly efficiency.

[0018] (2) Two semi-rings are connected to the foundation in a radially opposite manner along the model. When adjusting different working parameters, the underwater model can be quickly and accurately adjusted and safely fixed, solving the problem of inconvenience in adjusting the mass and disassembling the model shell. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the underwater vehicle model of the present invention.

[0020] Figure 2 This is an exploded view of the underwater vehicle model of the present invention.

[0021] Figure 3 This is a cross-sectional view of the underwater vehicle model of the present invention.

[0022] Figure 4 This is the front view of the underwater vehicle model of the present invention.

[0023] The components include: 1. Foundation; 11. Bow structure; 12. Central connecting structure; 13. Stern structure. 2. Detachable part; 21. Mass block; 211. First half ring; 212. Second half ring; 213. First bolt hole; 214. Second bolt hole. Detailed Implementation

[0024] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] Example 1: The design method of the underwater vehicle model in this embodiment is as follows: Figures 1-4 As shown, the underwater vehicle model is cylindrical; Step 1: Model Structure Design: The model consists of a base part 1 and a detachable part 2. The total mass of the base part 1 is M. b The length of the detachable part 2 along the model axis is L. a , The detachable part 2 includes multiple layers of mass blocks 21 arranged along the model's axial direction. Each layer of mass blocks 21 has the same structural dimensions. After all mass blocks 21 are assembled with the base part 1, the external structure of the base part 1 and the mass blocks 21 forms the streamlined outer surface of the model. The model has j target operating conditions and M j * x cj * I yj * Let M represent the total target mass, the target axial center of mass, and the target pitch axis moment of inertia for the j-th working condition, respectively. j * All are equal; Step 2: Determine the number of layers N of mass block 21; Step 3: Establish the X-axis based on the model's axis lines (e.g., ... Figure 4 As shown): The mass of the basic part 1 is M. b The axial centroid coordinate of foundation part 1 is x b The moment of inertia of the basic part 1 relative to its own center of mass and about the pitch axis is I. yb,c The center coordinate of mass block 21 in layer 1 is x s The center coordinates of mass block 21 in the kth layer are x k k = natural numbers from 1 to N; Step 4: Establish the model's target operating condition equations: M j * = M b + Σ k=1 N m jk (For the mass equation) M j * x cj * = M b x b + Σ k=1 N m jk x k (Equation for the axial centroid) I yj *= I yb,c + M b (x b - x cj * ) 2 + Σ k=1 N [I yk,c + m jk (x k - x cj * ) 2 (Equation for moment of inertia of the pitch axis) h = L a / N x k = x s + (k - 1)h Where, m jk For the mass of the k-th mass block 21 in the j-th working condition, I yk,c Let be the moment of inertia of the k-th mass block 21 relative to its own center of mass and about the pitch axis in the j-th working condition; Step 5: Determine the mass distribution pattern of mass block 21: The mass of mass block 21 at different positions under each working condition is determined by trial calculation. The design values ​​of total mass, axial center of mass and pitch axis rotational inertia of each working condition are made to meet the requirements of the deviation between the target total mass, target axial center of mass and target pitch axis rotational inertia. If the requirements are not met, the amount of N is increased and steps three to five are repeated.

[0026] Specifically, N is the number of all mass blocks 21 that can be assembled into different working condition models.

[0027] Specifically, the detachable part 2 is cylindrical, the density of each mass block 21 is uniform, and the shape of the mass block 21 is consistent with the shape of the corresponding position of the model. This simplifies the shell structure of the model. When the mass distribution of the model needs to be adjusted, the distribution of the mass blocks 21 can be adjusted directly. When the target parameters change, the order of the mass blocks 21 along the model axis can be rearranged without redesigning the shape of the model and the installation interface.

[0028] Unlike existing technologies that adjust the mass of a model by using internal or external counterweights, this embodiment couples the mass adjustment scheme with the model structure design during the model design process, making the mass adjustment of the model quick and accurate during testing.

