bemrosetta/bemrosetta

Hydrodynamic coefficients viewer and converter for Boundary Element Method solver formats

BEMRosetta

Hydrodynamic coefficients viewer and converter for Boundary Element Method solver formats.

Boundary Element Methods are extensively used to model hydrodynamic forces in offshore devices like ships, offshore wind platforms and wave energy converters. These solvers use device geometry mesh to get some hydrodynamics coefficients as radiation damping, added mass, wave diffraction force, and wave excitation force. All these data is saved in file formats incompatible between them. These may avoid to use the coefficients between programs.

BEMRosetta allows to load the hydrodynamic coefficients from a format saving it in another. In addition it allows to compare the results obtained between programs, the results between similar geometries and the same geometry with different discretization levels.

Moreover, BEMRosetta allows to view and visually compare the meshes from different programs.

BEMRosetta runs on Windows and Linux, no install is necessary in Windows (see Install), and it includes a GUI, a command line version, a library (DLL), and glue code for Python.

Features

- Supported file formats

• BEM coefficients

  • Load-View

    • Wamit: .out, .3sc, 3fk, .1, .3, .4, .hst, .7, .8, .9, .12s, .12d
    • Ansys AQWA: .lis, .ah1, .qtf
    • OrcaWave: .yml, .owr (requires OrcaWave installed)
    • HAMS: ControlFile.in
    • Nemoh and Capytaine: Nemoh.cal, Mesh/Hydrostatics*.dat, Mesh/KH*.dat, RadiationCoefficients.tec, ExcitationForce.tec, DiffractionForce.tec, FKForce.tec, IRF.tec
    • Capytaine: .nc
    • Bemio: .h5
    • Diodore: .hdb
    • Hydrostar: .out
    • OpenFAST-Wamit: HydroDyn.dat
    • SeaFEM/TDyn-Nemoh: .flavia.inf, RadiationCoefficients.tec, ExcitationForce.tec, DiffractionForce.tec, FKForce.tec
    • FOAMM: .mat

  • Save

    • Wamit: .out, .1, .3, .hst, .4, .7, .8, .9, .12s, .12d
    • HAMS: ControlFile.in and all the folder structure.
    • Bemio: .h5
    • Diodore: .hdb
    • Ansys AQWA: .qtf
    • OpenFAST-Wamit: HydroDyn.dat

• Case files

  • Load-View
    • HAMS: ControlFile.in
    • Ansys AQWA: .dat
    • Nemoh and Capytaine: Nemoh.cal and all the folder structure.
  • Save
    • HAMS: ControlFile.in and all the folder structure.
    • Nemoh and Capytaine: Nemoh.cal and all the folder structure.

• Mesh files

  • Load-View
    • Wamit: .gdf, pan.dat
    • HAMS: .pnl
    • Nemoh and Capytaine: .dat
    • Ansys AQWA: .dat
    • Hydrostar: .hst
    • Salome: .dat
    • STL format: .stl (binary and text)
    • SeaFEM/TDyn: .msh
    • GMSH: .msh
    • OrcaWave: .owr (requires OrcaWave installed)
  • Save
    • Wamit: .gdf
    • HAMS: HullMesh.pnl, WaterplaneMesh.pnl
    • Ansys AQWA: .dat
    • STL format: .stl (binary and text)

• Time domain simulations

  • Load-View
    • OpenFAST: .out, .outb
    • Deeplines Wind: .db
    • Ansys AQWA Naut: .lis
    • CSV: .csv
  • Save
    • OpenFAST: .out
    • CSV: .csv

• Turbulent wind

  • Load

    • OpenFAST: .bts, .sim
    • DNV Bladed: .wnd

  • Save

    • OpenFAST: .bts

- Load the hydrodynamic coefficients from one format and save them in another

The goal is to have a good robustness in the handling of files

- Compare the hydrodynamic coefficients for the same geometry from different software

• Damping for the same geometry got from different solvers

• Excitation force for the same geometry got from different solvers_

- Forces handling

It simmetrizes the available forces in all directions, averaging them when they are available on both possitive and negative headings. Some examples cases:

• Only the forces on positive headings from 0 to 180º have been processed: Symmetrize duplicates them to the negative heading values from 0 to -180º
• Both positive and negative headings forces have been processed: Symmetrize averages them

- Compare the hydrodynamic coefficients for the same geometry for different discretization levels

- Compare the hydrodynamic coefficients for different geometries

• Damping for different offshore wind floating platforms_

• Excitation force for different offshore wind floating platforms_

- FOAMM connection

Finite Order Approximation by Moment-Matching (FOAMM) is an application developed by N. Faedo, Y. Peña-Sanchez and J. V. Ringwood in the Maynooth University's Centre for Ocean Energy Research (COER), that implements the moment-matching based frequency-domain identification algorithm.

