CN111723532A - Numerical wave making method coupling POM and OpenFOAM - Google Patents
Numerical wave making method coupling POM and OpenFOAM Download PDFInfo
- Publication number
- CN111723532A CN111723532A CN202010459722.9A CN202010459722A CN111723532A CN 111723532 A CN111723532 A CN 111723532A CN 202010459722 A CN202010459722 A CN 202010459722A CN 111723532 A CN111723532 A CN 111723532A
- Authority
- CN
- China
- Prior art keywords
- openfoam
- pom
- data
- file
- grid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Mathematical Physics (AREA)
- Fluid Mechanics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Computing Systems (AREA)
- Pure & Applied Mathematics (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- Algebra (AREA)
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
Abstract
The invention provides a numerical wave making method for coupling POM and OpenFOAM, which is characterized in that a coarse resolution wave model of a target area is simulated by using the POM, a function relation of fluid speed changing along with height on each grid point is obtained by a polynomial fitting mode, the function relation is written into an initial file of the OpenFOAM after conversion, the OpenFOAM is driven to perform side boundary fitting calculation according to input data, during calculation, the POM continuously updates data of the target area according to time change and outputs a corresponding function relation, the FOenFOAM is recalculated once along with each updating of the POM, and pool waves similar to a real marine environment are generated within specified cycle time. According to the invention, through the coupling calculation of the POM and the OpenFOAM, the coupling of a large-scale ocean mode and a small-scale Computational Fluid Dynamics (CFD) mode OpenFOAM is realized, the scale is reduced to finer resolution data, the accuracy of a virtual test under a ship numerical water pool is improved, and the precision of the evaluation and prediction of ship hydrodynamic performance is improved.
Description
Technical Field
The invention belongs to the field of hydrodynamic force, and particularly relates to a numerical wave making method for coupling POM and OpenFOAM.
Background
The excellent hydrodynamic performance can obviously improve the economy of the ship, and the design, evaluation and optimization of the hydrodynamic performance of the ship can not leave a ship model test. A series of ship models are usually required to be designed in a traditional physical water pool experiment, so that the cost is high and the period is long; due to the existence of the scale effect, the ship model experimental data are difficult to completely accord with the flowing condition of a real ship; in addition, due to the limitation of the measurement technology, it is difficult to accurately measure the complex flow field near the ship model, and the arrangement of the test equipment also causes interference to the flow field of the ship model.
With the rapid development of Computational Fluid Dynamics (CFD), the technology of simulating the ship pool by using the CFD method has become a leading-edge technology of the existing ship hydrodynamics design, evaluation and optimization. The ship numerical water pool is lower in cost than a physical water pool, and a real-scale model can be adopted for calculation, so that the scale effect is avoided, and the complex flow condition near the ship can be captured in real time.
However, when the CFD method is used for simulation, the ship numerical pool technology mostly uses a rocker panel, a push plate wave-making method or a momentum source wave-making method, and although these wave-making methods can generate corresponding waves, these wave-making methods are mostly used for simulating ideal regular waves or waves with a fixed wave spectrum, and have a large difference from actual waves with variable fluctuation in the real marine environment, and the hydrodynamic performance of the ship actually experienced is different due to the difference of the waves, so the current wave breaking method reduces the simulation accuracy of CFD.
Disclosure of Invention
The invention aims to provide a numerical wave making method which couples a coarse resolution wave model generated by POM and a refined grid generated by OpenFOAM to obtain a wave making model which is more in line with an actual sea wave model.
Specifically, the invention provides a numerical wave making method for coupling POM and OpenFOAM, which comprises the following steps:
300, generating a dense hexahedral mesh by using a blocking function of an ICEM tool, importing the dense hexahedral mesh into OpenFOAM to generate a refined mesh by storing a mesh file converted into an OpenFOAM mode, and writing a function relation obtained from the POM into an initial file of the OpenFOAM after conversion so as to realize a POM data reading function of the OpenFOAM;
In one embodiment of the present invention, the computational mesh in step 100 is an original mesh composed of original ocean data.
In one embodiment of the invention, the equidistant distance of the grids in the computational grid is determined by the latitude and longitude.
In one embodiment of the present invention, the ocean data refers to wave data and wind field data.