[0029] In general, the various operating conditions of a flight body model refer to the forward and backward changes in the position of the center of mass and the changes in the moment of inertia about the pitch axis. As shown in Table 1, operating condition 1 is the standard operating condition, operating condition 2 is the operating condition in which the center of mass is adjusted forward, and operating condition 3 is the operating condition in which the moment of inertia increases (mass distribution is biased towards both ends).

[0030] The underwater vehicle model design method of this embodiment is used to design the mass distribution scheme of mass blocks 21 for different working conditions, and manufacture the components (basic part 1 and all mass blocks 21) required for assembling the model. Before the start of the test for each working condition, the model with total mass, axial center of mass and pitch axis rotational inertia that meet the requirements of the test working conditions is assembled.

[0031] The underwater vehicle model design method of this embodiment divides the model into a basic part 1 and a detachable part 2 composed of the same number of mass blocks 21. By distributing the mass of the mass blocks 21 at different positions, models with different mass distributions are obtained. Different assembly methods are selected before the test according to different working conditions, which facilitates the rapid and accurate switching of the working conditions of the test model.

[0032] In this embodiment, N is an integer greater than or equal to six.

[0033] The number of layers N of mass block 21 is determined comprehensively based on the target parameter adjustment accuracy, mass block placement capability, and processing, assembly, and inventory management requirements. Different values ​​of N correspond to different axial layer numbers and selectable placement positions, thus affecting the model's axial center of mass and pitch axis rotational inertia adjustment capability.

[0034] Typically, when N=4, there are too few positions to simultaneously form front, middle, and rear layouts; when N=5, the adjustability is improved, but the inertia distinction between the middle and end layouts is not clear enough; when N=6, three clear layouts (middle, front, and end) can be formed, and the number of layers is still relatively small, which facilitates assembly and inventory management; when N=7, processing, numbering, assembly, and inventory management become more complex. Generally, N=6 is the first choice.

[0035] When the accuracy requirements of the target parameters are high (i.e., when the design values ​​of the total mass, axial center of mass, and pitch axis moment of inertia for each working condition are small compared with the required values ​​of the target total mass, target axial center of mass, and target pitch axis moment of inertia), the number of N can be increased.

[0036] Example 2: Based on Example 1, the design method of the underwater vehicle model in this example is as follows: The equivalent cross-sectional area of ​​each layer of mass block 21 perpendicular to the model axis is A; The volume V of each layer of mass block 21 k =A×h; The total number of mass blocks 21 forming models under different working conditions is N. All mass blocks 21 have two density specifications, denoted as low density and high density, with the low density value being ρ. L The value of high density is ρ H ; Define the layout variable for the k-th layer in the j-th working condition as: b jk ∈ {0, 1}, where 0 indicates that the k-th layer uses low density and 1 indicates that the k-th layer uses high density; The density of the k-th layer under the j-th working condition is ρ jk = ρ L + b jk (ρ H - ρ L ); Then m jk = ρ jk V k ; The steps for determining the mass of each mass block 21 under each working condition using a trial-and-error method include: S1. Establish density arrangement variables for mass blocks 21: Determine the number of high-density mass blocks 21 to be q, where q is less than N, and establish candidate arrangement variables for each working condition. Define the candidate arrangement vector for the j-th working condition as B. j =[b j,1 b j,2 , ..., b j,N Given the current N and q, generate a generator that satisfies Σb j,k =q all candidate arrangement vectors B j ; The candidate arrangement vector generated in step S1 is B j =[b j,1 b j,2 , ..., b j,N ], for B1=[b 1,1 b 1,2 , ..., b 1,N In terms of quantity, there are multiple B1s.

[0037] Specifically, the number q of candidate high-density mass blocks 21 can be calculated starting from q=2, and candidate arrangement methods can be generated under the current q. If the requirements are not met, q can be gradually increased. When a symmetrical arrangement is required, an even number of q is preferred.