BEMRosetta allows an interactive and seamless FOAMM connection to get state space coefficients.

- Mesh loading, combining them for visual comparison

Several meshes can be loaded in this basic viewer, allowing a visual comparison of geometries.

- Mesh handling

• Interactive mesh rotation and translation around user defined center
• Automatic free surface, underwater surface, center of buoyancy, hydrostatic stiffness matrix, and other parameters calculation
• Improved viewer including dropdown menu in viewer screen
• Hydrostatic stiffness matrix viewer
• Mesh healing option

- Case launcher, Nemoh & HAMS

Added Nemoh and HAMS launcher. It can loadexisting files from HAMS, Nemoh or ANSYS AQWA, it lets you editing it, and creates the set of files to launch Nemoh and HAMS from a .bat file (it replaces the classic Nemoh MATLAB launcher)

- Time domain simulations

BEMRosetta includes a time domain simulations viewer supporting OpenFAST, Deeplines Wind, Ansys AQWA Naut and csv formats, designed to be very easy to use. Files may be opened by drag and drop, and parameters are filtered by name or units.

- OrcaFlex command line

If you have an OrcaFlex licence, the command line version allows you to perform operations not available directly in OrcaWave/OrcaFlex, like:

• Calculating hydrodynamic coefficients with OrcaWave.
• Performing time domain simulations with OrcaWave.
• Save the results of time domain simulations to .csv files.

- Other

All files, mesh, case or BEM files, can be loaded by Drag and Drop or Copy and Paste from file explorer in Windows and Linux.

Acknowledgments

S. Husain, J. C. C. Portillo, J. C. C. Henriques, M. J. Sanchez-Lara, J. Galvan, A. Otter, M. Alonso, A. Aristondo.
Some file parsing strategies taken from the BEMIO project.
Done with the U++ multiplatform library.

License

Copyright © 2019-2021 Iñaki Zabala, Markel Peñalba, Yerai Peña-Sanchez, Thomas Kelly.

BEMRosetta is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
BEMRosetta is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details. You should have received a copy of the GNU General Public License along with BEMRosetta. If not, see http://www.gnu.org/licenses/.

bemrosetta's Issues

Archimedes Function Error

My current process of using the Archimedes is as follows:

• Import .stl file
• Set mass on the 'Process' tab, then click on 'Mass' to set the numerical value
• Click the Archimede button on the 'Move' Tab

For example the geometry (attached) I'm working on right now, a hexagon with circumradius of 5m and height of 7.5m

If I set the mass to be 137909kg, the submerged volume should be 134.54 m^3 (rho=1025 kg/m^3)
137909g = -1025g*V

But BEMRosetta calculates submerged volume as 211.1 m^3?

Am I missing something or is the function not working properly?
Hexagon_10m_centered.zip

Best,
Yi

Morison elements

Dear @izabala123
I tried to read mesh from AQWA with BEMRosetta,but i found that the BEMRosetta can not read the morison elements which i have already set in AQWA ,i do not know how to read morison elements with BEMRosetta.

Best regard!
zz

Using BEMRosetta to load GMSH file error "Field #2 not found in line: '$EndMeshFormat'

My GMSH file is like this, I dnon't how to handle this error.

Long clonging time

It seems that you are storing executable files in the repository bin directory. It contributes to significant size of the repository. For example when you cloning BEMRosetta repository it weights 1.3 GB.

As an alternative you can consider using "Releases" (https://github.com/BEMRosetta/BEMRosetta/releases) or "Packages" (https://github.com/orgs/BEMRosetta/packages?repo_name=BEMRosetta).

Feature request: load Salome mesh dat file in BEMRosetta

Dear developer,

Would it be possible to add up new features that can load Salome mesh dat file in BEMRosetta.
Salome is an open-source software which can create geometry and mesh. Therefore, I think it can be a good preprocessor for BEM simulation.

