Underwater cable laying robot jet sword optimization method based on computational fluid mechanics

Abstract

The invention discloses an underwater cable laying operation robot jet sword optimization method. The method comprises the following steps: step 1, establishing a geometric model and a grid model of an underwater cable laying operation robot jet sword based on a computational fluid mechanics method; 2, performing jet flow simulation on a jet sword of the underwater cable laying operation robot to obtain simulation data; step 3, obtaining structure parameters of a jet sword through a jet sword model established by an actual underwater cable laying operation robot, and designing an orthogonal table according to the structure parameters; 4, according to the structure parameter combination of the orthogonal table, the steps 1-2 are repeated, modeling and jet flow simulation are conducted on the jet sword, the pressure value and the jet flow speed value corresponding to each set of jet sword structure parameters are obtained, and the optimal combination of the jet sword structure parameter orthogonal experiment is obtained with the pressure value and the jet flow speed value as optimization indexes. According to the method, the underwater cable laying operation robot jet sword model can be accurately and rapidly established, and the number of experiments can be reduced to the maximum extent.

Description

Technical Field

[0001] The invention belongs to the field of underwater cable laying technology and computational fluid dynamics, and in particular relates to an optimization method for a jet sword of an underwater cable laying robot based on computational fluid dynamics. Background Art

[0002] The underwater cable-laying robot is a special robot used to lay submarine optical cables, electric cables and other communication and energy transmission lines in an underwater environment. As an emerging technical solution, the underwater cable-laying robot has significant advantages over the traditional submarine cable laying method. The jet sword is the main structure of the underwater cable-laying robot. Its main function is to impact the seabed soil with the high-pressure jet generated by the jet sword nozzle to produce the groove required for burying the submarine cable. Over the years, many companies at home and abroad have developed underwater cable-laying robots, such as the Korea Robotics Research Institute in 2020, but most of these institutions pay attention to the overall design and actual cable-laying efficiency of the underwater cable-laying robot, and rarely pay attention to the optimization research of the robot jet sword. However, the optimization of the jet sword is an extremely important part of improving the working efficiency of the underwater cable-laying robot. Summary of the invention

[0003] The purpose of the present invention is to improve the working efficiency of the underwater cable laying robot by optimizing the jet sword of the underwater cable laying robot. The present invention proposes an optimization method for the jet sword of the underwater cable laying robot based on computational fluid dynamics, which comprehensively considers the influence of structural parameters such as the number, angle, and nozzle diameter of the jet sword nozzles on the working efficiency of the jet sword, and establishes a structural model and a grid model of the jet sword in the computational fluid dynamics software. Combined with the orthogonal experimental design method, the number of experiments can be reduced to the greatest extent, and the optimal jet sword design scheme can be obtained.

[0004] The invention provides a method for optimizing the jet sword of an underwater cable laying robot, comprising the following steps:

[0005] Step 1: Establish the geometric model and mesh model of the underwater cable laying robot jet sword based on computational fluid dynamics method

[0006] Step 2, simulating the jet of the jet sword of the underwater cable laying robot to obtain simulation data;

[0007] Step 3, obtaining the structural parameters of the jet sword through the jet sword model established by the actual underwater cable laying operation robot, and designing an orthogonal table according to the structural parameters;

[0008] Step 4, according to the structural parameter combination of the orthogonal table, repeat steps 1-2, model the jet sword and perform jet simulation, obtain the pressure value and jet velocity value corresponding to each set of jet sword structural parameters, and use the pressure value and jet velocity value as optimization indicators to obtain the optimal combination of the jet sword structural parameters in the orthogonal experiment.

[0009] Furthermore, in step 1, the geometric model and mesh model of the jet sword of the underwater cable laying robot are established based on the computational fluid dynamics method. The specific steps are as follows:

[0010] Step 1.1, use ANSYS ICEM software to create the jet sword geometry model and flow field area;

[0011] Step 1.2, using ANSYS ICEM software to mesh the geometric model and flow field area of ​​the underwater cable laying robot jet sword, specifically using an unstructured meshing method to create a mesh model of the underwater cable laying robot jet sword.

[0012] Furthermore, in step 2, the jet simulation of the jet sword of the underwater cable laying robot is performed to obtain simulation data, which specifically includes:

[0013] Import the mesh model .msh file of the jet sword into ANSYS Fluent software, and use the SIMPLE solution method to set the fluid simulation conditions, including boundary conditions and solution conditions;

[0014] The boundary conditions include the jet inlet, jet outlet and wall position;

[0015] The solution conditions refer to the methods used when the ANSYS Fluent software runs the solution, including SIMPLC, SIMPLCE, and PISO; a steady-state calculation method is adopted, a fixed number of iterations is set, the jet simulation of the jet sword of the underwater cable laying robot is realized, simulation data is obtained, and the pressure value and jet velocity value of the jet sword outlet are monitored by setting report definitions.