[0038] S2. Determine the layout vector obtained from the screening of standard working conditions: For the candidate layout vector B1 for each case in the standard working conditions, based on the target total mass M1 of the standard working conditions... * Establish about ρ L and ρ H The mass equation is based on the target axial centroid x under standard working conditions. c,1* Establish about ρ L and ρ H The axial centroid equation is obtained by simultaneously solving the mass equation and the axial centroid equation to obtain the low-density ρ. L and high density ρ H Then calculate the corresponding pitch axis moment of inertia I. y,1 and I y,1 With target value I y,1 * Compare the layout vectors and select all layout vectors whose deviations meet the requirements. If no layout vectors meet the requirements, increase q and repeat steps S1-S2. If no layout vectors meet the requirements, increase N and repeat steps two to five. In step S2, the standard working condition is used as the reference working condition. The standard working condition refers to the working condition in which the target centroid is located at the middle position of the model length direction. The layout vector obtained by screening may have one or more cases. The trial calculation method in this embodiment can be run in a computer.

[0039] S3. Determine the density ρ L and high density ρ H Select one of the layout vectors obtained in step S2, and select the density ρ corresponding to the layout vector. L and high density ρ H ; Specifically, in standard operating conditions, first determine the target axial centroid x c,1 * When selecting the arrangement vector, priority is given to arranging high-density mass blocks 21 close to the target's center of mass with a relatively central mass distribution; then, based on the target's pitch axis moment of inertia I... y,1 * Further select the arrangement vector, and ρ L ρ H Meets material, processing, and assembly requirements.

[0040] S4: Two-level layout vector selection determines the layout vector B for other target working conditions. j Fix the current N, q, ρ L and ρ H For all candidate layout vectors B for other target working conditions j Calculate the corresponding axial centroid x c,j and the target axial centroid x c,j * By comparing and filtering, preliminary arrangement vectors that meet the preset deviation requirements are obtained. Then, the pitch axis moment of inertia I is calculated for all the preliminary selected arrangement vectors. y,j and the moment of inertia I relative to the target pitch axis y,j* Compare; If a final arrangement vector that meets the preset deviation requirements can be obtained through filtering, then an arrangement vector is selected from the final arrangement vectors. If the final arrangement vector that meets the preset deviation requirements cannot be obtained through screening, and the arrangement obtained from the standard working condition determined in step S2 is multiple, repeat step S3 to select a new arrangement vector and then proceed to step S4. If the current N, q, and ρ are fixed L and ρ H For all candidate layout vectors B for other target working conditions j The axial centroid x is used for calculation c,j The target requirement is not met, or the calculated pitch axis moment of inertia I y,j If the requirements are not met, increase q and repeat steps S1-S4. If there is still no feasible solution, increase N and repeat steps two to five. S5: Determine the mass block distribution for all operating conditions: The distribution of mass block 21 in the standard working condition is determined based on the arrangement vector selected in S3; The distribution pattern of mass blocks 21 for other working conditions is determined based on the arrangement vector selected in step S4.

[0041] The final output can be the number of layers N of mass block 21, the number q of high-density mass blocks 21, and the number of low-density mass blocks ρ. L High density ρ H And the layout vector corresponding to each target working condition, and based on ρ L ρ H V k and b j,k Determine the mass m of the k-th layer mass block in the j-th working condition. j,k .

[0042] Specifically, the total number of mass blocks 21 forming models under different working conditions is N, that is, the total number of mass blocks 21 in stock is N. The switching of models under different working conditions is achieved by changing the installation position of mass blocks 21 with different densities. q is an even number and can be evenly divided into front and back. The front, middle and back parts are adjusted according to the order of mass blocks 21. Specifically, we can start with q=2 and conduct trial calculations.

[0043] The above trial calculation method, with a fixed N, first traverses the arrangement of q and the high-density mass block 21; if the deviation requirement is still not met after the traversal is completed, N is increased and the above trial calculation is repeated.

[0044] The design method of the underwater vehicle model in this embodiment combines known conditions with the positional assumptions of the high-density mass block 21. After converting the continuous density value variable into discrete values, trial calculations are performed. Two density specifications are used to achieve the allocation of the main target parameters. The axial layer number, layer center coordinates, module volume, density specification and arrangement variables are used as designable parameters. The density combination of each layer is calculated and determined based on the total mass of the target, the axial center of mass of the target and the moment of inertia of the target pitch axis. The design of the combination of two densities and N mass blocks 21 facilitates the control of cost and inventory quantity, and takes into account the adjustment accuracy, processing cycle and assembly efficiency.