Below is a zipped folder including three files. The file with name OC3Spar.dat is the mesh file from Salome. It is half of a spar foundation. The file with name Dat2Pnl.f90 is a fortran code programmed by myself. I programmed this code to convert Salome data file to HAMS pnl file. And the file with name OC3Spar.pnl is the converted results, which can be visualized in BEMRosetta.
OC3Spar.zip

Please allow me to introduce this "dat" format based on my understanding.

line 1 includes two integers: 951 and 1084. The first integer is the total number of nodes. The second integer is the total number of elements, including edge elements, surface elements and brick elements. So in my example, it has 951 nodes and 1084 elements. And my example has no brick elements. But there exists edge elements and surface elements.

Line 2 ~ 952 : the totally 951 rows described 951 node information. Each row includes one integer and three real numbers. The integer is the index of this node, followed by x-coordinate, y-coordinate and z-coordinate. For example, line 2 includes: 1 4.70000000000000e+00 0.00000000000000e+00 -1.20000000000000e+02. That denotes the node index is 1. node x-coordinate is 4.70000000000000e+00, node y-coordinate is 0.00000000000000e+00, and node z-coordinate is -1.20000000000000e+02.

Line 953 ~ 2036: the totally 1084 rows described 1084 element information. Each row includes 4 or 5 integers. The first integer is the element index. The second integer denotes the type of this element. It is hundreds. The hundreds place denotes the dimension of this element( i.e. number 1 denotes edge elements, number 2 denotes surface element and number 3 denotes brick elements). And the ones place denotes the number of node connectivity(i.e number 3 denotes that this element has 3 nodes, so it is triangle element. Number 4 denotes that this element has 4 nodes, so it is quadrilateral element).
For example, line 953 is: 1 102 5 3. That means the element index is 1, it is a edge element and it has two nodes. The index of these two nodes are 5 and 3 respectively.
Line 1149 is: 197 204 1 41 42 16. That means the element index is 197, it is a surface element and it has four nodes. The index of these four nodes are 1, 41, 42, 16 respectively. The sequence of node index will determine the face normal direction.
Line 1156 is: 204 203 35 34 48. That means the element index is 204, it is a surface element and it has three nodes. The index of these three nodes are 35,34,48 respectively. The sequence of node index will determine the face normal direction.

Above is an introduction to Salome dat file format. For BEM, I think we only need surface element with type 203 and 204.

As I have mentioned, above zipped folder has a fortran code to convert Salome dat file to HAMS pnl file. The key idea of this code is to extract all nodes and all surface elements with type 203 and 204, but exclude edge elements.

Dear developer, if you have interest to implement new features that can load Salome mesh dat file in BEMRosetta, Although this code is not elegant, I hope it can reduce sort of your work.

Regards,

Error "No rule to make target" when compiling and generating BEMRosetta.out

Hi.

I've pulled BEMRosetta to my PC, and there is an error when I compile and generate the BEMRosetta.out.

Like below screenshot:

Can you help me check this error out?
Many Thanks.
My Vang.

About hydro coeff in BEMRosetta

Hi,
I am using Nemoh and BEM Rosetta for my work. I need to check the excitation force in BEMRosetta. But when i creat two bodied or more in nemoh and after running in Neomh i want to see the results in BEMRosetta, i cant see the results about the second body. It turns about zero all the time.
Kindly help.

BEMRosetta crashes after loading .gdf file in mesh handling tab

Hi!

Thanks a lot for the development of this tool, it has helped me out a lot during my thesis!

At the moment I am running BEMRosetta via the .exe file (downloaded on 01-06-2022) on windows 10. I am trying to calculate hydrodynamic parameters via BEMRosetta and Nemoh, and this works out flawlessy. Right now I would like to do some validation on my tests, and for this I have gotten a .gdf mesh file that I would like to test with Nemoh and compare to Wamit outputs. For this I need to convert the .gdf file to a Nemoh .dat file. However, when I try to load the .gdf file in the mesh handling tab the BEMRosetta program crashes and I am not sure why. Could it be that the file I am trying to load is too large? Unfortunately I have no way of making another much smaller .gdf file so I cannot test it. I have added a screenshot of the program, it crashes after I click the load button. I have also attached the .gdf file to reproduce the issue, but as github doesn't allow for .gdf file attachments I have converted it into plain text, please let me know if that works :)

reducedbrov2heavy.txt

Problem in The Hydrodynamic Coefficient

Dear @izabala123

I am an undergraduate student and currently working on my final project. I am trying to model an OWC cylinder using Nemoh, but I can't see the results of K, Kirf, RAO, QTF and others on BEMRosetta.

like this,

Only a few results that I can see. I need RAO data but it doesn't appear in BEMRosetta. do you know where the problem is? i hope you can help me. Thank you..