In an embodiment of the present invention, in the step 200, a process of storing the mesh file converted into the OpenFOAM mode includes:
the generated hexahedron grid data is stored into a msh file used by ANSYS, and then the msh file can be converted into a grid file in an OpenFOAM mode by utilizing the fluent mesh2Foam function of OpenFOAM.
In one embodiment of the present invention, in the step 200, the process of obtaining the functional relation of the fluid velocity with height variation at each grid point by means of polynomial fitting is as follows: the velocity u, v, w and the turbulence energy k of the liquid at the grid points on the side boundaries are determined as a function of the height z, i.e. the relationship of u (z), v (z), w (z), k (z), respectively.
In an embodiment of the present invention, in the step 300, a process of writing the converted functional relation obtained in the POM into an initial file of OpenFOAM includes: placing the fitting functions U (z), v (z), w (z) in the O/U file of the initial file, and k (z) in the 0/k file of the initial file.
In an embodiment of the present invention, in the step 300, a process of writing the converted functional relation obtained in the POM into an initial file of OpenFOAM is as follows:
firstly, a shake 54foam tool is installed for OpenFOAM, then a libgroovyBC.so library file is called in a calculation control file control Dict of OpenFOAM, and then fluid data output by POM can be inserted into OpenFOAM.
In an embodiment of the present invention, in the step 400, the driving OpenFOAM to perform the side boundary fitting calculation according to the input data includes: the interboam mode and the k-turbulence model used for multiphase flow simulation.
In one embodiment of the present invention, the specified cycle time in step 400 refers to the simulation time period required to complete the experimental process.
According to the coupling calculation of the POM and the OpenFOAM, the coupling method of the large-scale ocean mode and the small-scale computational fluid dynamics CFD mode OpenFOAM is realized, the data of the POM with the horizontal resolution of several kilometers is downscaled into the resolution data of dozens of meters of the OpenFOAM, the data is further downscaled into finer resolution data, the wave simulation effect of the POM in a small-scale range is improved, the accuracy of a virtual test in a ship numerical water pool is improved, and the estimation and prediction precision of the ship hydrodynamic performance is improved.
Drawings
FIG. 1 is a schematic flow chart of a numerical wave generation method according to an embodiment of the present invention;
fig. 2 is a flow chart of a specific implementation process of the numerical wave generating method according to an embodiment of the invention.
Detailed Description
The invention is further described below by means of specific embodiments and figures.
POM (Princeton OceanModel) used in the scheme is a three-dimensional ocean mode of the original equation values of the inclined pressure, which is commonly established by Blumberg and Mellor at the university of Princeton (Princeton) in 1977.
OpenFOAM is a piece of physical field computing software developed by OpenCFD corporation under ESI group. The software is open source software which is written by C + + language and accords with GPL protocol. The software can analyze fluid, heat transfer, molecular dynamics, electromagnetic fluid and solid stress, and can realize a visual process from grid division to post-processing. The software can meet the requirements of a user on design flow matching, a physical model, required calculation precision and an automatic flow, and CAE simulation is realized through code development.
As shown in fig. 1, in an embodiment of the present invention, a numerical wave-making method for coupling POM and OpenFOAM is provided, which includes the following steps:
establishing coarse resolution waves under POM first establishes a grid of POMs, the concept of grid here is two: one is a grid of the POM mode, namely grid points separated by differential equations in a simulated area, and longitude and latitude, temperature, salinity and other data on the grid points need to be input into the POM. The second grid, which we use the original data, is the grid on which the data is distributed. If 0.5 degree by 0.5 degree accuracy is to be modeled, all that is required is to interpolate the data at the original data grid points to our calculated grid points by a particular interpolation method.
The computational mesh of the present embodiment is an original mesh composed of original ocean data. The equidistant distance of the grids in the computational grid is determined by the latitude and longitude. The ocean data refers to wave data and wind field data.
And establishing computing grids with equal intervals in the MATLAB, storing the longitudes and latitudes of the computing grids in arrays LON and LAT, writing data from the MATLAB into a specified file format which can be read by the POM, namely, the data can be read by the POM.