[0016] Furthermore, step 2 also includes processing the simulation data of the underwater cable laying robot jetting sword jet through the fluid mechanics post-processing software ANSYS CFD-POST to obtain the pressure field, velocity field cloud map and vector map generated by the underwater cable laying robot jet process.

[0017] Furthermore, in step 4, the structural parameters of the jet sword include the number of nozzles, the inclination angle, the nozzle diameter and the nozzle shape.

[0018] Beneficial effect: In the optimization work of the jet sword of the underwater cable laying robot described in the present invention, how to design the optimal combination of jet sword structural parameters to improve the jet sword's cable laying efficiency is the most tedious part of the research work. The underwater cable laying robot jet sword optimization method based on computational fluid dynamics numerical analysis and orthogonal design proposed in the present invention can accurately and quickly establish the underwater cable laying robot jet sword model and minimize the number of experiments.

[0019] The present invention successfully establishes the jet simulation motion of the underwater cable laying robot by adopting computational fluid dynamics and orthogonal experimental design. At the same time, through orthogonal experimental analysis, it successfully solves the problem of too many test times and too large parameter combinations, providing theoretical support for improving the cable laying efficiency of the underwater cable laying robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of an optimization method of a jet sword of an underwater cable laying robot based on numerical analysis of computational fluid dynamics according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of a geometric model and a flow field region according to an embodiment of the present invention;

[0022] Figure 3 is a schematic diagram of a grid model according to an embodiment of the present invention;

[0023] Figure 4 is a schematic diagram of steady-state calculation simulation according to an embodiment of the present invention;

[0024] Figure 5 is an orthogonal design representation according to an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of pressure field and velocity field according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention provides an optimization method for the jet sword of an underwater cable laying robot based on computational fluid dynamics. Figure 1 As shown, the following steps are included:

[0027] Step 1: Establish the geometric model and mesh model of the jet sword of the underwater cable laying robot based on the computational fluid dynamics method. The specific steps are as follows;

[0028] Step 1.1, use ANSYS ICEM software to create a simple geometric model of the jet sword and the flow field area; the flow field area is Figure 2 Shown in the middle grey area;

[0029] Step 1.2, using ANSYS ICEM software to mesh the geometric model and flow field area of ​​the underwater cable laying robot jet sword, and using an unstructured meshing method to create a mesh model of the underwater cable laying robot jet sword, such as Figure 3 As shown;

[0030] Step 2, in the two calculation methods of steady state and transient state in the actual simulation of Fluent, the steady state calculation method is selected to realize the jet simulation of the jet sword of the underwater cable laying robot;

[0031] Import the mesh model .msh file of the jet sword into ANSYS Fluent software, and use SIMPLE solution method to set boundary conditions, solution conditions and other fluid simulation conditions; the boundary conditions include boundary conditions such as jet inlet, jet outlet and wall position;

[0032] The solution conditions refer to the methods used when ANSYS Fluent software runs the solution, including SIMPLC, SIMPLCE, PISO and other methods. You can directly select them in ANSYS Fluent before the simulation; use the steady-state calculation method, set a fixed number of iterations, and realize the jet simulation of the underwater cable laying robot jet sword to obtain simulation data, such as Figure 4 As shown, the pressure and velocity values ​​at the jet sword outlet are monitored by setting the report definition.

[0033] Step 3, using the fluid mechanics post-processing software ANSYS CFD-POST to process the data of the underwater cable laying robot jet simulation, the pressure field, velocity field cloud map and vector map generated by the underwater cable laying robot jet process are obtained, so that the simulation results under different conditions can be observed more intuitively;

[0034] Step 4, by comparing the jet sword model established by the actual underwater cable laying operation robot, the structural parameters of the jet sword are obtained, including the number of nozzles, the inclination angle, the nozzle diameter and the nozzle shape;

[0035] And evenly select level values ​​within the optimization range of the jet sword structure parameters to perform orthogonal array design, such as Figure 5 As shown, a typical parameter group is obtained;

[0036] According to the main output parameters of fluid simulation and references, it can be known that the pressure value and the jet velocity value are the optimization indicators for this time; the optimization range refers to the reasonable modifiable and adjustable range of the jet sword structural parameters.

[0037] Step 5, according to the parameter combination of the orthogonal design table, return to step 1, model the jet sword and perform jet simulation again, obtain the orthogonal experimental results, and re-obtain the optimal combination of the orthogonal experiment.

[0038] In order to obtain the optimal pressure and speed values, the jet sword of the underwater cable laying robot was modeled and jet simulation was performed many times to obtain the experimental results. By comparing the pressure value and the jet speed value, the optimal value of the two was taken to obtain the optimal combination of the orthogonal experiment.

[0039] The present invention provides a method for an underwater cable laying robot jet sword based on numerical analysis of computational fluid dynamics. The method includes: establishing a geometric model and a mesh model of the underwater cable laying robot jet sword based on ANSYS ICEM software; using ANSYS Fluent software to implement the jet motion simulation of the underwater cable laying robot jet sword and obtain the pressure value and velocity value of the jet sword outlet through report definition; using ANSYS CFD-POST software to process the simulation data to obtain the pressure field and velocity field cloud map of the jet sword jet motion; orthogonally designing the jet sword structural parameters to obtain a typical parameter group and determine the optimization index; and modeling and jet simulation of the jet sword again according to the typical parameter group to obtain the optimal combination of the orthogonal experiment. By adopting the above technical solution, the present invention solves the optimization problem of the underwater cable laying robot jet sword, and greatly reduces the heavy workload caused by excessive parameter combinations, providing a theoretical basis for improving the working efficiency of the underwater cable laying robot.

Claims

1. A method for optimizing the jet sword of an underwater cable laying robot, characterized in that: The steps include: Step 1: Establish the geometric model and mesh model of the underwater cable laying robot jet sword Step 2, simulating the jet of the jet sword of the underwater cable laying robot to obtain simulation data, wherein the simulation data includes a pressure value and a jet velocity value at an outlet of the jet sword; Step 3, obtaining the structural parameters of the jet sword through the jet sword model established by the actual underwater cable laying operation robot, and designing an orthogonal table according to the structural parameters; Step 4, according to the structural parameter combination of the orthogonal table, repeat steps 1-2, model the jet sword and perform jet simulation, obtain the pressure value and jet velocity value corresponding to each set of jet sword structural parameters, and use the pressure value and jet velocity value as optimization indicators to obtain the optimal combination of the jet sword structural parameters in the orthogonal experiment.

2. According to the method for optimizing the jet sword of an underwater cable laying robot according to claim 1, it is characterized in that: In step 1, the geometric model and mesh model of the jet sword of the underwater cable laying robot are established. The specific steps are as follows: Step 1.1, use ANSYS ICEM software to create the jet sword geometry model and flow field area; Step 1.2, using ANSYS ICEM software to mesh the geometric model and flow field area of ​​the underwater cable laying robot jet sword.

3. According to claim 2, a method for optimizing the jet sword of an underwater cable laying robot is characterized in that: In step 1.2, an unstructured grid division method is used to create a grid model of the jet sword of the underwater cable laying robot.

4. According to claim 2, a method for optimizing the jet sword of an underwater cable laying robot is characterized in that: In step 2, the jet simulation of the jet sword of the underwater cable laying robot is performed to obtain simulation data, which specifically includes: Import the mesh model .msh file of the jet sword into ANSYS Fluent software, and use the SIMPLE solution method to set the fluid simulation conditions, including boundary conditions and solution conditions; The boundary conditions include the jet inlet, jet outlet and wall position; The solution conditions refer to the methods used when the ANSYS Fluent software runs the solution, including SIMPLC, SIMPLCE, and PISO; a steady-state calculation method is adopted, a fixed number of iterations is set, the jet simulation of the jet sword of the underwater cable laying robot is realized, simulation data is obtained, and the pressure value and jet velocity value of the jet sword outlet are monitored by setting report definitions.

5. According to claim 1, a method for optimizing the jet sword of an underwater cable laying robot is characterized in that: Step 2 also includes processing the simulation data of the underwater cable laying robot spraying sword jets to obtain the pressure field, velocity field cloud map and vector map generated by the underwater cable laying robot's jet process.

6. According to claim 5, a method for optimizing the jet sword of an underwater cable laying robot is characterized in that: Specifically, the simulation data of the underwater cable laying robot jet sword jet is processed by the fluid mechanics post-processing software ANSYS CFD-POST.

7. According to claim 1, a method for optimizing the jet sword of an underwater cable laying robot is characterized in that: Step 4, the jet sword structural parameters include the number of nozzles, inclination angle, nozzle diameter and nozzle shape.

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