Best Regards,
Dith

Loading Nemoh results and conversion

Hi there,

Many thanks for sharing your application first of all, it looks neat!

Now going over to my issue:
I am interested in conversion of my Nemoh results into .Wamit such that I can upload this data into different softwares related to wind turbine design (like Bladed, OpenFAST etc.). Your tool should be capable of doing this, correct?

However, when I try to go over to the hydrodynamic coefficients section and load my .tec files it gives as warning "Unknown BEM file extension". Also attached the warning.

Am I missing something?

Many thanks in advance!

Bladed support

Dear Iñaki,

Yes, you helped me a lot! These are the files the program Bladed is asking for. The .cfg file is only needed for the IALTFRC value so that would be easy. Also, the .frc is easy to make by putting the mass/inertia matrix in correct format. The .out file is a bit more tricky.

Kind regards,

Martijn

Originally posted by @martijnwilpshaar in #3 (comment)

How to output the hydrostatic result .hst (WAMIT) from the multi-body results of Nemoh?

Hello, izabala123!

Is it possible to output the .hst file from the multi-body results of Nemoh? It seems like Nemoh cannot calculate the static problem of multi-body, because one can only specify one mesh.cal in the case directory. But I noticed that in the BEMRosetta-BEMSolver, it is possible to save multiple mesh.cal files, such as mesh_0.cal, mesh_1.cal, mesh_2.cal...

So, I was wondering is there a way to output a static file .hst for the multi-body of Nemoh, even if the coupling between the free degrees of different bodies are not considered?

BTW, even though BEMRosetta can give multiple mesh.cal files, but it looks like the Nemoh's hydrosCal.exe cannot use them. Do you have any ideas?

Thanks so much

Chao Li

Combine Multiple Bodies and Export as NEMOH.dat File

Issue Description:
After combining four bodies written in NEMOH.dat format (attached) and exporting the resulting body as a NEMOH.dat file, I encountered a segmentation fault error when attempting to run NEMOH. The specific error message received is:

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Additional Context:
Exporting the combined bodies as STL, then loading and re-exporting them as NEMOH.dat files works without errors, albeit with changes to the mesh.

How can I export the combines mesh files without the need to do the export as STL step.

NEMOH_Meshes.zip

Can BemRosetta show the curve on the line paralleled to diagonal of QTF matrix?

Hello @izabala123,

BemRosetta can show the curves on the diagonal line, horizontal line and vertical line of a QTF matrix. But often we concern more about the values on the line paralleled to diagonal or back-diagonal, because they represent same difference-frequency or sum-frequency. So, is there a way to displace curve on the line paralleled to diagonal in BemRosetta?

Thank you!

Chao Li

Phase angle of wave excitation loads for offset body, and added mass and radiation damping matrix for multibodies in AQWA

Dear izabala123

I found some issues about the phase angle of wave excitation loads for offset body, and added mass and radiation damping matrix for multibodies. The issues were originally posed in A designed two-body hinged raft wave energy converter: From experimental study to annual power prediction for the EMEC site using WEC-Sim by Siya.

Let me briefly describe the problem. For an offset body with its COG away from the origin of global coordinate system in the XY plane (this configuration is usually found in multibody cases), the phase angle output by AQWA is defined as the local parameter phase angle. But the phase angle output by WAMIT is defined as the global phase angle, which is equal to the local parameter phase angle + global wave phase angle (global wave phase angle is defined as the phase angle of the local coordinate origin with relative to the global coordinate origin, and is related to the spatial location of the body)

AQWA

WAMIT

For a body with its COG located at the origin of global coordinate system in the XY plane

PhaseAngleWAMIT = -PhaseAngleAQWA

But the definition is not perfect, because it is given based on the premise that the wave phase angle is zero (COGx = COGy = 0). For an offset body, the correct phase angle should be

PhaseAngleWAMIT = -PhaseAngleAQWA - k * [x * cos(beta) + y * sin(beta)]
where PhaseAngleAQWA is the phase angle ouput by AQWA, k is the wave number, x and y are locations of the body, and beta is the wave heading.