[0045] Example 3: In the design method of the underwater vehicle model in this embodiment, the installation positions of all mass blocks 21 are evenly divided from the bow to the stern into a forward adjustment zone A, a mid-section adjustment zone B, and a rear-end adjustment zone C. The number of mass blocks 21 in the forward adjustment zone A, the mid-section adjustment zone B, and the rear-end adjustment zone C is greater than or equal to two. The model with high-density mass blocks 21 located in the mid-section adjustment zone B is used as the model under standard working conditions, which facilitates the adjustment and repositioning of the mass blocks 21.

[0046] In the model structure design steps: First, determine the total buoyancy based on the target shape and displacement volume of the model, and then determine the target total mass M of the model based on the target net buoyancy. j * .

[0047] In the model structure design steps: Design the structure of the foundation part 1 based on the devices that need to be installed inside the model, and determine the mass M of the foundation part 1. b The axial centroid coordinate of foundation part 1 is x b The moment of inertia of the basic part 1 relative to its own center of mass and about the pitch axis is I. yb,c .

[0048] Regarding the specific assembly structure design of the mass block 21, the basic part 1 of this embodiment includes a bow structure 11, a stern structure 13 and a central connecting structure 12. The central connecting structure 12 is rod-shaped, with one end connected to the bow structure 11 and the other end connected to the stern structure 13. The structure of each layer of mass block 21 includes a first half-ring 211 and a second half-ring 212, which are fixedly connected to the central connecting structure 12 respectively.

[0049] The integrated base part 1 and the separate mass block 21 facilitate the disassembly and assembly of the model when adjusting the mass block 21. Specifically, the first half-ring 211 and the second half-ring 212 have the same structural dimensions.

[0050] The inner ring of the first semi-ring 211 is provided with a first limiting surface, and the inner ring of the second semi-ring 212 is provided with a second limiting surface. Both the first limiting surface and the second limiting surface are in contact with the central connecting structure 12, which are used to limit the degrees of freedom of the mass block 21 and the central connecting structure 12 in the direction of the model axis.

[0051] The first half-ring 211 is provided with a first bolt hole 213, and the second half-ring 212 is provided with a second bolt hole 214. When the first half-ring 211 and the second half-ring 212 are fixedly connected to the central connecting structure 12, the first bolt hole 213 and the second bolt hole 214 are facing each other, and a set of fastening components are simultaneously inserted into the first bolt hole 213 and the second bolt hole 214.

[0052] The limiting surfaces on the first half-ring 211 and the second half-ring 212 cooperate with the central connecting structure 12 to prevent the mass block 21 from rotating after installation. The assembly force of the fastening components increases the pressure between the first half-ring 211 and the second half-ring 212 and the central connecting structure 12, increasing the friction between them and the central connecting structure 12, so that the mass blocks 21 on different layers are reliably connected to the central connecting structure 12.

[0053] The existing mass adjustment buoyancy blocks lack a safe fixing method, and the adjustment requires repeated disassembly and reassembly of the model shell, which is time-consuming.

[0054] The structure of the underwater vehicle model in this embodiment is modular. It is connected to the base part 1 by two semi-rings that are radially opposite each other along the model. When adjusting different working parameters, the underwater model can be quickly and accurately adjusted and safely fixed, solving the problem of inconvenience in disassembling and assembling the model shell when adjusting the mass.

[0055] The following describes the implementation process of a specific example: The dimensions, mass, density, and inertia in this example are illustrative values ​​and do not represent actual model parameters, nor do they limit the scope of protection of this solution.

[0056] Example: N = 6, L a = 1800 mm, x s = 200 mm, therefore h = 300 mm. The center coordinates of layers 1 to 6 are 0.2 m, 0.5 m, 0.8 m, 1.1 m, 1.4 m and 1.7 m respectively. Take the volume of a single module V = 0.012 m³ x 2 = 0.024 m³, and the mass of the foundation M b = 260 kg.

[0057] The target's total mass, target axial center of mass, and target pitch axis moment of inertia for three target operating conditions are shown in the table below, where all target parameters are expressed in M0. j *x cj * I yj * As shown in Table 1.

[0058] Table 1

[0059] In this example, to ensure the target total mass is consistent across the three operating conditions, we first assume the number of high-density layers is the same for each condition, denoted as q. The total mass constraint can be expressed as M = M b + V[(N - q)ρ L + qρ H ].

[0060] In the example, the total mass of the target is approximately 335 kg, and the mass of the base body is M. b = 260 kg, N = 6, V = 0.024 m³. Taking q = 2, the total mass equation becomes 0.096ρ L + 0.048ρ H = 75.

[0061] In case 2, the target axial centroid is relatively forward, so layers 2 and 3 are used as high-density layers to represent the low- and high-density arrangements. Substituting the target centroid x... c2 * ≈0.922 m, and based on the axial centroid equation, the second constraint 0.1056ρ can be obtained. L + 0.0312ρ H = 67.07.

[0062] Combining the two equations above, we can obtain two density specifications: low density ρ L ≈424 kg / m³, high density ρ H ≈714 kg / m³; the difference between the two is Δρ = ρ H - ρ L ≈290 kg / m³.

[0063] The results were verified using the pitch axis rotation inertia equation. The obtained low-density ρ... L and high density ρ H And the layout variables b corresponding to each working condition jk Substitute the values ​​into the formula for calculating the moment of inertia of the pitch axis for verification, where m jk =ρ jk V, ρ jk =ρ L +b jk (ρ H -ρ L ).

[0064] For working condition 1, B1=[0,0,1,1,0,0] is adopted, that is, the 3rd and 4th layers are high-density mass blocks (21), and the remaining layers are low-density mass blocks 21. The high-density mass blocks 21 are located in the middle, and the axial mass distribution of the model is relatively concentrated. The pitch axis rotational inertia is close to the target value of 35 kg·m² after verification; M≈335 kg, x c ≈934 mm, I y ≈35 kg·m² M≈334.976 kg, the deviation from the target value of 335 kg is about -0.024 kg; xc≈934.48 mm, the deviation from the target value of 934 mm is about +0.48 mm; Iy, after being checked by the pitch axis rotation inertia equation, is close to the target value of 35 kg·m², which meets the deviation requirements.

[0065] For condition 2, B2 = [0, 1, 1, 0, 0, 0] is used, meaning the second and third layers are high-density mass blocks 21. These high-density mass blocks 21 move forward relative to condition 1, satisfying the target axial center of mass of approximately 922 mm. The pitch axis moment of inertia, after verification, approaches the target value of 36 kg·m²; M ≈ 335 kg, x c ≈922 mm, I y ≈36 kg·m² M≈334.976 kg, the deviation from the target value of 335 kg is about -0.024 kg; xc≈922.01 mm, the deviation from the target value of 922 mm is about +0.01 mm; Iy, after being checked by the pitch axis rotation inertia equation, is close to the target value of 36 kg·m², which meets the deviation requirements.

[0066] For case 3, B3=[1,0,0,0,0,1] is used, meaning the 1st and 6th layers are high-density mass blocks 21. These high-density mass blocks 21 are distributed at both ends of the model's axial direction, increasing the distance between the mass distribution and the center of mass. After verification, the pitch axis rotational inertia approaches the target value of 42 kg·m². M≈335 kg, x c ≈934 mm, I y ≈42 kg·m² M≈334.976 kg, the deviation from the target value of 335 kg is about -0.024 kg; xc≈934.48 mm, the deviation from the target value of 934 mm is about +0.48 mm; Iy, after being checked by the pitch axis rotation inertia equation, is close to the target value of 42 kg·m², which meets the deviation requirements.

[0067] Therefore, it can be seen that the above-mentioned low-density ρ L High density ρ H and corresponding arrangement variable bjk Afterwards, the total mass, axial center of mass, and pitch axis moment of inertia of each working condition can all meet the target parameter requirements.

[0068] Example 4: The underwater vehicle model in this embodiment was designed using the design method of any of the above embodiments.

[0069] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A design method for an underwater vehicle model, characterized in that: The underwater vehicle model is cylindrical; Step 1, Model Structure Design: The model includes a base part (1) and a detachable part (2). The total mass of the base part (1) is M. b The length of the detachable part (2) along the model axis is L. a , The detachable part (2) includes multiple layers of mass blocks (21) arranged along the model axis. Each layer of mass block (21) has the same structural dimensions. After all the mass blocks (21) are assembled with the base part (1), the external structure of the base part (1) and the mass blocks (21) forms the streamlined outer surface of the model. The model has j target operating conditions, M. j * x cj * I yj * Let M represent the total target mass, the target axial center of mass, and the target pitch axis moment of inertia for the j-th working condition, respectively. j * All are equal; Step 2: Determine the number of layers N of the mass block (21); Step 3: Establish the X-axis based on the model axis: The mass of the basic part (1) is M. b The axial centroid coordinate of the basic part (1) is x b The moment of inertia of the basic part (1) about its own center of mass and pitch axis is I. yb,c The center coordinate of the mass block (21) in the first layer is x s The center coordinates of the mass block (21) in the kth layer are x k k = natural numbers from 1 to N; Step 4: Establish the model's target operating condition equations: M j * = M b + Σ k=1 N m jk M j * x cj * = M b x b + Σ k=1 N m jk x k I yj * = I yb,c + M b (x b - x cj * ) 2 + Σ k=1 N [I yk,c + m jk (x k - x cj * ) 2 ] h = L a / N x k = x s + (k - 1)h Where, m jk For the mass of the k-th mass block (21) in the j-th working condition, I yk,c Let be the moment of inertia of the k-th mass block (21) in the j-th working condition relative to its own center of mass and about the pitch axis; Step 5: Determine the mass distribution of mass block (21): The mass of the mass block (21) at different positions under each working condition is determined by trial calculation. The design values ​​of the total mass, axial centroid and pitch axis rotational inertia of each working condition are made to meet the requirements of the deviation between the target total mass, target axial centroid and target pitch axis rotational inertia. If the requirements are not met, the number of N is increased and steps three to five are repeated.

2. The design method for an underwater vehicle model as described in claim 1, characterized in that: N is an integer greater than or equal to six.

3. The design method for an underwater vehicle model as described in claim 1, characterized in that: The equivalent cross-sectional area of ​​each layer of mass block (21) perpendicular to the axis of the model is A; The volume V of each layer of mass block (21) k =A×h; The total number of mass blocks (21) forming models under different working conditions is N. All mass blocks (21) have two density specifications, denoted as low density and high density, respectively. The value of low density is ρ. L The value of high density is ρ H ; Define the layout variable for the k-th layer in the j-th working condition as: b jk ∈ {0, 1}, where 0 indicates that the k-th layer uses low density and 1 indicates that the k-th layer uses high density; The density of the k-th layer under the j-th working condition is ρ jk = ρ L + b jk (ρ H - ρ L ); Then m jk = ρ jk V k ; The steps for determining the mass of each mass block (21) under each working condition using a trial-and-error method include: S1. Establish density arrangement variables for mass blocks (21): Determine the number of high-density mass blocks (21) to be q, where q is less than N, and establish candidate arrangement variables for each working condition. Define the candidate arrangement vector for the j-th working condition as B. j =[b j,1 b j,2 , ..., b j,N Given the current N and q, generate a generator that satisfies Σb j,k =q all candidate arrangement vectors B j ; S2. Determine the layout vector obtained from the screening of standard working conditions: For the candidate layout vector B1 for each case in the standard working conditions, based on the target total mass M1 of the standard working conditions... * Establish about ρ L and ρ H The mass equation is based on the target axial centroid x under standard working conditions. c,1 * Establish about ρ L and ρ H The axial centroid equation is obtained by simultaneously solving the mass equation and the axial centroid equation to obtain the low-density ρ. L and high density ρ H Then calculate the corresponding pitch axis moment of inertia I. y,1 and I y,1 With target value I y,1 * Compare the layout vectors and select all layout vectors whose deviations meet the requirements. If no layout vectors meet the requirements, increase q and repeat steps S1-S2. If no layout vectors meet the requirements, increase N and repeat steps two to five. S3. Determine the density ρ L and high density ρ H Select one of the layout vectors obtained in step S2, and select the density ρ corresponding to the layout vector. L and high density ρ H ; S4: Two-level layout vector selection determines the layout vector B for other target working conditions. j Fix the current N, q, ρ L and ρ H For all candidate layout vectors B for other target working conditions j Calculate the corresponding axial centroid x c,j and the target axial centroid x c,j * By comparing and filtering, preliminary arrangement vectors that meet the preset deviation requirements are obtained. Then, the pitch axis moment of inertia I is calculated for all the preliminary selected arrangement vectors. y,j and the moment of inertia I relative to the target pitch axis y,j * Compare; If a final arrangement vector that meets the preset deviation requirements can be obtained through filtering, then an arrangement vector is selected from the final arrangement vectors. If the final arrangement vector that meets the preset deviation requirements cannot be obtained through screening, and the arrangement obtained from the standard working condition determined in step S2 is multiple, repeat step S3 to select a new arrangement vector and then proceed to step S4. If the current N, q, and ρ are fixed L and ρ H For all candidate layout vectors B for other target working conditions j The axial centroid x is used for calculation c,j The target requirement is not met, or the calculated pitch axis moment of inertia I y,j If the requirements are not met, increase q and repeat steps S1-S4. If there is still no feasible solution, increase N and repeat steps two to five. S5: Determine the mass block distribution for all operating conditions: The distribution of the mass block (21) in the standard working condition is determined based on the arrangement vector selected in S3; The distribution of mass blocks (21) for other working conditions is determined based on the arrangement vector selected in step S4.

4. The design method for an underwater vehicle model as described in claim 3, characterized in that: The installation positions of all mass blocks (21) are divided equally from the bow to the stern into a front adjustment zone (A), a middle adjustment zone (B), and a rear adjustment zone (C). The number of mass blocks (21) in the front adjustment zone (A), the middle adjustment zone (B), and the rear adjustment zone (C) is greater than or equal to two. The model with high-density mass blocks (21) located in the middle adjustment zone (B) is used as the model for standard working conditions.

5. The design method for an underwater vehicle model as described in claim 1, characterized in that: In the model structure design steps: First, determine the total buoyancy based on the target shape and displacement volume of the model, and then determine the target total mass M of the model based on the target net buoyancy. j * .

6. The design method for an underwater vehicle model as described in claim 1, characterized in that: In the model structure design steps: The structure of the foundation part (1) is designed according to the device to be installed inside the model, and the mass M of the foundation part (1) is determined. b The axial centroid coordinate of the basic part (1) is x b The moment of inertia of the basic part (1) about its own center of mass and pitch axis is I. yb,c .

7. The design method for an underwater vehicle model as described in claim 1, characterized in that: The basic part (1) includes a bow structure (11), a stern structure (13) and a central connecting structure (12). The central connecting structure (12) is rod-shaped, with one end connected to the bow structure (11) and the other end connected to the stern structure (13). The structure of each mass block (21) includes a first half-ring (211) and a second half-ring (212), which are fixedly connected to the central connecting structure (12).

8. The design method for an underwater vehicle model as described in claim 7, characterized in that: The inner ring of the first half-ring (211) is provided with a first limiting surface, and the inner ring of the second half-ring (212) is provided with a second limiting surface. Both the first limiting surface and the second limiting surface are in contact with the central connecting structure (12) to limit the degree of freedom of the mass block (21) and the central connecting structure (12) in the direction around the model axis.

9. The design method for an underwater vehicle model as described in claim 8, characterized in that: The first half-ring (211) is provided with a first bolt hole (213), and the second half-ring (212) is provided with a second bolt hole (214). When the first half-ring (211) and the second half-ring (212) are fixedly connected to the central connecting structure (12), the first bolt hole (213) and the second bolt hole (214) are facing each other, and a set of fastening components are simultaneously inserted into the first bolt hole (213) and the second bolt hole (214).

10. An underwater vehicle model, characterized in that: It was designed using the design method described in any one of claims 1-9.

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