After the computational grid is established, firstly, data such as wave data, wind field data and the like are interpolated on the computational grid, and after the interpolation is completed, the POM can be driven to simulate a three-dimensional ocean state in a large range, namely, a coarse resolution wave model of a target area is simulated firstly.
the fluid velocity in this step is denoted by u, v, w and the turbulence energy by k.
The polynomial fitting refers to fitting functions u, v, w, k and height z, i.e. the relationship of u (z), v (z), w (z), k (z).
300, generating a dense hexahedral mesh by using a blocking function of an ICEM tool, importing the dense hexahedral mesh into OpenFOAM to generate a refined mesh by storing a mesh file converted into an OpenFOAM mode, and writing a function relation obtained from the POM into an initial file of the OpenFOAM after conversion so as to realize a POM data reading function of the OpenFOAM;
and generating the refined hexahedron grid by using an ICEM tool, generating a dense hexahedron grid by using a blocking function, storing the dense hexahedron grid as an ANSYS available msh file, converting the grid file into a grid file of an OpenFOAM mode by using a fluent mesh2Foam function of the OpenFOAM, and importing the grid file into the OpenFOAM mode.
Writing a functional relation into an initial file of OpenFOAM simulation, placing fitting functions U (z), v (z), w (z) in an O/U file, placing k (z) in a 0/k file, installing a shake 54foam tool for an OpenFOAM mode, calling a libgrovyBC.so library file in a calculation control file control of the OpenFOAM, and inserting fluid data output by POM into the OpenFOAM.
OpenFOAM carries out fitting calculation, an interFoam mode and a k-turbulence model used by multiphase flow simulation are adopted, the output condition of the POM is monitored, the side boundary fitting function of OpenFOAM is fitted and updated once when the POM outputs data once, and OpenFOAM is driven to calculate once.
And continuously circulating the steps in a simulation time period required by the completion of the experimental process, and generating waves similar to the real marine environment in OpenFOAM according to the boundary value generated by the POM every time.
According to the scheme, the coupling calculation of the POM and the OpenFOAM is realized, the coupling method of the large-scale ocean mode and the small-scale computational fluid dynamics CFD mode OpenFOAM is realized, the data of the POM with the horizontal resolution of several kilometers is downscaled into the resolution data of dozens of meters of the OpenFOAM, the data are further downscaled into finer resolution data, the wave simulation effect of the POM in a small-scale range is improved, the accuracy of a virtual test under a ship numerical value pool is improved, and the accuracy of the evaluation and prediction of the ship hydrodynamic performance is improved.
According to the scheme, the boundary speed and the turbulence energy of the POM mode are interpolated and fitted, and can be written into an OpenFOAM file with a finer grid, so that the problem of data transmission between two modes with different grid scales is solved. And POM output boundary conditions with interpolation and fitting as functions are used as initial values of OpenFOAM, and the two modes are coupled, so that the simulation efficiency and precision are improved, and the wave making of a numerical value pool is more similar to the real ocean situation.
As shown in fig. 2, the processing procedure of the present embodiment is described below by way of a specific example.
1. First, output and processing of POM data are carried out:
carrying out coarse resolution wave simulation on a target area by using a POM mode, then processing the liquid speed of a boundary by interpolation, and obtaining a function relation of flow field data on the boundary along with height change by polynomial fitting.
2. Passing the data of the POM to OpenFOAM:
firstly, OpenFOAM is used for generating a hexahedral refined grid, then a boundary speed function relation fitted by POM is written into an initial condition file of OpenFOAM, and OpenFOAM assigns values to side boundaries through the fitting speed function relation so as to refine the grid.
OpenFOAM completion simulation:
OpenFOAM can simulate and generate ship numerical pool waves according to input data, however, in a time period of a simulation experiment, POM generates a new functional relation by new data at intervals according to experiment requirements, OpenFOAM monitors output of a boundary functional relation of POM at any time, and drives OpenFOAM to calculate again along with the functional relation input by POM each time, and generates new ship numerical pool waves until the experiment is finished.
Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.