The real parts of wave excitation loads in 0 degrees wave heading obtained based on -PhaseAngleAQWA are (0.5 and 0.75 are the damping coefficients of external lid, which have no effects on the results)

The corrected results in 0 degrees wave heading are

The corrected results in 10 degrees wave heading are

% ======================================
Another issue arises in the added mass and radiation damping matrices

I convert the AQWA results into WAMIT format using BEMRosetta, the dimensioned added mass (1,2,wave frequency = 0.0329999 rad/s) * 1025 is -1.7339E+06, and added mass (2,1,wave frequency = 0.0329999 rad/s) * 1025 is -1.8397E+06.

However, for the converted WAMIT results, the added mass (1,7,wave period = 1.903996E+02 s) is -1.794829E+03 (the dimensioned added mass is -1.8397e+06), and the added mass (7,1,wave period = 1.903996E+02 s) is -1.691610E+03 (the dimensioned added mass is -1.7339e+06)

It appears that additional converisons need to be applied to the added mass and radiation damping matrices for multibody cases.

WEC-Sim BEMIO seems to have the same issues regarding the wave phase angle and radiation coefficients.

Some related results can be found here

I hope these efforts meet with your approval

Best regards,
Tianyuan

Can not Add an stl file

Hello,
I am trying to open an stl file in BEMRosetta but it shows this error.

Problem loading 'C:\Desktop\SDPSW\BasicFlapModified.STL'
[File: 'C:\Desktop\SDPSW\BasicFlapModified.STL', line: 2]: . 'facet normal' field not found.

what can be the problem?.
thank you.

Installation on Linux

Hello,
I am trying to install BEMRosetta on Linux and I finish the first step (Upp installation and download BEMRosetta through it).
However after compiling the main.cpp, I can't figure out how to run the program. Could you please elaborate?

Thank you in advance!
Best,
Thanasis Dermatis

Load the Multi-body hydrodynamic coefficient(.out file) from hydrostar

Hi @izabala123

When loading the Multi-body hydrodynamic coefficient(.out file) from Hydrostar, it reported a bug as follows.

It seems that the BEMRosetta can only load the single-body coefficient(.out file) from Hydrostar? The file exported from Hydrostar is attached.

Best regards,
oc4.zip

How to convert WAMIT format to DeepLines HDB format ?

Hello !

I've just discovered BEMRosetta and it is really useful to quickly display HDB and convert from a format to another.

Unfortunately, I am used to compute HDB using WAMIT (.1, .3, .4 ...) and I would be interesting into converting it in the DeepLines type (.hdb) to be able to run a floating offshore wind mooring study.

I know it is not a conversion available into BEMRosetta but I was wondering if you can provide the code for the conversion DLW to WAMIT ? It could help me create the reverse one.

Thanks a lot
Alex

Installation of BEMRosetta

Hi,

Thank you for releasing the code. However, when I followed the steps shown on the website carefully and installed BEMRosetta, after installing the U++ compiler, I always failed to use command "umk" to comply the BEMRosetta to Arch Linux systems, or Window 7 systems. They all suggested similar errors, many ".h" files cannot be found such as Core/Core.h, zlib.h, Draw.h..... I am not sure whether you met these problems before.

Hope you can help me with this issue. Many Thanks,

Best Regards,

Lei

Can't export mesh after processing. Orcawave support

Hello,

I imported a geometry from Gmsh and changed the COG using the 'process' tab in 'Mesh Handling'. Then I exported the mesh into the Nemoh.dat format. The change in COG is not reflected on the new file created. How can I solve this ?

Please help.

Thanks.

Infinite frequency addedd mass

Dear izabala123
I found AQWA calculates the infinite frequency added mass as ADDEDMASS_HF (100.0RAD/S), which is different from that of BEMRosetta. Does BEMRosetta calculate the infinite frequency added mass based on radiation IRF as $R_{ij}(t)=\frac{2}{\pi}\int_{0}^{\infty}B(\omega)\cos(\omega t)d\omega$ and $A_{ij}(\infty)=A_{ij}(\omega)+\frac{1}{\omega}\int_{0}^{\infty}R_{ij}(t)\sin(\omega t)dt$?

The infinite frequency added mass calculated by BEMRosetta seems to be more accurate than that by WEC-Sim, especially in yaw direction. What optimization has BEMRosetta done in the calculation? Consider more frequency component?

Looking forward to your reply

Best regards,

Tianyuan

Issue with BEMRosetta Graphical Interface on Ubuntu

Hello everyone,

I'm experiencing an issue with displaying the graphical interface of BEMRosetta on Ubuntu, and I'm hoping someone could help me troubleshoot it.

Here's what I've done so far:

I downloaded and installed BEMRosetta on my Ubuntu system.
I followed the instructions in the README.md file by running the command "./theide".
Upon launching the application, I selected BEMRosetta to obtain the graphical interface, but it looks nothing like what I expected.
Here's a screenshot of the interface I'm getting:

I'm using Ubuntu, and I haven't encountered any specific errors when running the application.

Could you please assist me in identifying the problem and getting the correct graphical interface for BEMRosetta?

Thank you in advance for your help!

Crashes on loading hydrodynamic data in Windows 10

Hi!

Firstly, thank you for working on this amazing tool, it's helped me a lot.

I've been able to load meshes, manipulate and save them and have used the BEM Solver to produce the relevant files to run NEMOH which I've done successfully.

However, when I try to load the hydrodynamic data by opening the Nemoh.cal file, BEMRosetta abruptly closes after starting the process. I initially thought it might be something to do with my Nemoh output files but the same behaviour is observed even if I try and load up the hydrodynamic data that's packaged with the distribution (BEMRosetta\examples\nemoh\ellipsoid\Nemoh.cal).

I'm running BEMRosetta by simply executing the .exe file in the bin folder. I'm running the latest version of Windows 10 and I've pulled the latest version of the repo.

I hope you can help.

Many thanks
Prash

During make on Linux

make: *** No rule to make target 'ScatterDraw/Unpedantic.h', needed by '_out/BEMRosetta/BEMRosetta_cl/GCC-Gcc-Linux-Main-Posix-Shared/main.o'. Stop.

[21042] Frequency 0.209000 not found

Dear Iñaki,

First of all thanks for your contribution at OpenOre. Basically you made exactly what i was needing!

Well, i have an AQWA file which i try to open in Rosetta but i get the following error:
[21042] Frequency 0.209000 not found

In the LIS file a frequency of 0.20944rad/s is defined, which refers to the 30s period. I don´t understand why rosetta is looking for the 0.209 frequency.

My intention was to open this AQWA generated file and save it into NEMOH or WAMIT format.

Kind regards

Roberto

BR-Wamit

Dear Iñaki,

1. Recently, i was testing BR with wamit outputs .1 and .2 files and exporting them to csv files
   My geometry is a hemisphere R=2.5 with gravity center =1.25 and ULEN=2.5.
   I was testing with ULEN = {1 , 2.5} and something is wrong with the scale

To fix it i had that ...
A= A * (rho/1000) * ulen^PowRad;
B= B * 100
Fe= Fe * (rho/10000) * grav * Aw * ulen^PowDiff;

As usual in the pitch case, PowDiff=3, PowRad=5, Aw=1 , grav=9.81 , rho=1025

Can you review these options in BEMRosetta? The idea is that at least it shows the exported csv as the original data output of wamit
I can transform them using code.

thanks

Only opens master on Windows computer

After download, following the instructions, it only opens as the master on U++ on my windows computer. Is there a way to get it to open the display file?

RAO estimation

Hi,
I am using Nemoh and BEM Rosetta for my work. I need to estimate the RAO of motion of a floating body in the frequency domain. I could see an option RAO in BEM Rosetta, but I am unable to click it when I am loading the Nemoh.cal file, even though I am getting the hydrodynamic coefficients. Is there anything I should do about this in the Nemoh?
Kindly help.

Unable to load WAMIT mesh of DeepCWind platform

Dear @izabala123 ,

I would like to visualize the input mesh of the OC4 semisubmersible platform. However, since I don't have a WAMIT license, I rely on the BEMRosetta software. When I try to load the .gdf file, I get the following error (see screenshot below).

I downloaded the input files (WAMITInputFiles_OC4Semi_2nd.zip) from this NREL forum topic

Have you seen this error before?
I would appreciate your help

Best,

Converting Nemoh output with Python

Dear @izabala123 ,

For my master thesis, I am using OpenFAST and Nemoh in the loop to simulate various floating platform designs for offshore wind application, with Python. I use the pyfast toolbox from OpenFAST, and I've converted the Nemoh matlab wrapper to a Python version, which I've adjusted slightly to suit my own needs.

To use the hydrodynamic coefficients in OpenFAST's HydroDyn module, I need to convert the Nemoh output files to WAMIT .1, .3 and .hst format. I understand that this is possible with BEMRosetta; however I need to do it inside a Python loop, so I can't be using a GUI.

What are the possibilities for this with BEMRosetta, and what would be the best approach?

Awaiting your kind advice,

Bart Klootwijk

Question on the transfer of QTF results in multiple headings to WAMIT format

Hi @izabala123

In BEMRosetta, when exporting QTF results of multiple headings to WAMIT, there are three options to choose: all headings, all headings without crossed and selected heading saved as 0°. I tried the first two options, but both of the transferred results caused errors in OpenFAST.

If "All headings" is chosen, the results will cause the following error in OpenFAST:

If "All headings without crossed" is chosen, the results will cause the following error in OpenFAST:

I put the two kinds of results in the attachment.

I'm not sure whether this problem is caused by BEMRosetta or OpenFAST. Do you have any ideas?

Thanks

AllHeadings.zip
AllHeadingsWithoutCrossed.zip

about RAO

Hi,
I use the same mesh file to calculate the RAO both in the HAMS and Nemoh v3. And the mass matrix and the restore matrix in HAMS is calculated by the WAMIT_MeshTran.exe. And the inertia matrix and kh.dat is calculated by the Hydroscal.exe in Nemoh. But the result in HAMS is much smaller than it in Nemoh. And it seems that the result in Nemoh is accurate.

Could you tell me that what the difference between the HAMS and Nemoh when calculating the RAO. Is the mass matrix in HAMS and the inertia matrix?

By the way, when i click the RAO in the process in the BEMRosetta, the result by BEMRosetta is also different from the Motion file by Nemoh.

Thank you.

Export drift forces from AQWA to WAMIT

Good afternoon!
Is it possible somehow to include drift forces to WANIT .out during the conversion of AQWA results to the WAMIT output file? I want to include drift forces in my time-domain calculations in WEC-Sim software but WEC-Sim can read drift forces only from WAMIT. I calculated the BEM problem in AQWA and tried to convert AQWA results to the WAMIT .out file using BEM Rosetta. But the final .out file does not include drift forces calculated in AQWA.
I attach my AQWA results here
Analysis.zip

Windows Version

Hello, thank you very much for the work done on this nice tool.
For some reason, it quit working, and after downloading the latest executables and 'dodging' the A/V warnings, it still does not launch at all. Could you suggest how to make it work again? Thanks!

Phase invertion QTF from AQWA to WAMIT

Hello!

first of all thanks for this nice work!

I have one question( potentially bug?) regarding the import and export of AQWA data.

When exporting data from AQWA to WAMIT , I have seen that the linear excitation phases are changed ( - ) . I believe this is because the different wave definitions in the two codes.
But then when exporting 12s and 12d files from AQWA QTF data, I think the phases are not being inverted by the code . Is that the case - is there a reason for that or is it potentially a bug ?

Many thanks in advance!
Armando

Import results from Capytaine

Good afternoon! I have a problem when trying to open .tec results from Capytaine.
I try to compare results calculated in AQWA and Capytaine. AQWA results were imported without any problems.
When I tried to import Capytaine results (.tec files) I obtained error, that results have to be located in "results" folder. Then I moved my files to "results" folder and got an Error "Nemoh.cal can't be found". After that, I used "BEM Solver" to generate all solver files for Capytaine from AQWA files and then copied my .tec files to "results" folder. Finally I got an Error:
Error: [File: 'C:\Users\dadid\Documents\August Explorer\Working folder\BEM comparison\Test\Results\RadiationCoefficients.tec', line: 614]: No data available
Please help me to resolve this issue. I attached necessary files.
Test.zip

Aqwa to WAMIT output for Openfast error !

Hello Iñaki,

I was trying to export results from Aqwa to wamit output files for using with openfast. I encountered the following error while running openfast. Have you even come across this error? Do you know how to solve this? Is it possible to solve this error using the newly added processing features of BEMRosetta ?

Regards,

Rahul.

Can it read the .out file expoted from Hydrostar?

Dear @izabala123

Hydrostar can also exported the wamit type output file, while it can not read the output file from hydrostar. Can it read the wamit type output file from hydrostar?

Best regards,