Claims (10)
1. A numerical wave making method for coupling POM and OpenFOAM is characterized by comprising the following steps:
step 100, establishing an equidistant calculation grid by using MATLAB, storing data information of the calculation grid into a corresponding array, then exporting the data information to a specified format file readable by the POM, then interpolating ocean data in a target area onto the calculation grid read by the POM, and driving the POM to simulate a coarse resolution wave model of the target area;
step 200, setting four side boundaries of the model area as rectangular boundaries, wherein the horizontal distance between the side boundaries is the horizontal resolution of the POM, outputting and calculating the fluid velocity and turbulence energy data on grid points in the grid to obtain the fluid velocity of the model boundary, and obtaining a function relation formula of the fluid velocity on each grid point along with the height change in a polynomial fitting mode;
300, generating a dense hexahedral mesh by using a blocking function of an ICEM tool, importing the dense hexahedral mesh into OpenFOAM to generate a refined mesh by storing a mesh file converted into an OpenFOAM mode, and writing a function relation obtained from the POM into an initial file of the OpenFOAM after conversion so as to realize a POM data reading function of the OpenFOAM;
step 400, driving OpenFOAM to perform side boundary fitting calculation according to input data, continuously updating data of a target area by the POM according to time change and outputting a corresponding functional relation during calculation, recalculating OpenFOAM along with each updating of the POM, and generating pool waves similar to a real marine environment within a specified cycle time.
2. The numerical wave generating method according to claim 1,
the computational mesh in step 100 is an original mesh composed of original ocean data.
3. The numerical wave generating method according to claim 1,
the equidistant distance of the grids in the calculation grid is determined by the longitude and latitude.
4. The numerical wave generating method according to claim 1,
the ocean data refers to wave data and wind field data.
5. The numerical wave generating method according to claim 1,
in step 200, the process of storing the mesh file converted into the OpenFOAM mode includes:
the generated hexahedron grid data is stored into a msh file used by ANSYS, and then the msh file can be converted into a grid file in an OpenFOAM mode by utilizing the fluent mesh2Foam function of OpenFOAM.
6. The numerical wave generating method according to claim 1,
in step 200, the process of obtaining a functional relation of the fluid velocity along with the height change at each grid point by a polynomial fitting manner is as follows: the velocity u, v, w and the turbulence energy k of the liquid at the grid points on the side boundaries are determined as a function of the height z, i.e. the relationship of u (z), v (z), w (z), k (z), respectively.
7. The numerical wave generating method according to claim 6,
in step 300, the process of writing the converted function relation obtained in the POM into the initial file of OpenFOAM is as follows: placing the fitting functions U (z), v (z), w (z) in the O/U file of the initial file, and k (z) in the 0/k file of the initial file.
8. The numerical wave generating method according to claim 1,
in step 300, the process of writing the converted function relation obtained in the POM into the initial file of OpenFOAM is as follows:
firstly, a shake 54foam tool is installed for OpenFOAM, then a libgroovyBC.so library file is called in a calculation control file control Dict of OpenFOAM, and then fluid data output by POM can be inserted into OpenFOAM.
9. The numerical wave generating method according to claim 1,
in step 400, the driving OpenFOAM to perform side boundary fitting calculation according to the input data adopts: the interboam mode and the k-turbulence model used for multiphase flow simulation.
10. The numerical wave generating method according to claim 1,
the specified cycle time in step 400 refers to the simulation time period required to complete the experimental process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010459722.9A CN111723532A (en) | 2020-05-27 | 2020-05-27 | Numerical wave making method coupling POM and OpenFOAM |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010459722.9A CN111723532A (en) | 2020-05-27 | 2020-05-27 | Numerical wave making method coupling POM and OpenFOAM |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111723532A true CN111723532A (en) | 2020-09-29 |
Family
ID=72565128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010459722.9A Pending CN111723532A (en) | 2020-05-27 | 2020-05-27 | Numerical wave making method coupling POM and OpenFOAM |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111723532A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112488718A (en) * | 2020-11-03 | 2021-03-12 | 数贸(深圳)区块链科技有限公司 | Method and system for carrying out workload certification on blocks in block chain system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106326625A (en) * | 2015-07-09 | 2017-01-11 | 中国电力科学研究院 | Method for simulating wind field by coupling WRF (weather research and forecasting) and OpenFOAM modes |
| KR20180046480A (en) * | 2016-10-28 | 2018-05-09 | 한국해양대학교 산학협력단 | Structure of drillship's moonpool for decreasing of amplitude of wave |
| CN109902427A (en) * | 2019-03-12 | 2019-06-18 | 哈尔滨工程大学 | A kind of Ship Rolling Damping viscosity flow simulation basin automatic grid division methods |
| CN110348171A (en) * | 2019-07-31 | 2019-10-18 | 山东大学 | The numerical simulation model method for building up that three-dimensional wave based on OpenFOAM is interacted with load |
-
2020
- 2020-05-27 CN CN202010459722.9A patent/CN111723532A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106326625A (en) * | 2015-07-09 | 2017-01-11 | 中国电力科学研究院 | Method for simulating wind field by coupling WRF (weather research and forecasting) and OpenFOAM modes |
| KR20180046480A (en) * | 2016-10-28 | 2018-05-09 | 한국해양대학교 산학협력단 | Structure of drillship's moonpool for decreasing of amplitude of wave |
| CN109902427A (en) * | 2019-03-12 | 2019-06-18 | 哈尔滨工程大学 | A kind of Ship Rolling Damping viscosity flow simulation basin automatic grid division methods |
| CN110348171A (en) * | 2019-07-31 | 2019-10-18 | 山东大学 | The numerical simulation model method for building up that three-dimensional wave based on OpenFOAM is interacted with load |
Non-Patent Citations (1)
| Title |
|---|
| 杨云涛;朱仁传;蒋银;缪国平;: "三维无反射数值波浪水池及波浪与结构物相互作用的模拟", 上海交通大学学报, no. 03 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112488718A (en) * | 2020-11-03 | 2021-03-12 | 数贸(深圳)区块链科技有限公司 | Method and system for carrying out workload certification on blocks in block chain system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Meneveau | Statistics of turbulence subgrid‐scale stresses: Necessary conditions and experimental tests | |
| CN108563867A (en) | A method of WRF and CFD coupled simulation wind fields are realized based on OpenFOAM | |
| CN108763683B (en) | New WENO format construction method under trigonometric function framework | |
| CN111159813B (en) | Simulation-based method and system for analyzing fluid-solid coupling of upper wave slamming lower ship | |
| Berntsen | USERS GUIDE for a modesplit σ-coordinate numerical ocean model | |
| CN111339714B (en) | Multi-scale hydrodynamic coupling method based on FVCOM and OpenFOAM models | |
| CN115496004A (en) | Internal solitary wave numerical value wave generation method based on ocean measured data | |
| CN106053016A (en) | Method for pushing plate to create random wave | |
| Burić et al. | A numerical investigation of tidal current energy resource potential in a sea strait | |
| Jones et al. | Modelling of complex coastal environments: Some considerations for best practise | |
| CN111723532A (en) | Numerical wave making method coupling POM and OpenFOAM | |
| CN110378518B (en) | Underwater power flow prediction method adopting LSTM-NARX hybrid model | |
| Salehipour et al. | A higher order discontinuous Galerkin, global shallow water model: Global ocean tides and aquaplanet benchmarks | |
| CN113158556A (en) | Short-time high-precision forecasting method for regional water level | |
| Giorgi | Nonlinear hydrodynamic modelling of wave energy converters under controlled conditions | |
| CN116362108A (en) | Oblique knocking flow field reconstruction method and system based on test data | |
| Vyzikas et al. | Numerical Modelling | |
| CN114611423A (en) | Three-dimensional multiphase compressible fluid-solid coupling rapid calculation method | |
| Zullah et al. | Review of fluid structure interaction methods application to floating wave energy converter | |
| Faraggiana et al. | Multi-directional waves and time domain perturbed field visualization of the WaveSub device | |
| CN103425835B (en) | A kind of numerical method for studying water-aerosphere face evolutionary process | |
| Caires et al. | North Sea wave analysis using data assimilation and mesoscale model forcing winds | |
| de Sousa Veras et al. | Modeling Tidal Streams of the Boqueirão Channel Using Delft3D | |
| Lu et al. | A topology-alterative two-phase flow solver and its validation for a dynamic hydraulic discharge process | |
| CN116011356B (en) | Submarine pipeline scouring prediction method based on ConvLSTM and OpenFOAM numerical computation coupling |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |