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Release of a Wave Generation and Absorption Toolbox for OF

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Old   April 14, 2015, 15:34
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  #41
ngj
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Niels Gjoel Jacobsen
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Dear all,

I have now streamlined the code in setWaveProperties related to irregular waves (as of revision 2066). This means that I have removed code duplication, but also that the interface for irregular waves is slightly changed.

Instead of the old interface, it is now necessary to add the following subDict to the waveProperties dictionary, e.g. immediately prior to the definition of the relaxation zone:

Code:
    frequencyAxis
    {
        writeSpectrum true; // false = default value

        discretisation cosineStretchedFrequencyAxis; // equidistantFrequencyAxis;

        //lowerFrequencyCutoff 0.1;
        //upperFrequencyCutoff 2;
    }
There is no functional change in the execution of the program, i.e. the frequency discretisation is unchanged and the default values of the lower and upper bounds are still 0.3fp and 3.0fp, where fp is the peak frequency.

The flag

Code:
discretisation equidistantFrequencyAxis;
is identical to

Code:
equidistantFrequencyAxis on;
and the flag

Code:
discretisation cosineStretchedFrequencyAxis;
is identical to

Code:
equidistantFrequencyAxis off;
I am sorry for the inconvenience, but these changes will eventually become clear.

Kind regards,

Niels
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Old   July 12, 2015, 07:54
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  #42
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Niels Gjoel Jacobsen
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Good afternoon,

With a few modifications the source of waves2Foam now compiles under OF2.4.0 and the solver waveFoam is also created. The solver porousWaveFoam is to be added at a later stage.

Disclaimer: I have only tested the waveFlume tutorial and it executes. I have not validated the correctness of the wave propagation in OF2.4.0.

The commit is svn-revision 2072.

Furthermore, the OF-versions OF-1.6-ext, OF-1.7, OF-1.7.1 and OF-2.0 is no longer being tested, when modifications are made to waves2Foam. This does not explicitly mean that the code will not compile. See the following section on the wiki: http://openfoamwiki.net/index.php/Co...Versions_of_OF

Kind regards,

Niels
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Old   September 9, 2015, 10:26
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  #43
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Niels Gjoel Jacobsen
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Dear all,

I have made an update to the solvers (waveFoam and porousWaveFoam), so they now take an additional parameter in the waveProperties(.input) file:

Code:
seaLevelAsReference false/true;
This keyword is requested, whenever 0 < |seaLevel|. The effect is that the sea level is used as the vertical reference for the simulations (is set to true). This only affects these two lines in any solver in createFields.H:

Code:
volScalarField gh("gh", g & (mesh.C() - referencePoint));
surfaceScalarField ghf("ghf", g & (mesh.Cf() - referencePoint));
If seaLevelAsReference is set to false, the referencePoint is given a value of (0 0 0), i.e. the solution will be identical to the present day results.

The changes are committed as revision 2078.

Testing - Setup:
This implementation has been tested on the waveFlume tutorial, where the sea level was given 5 different values: [-0.1 -0.05 0.00 0.05 0.10]. Besides this, the waveProperties.input file was the same. The mesh was translated vertically according to the sea levels, such that the water depth remained 0.4 m. The translation was performed with:

Code:
transformPoints -translate "(0 X 0)"
The simulations were performed in foam-extend-3.1.

Testing - Results:
Four quantities were investigated:
  • The value of the time step throughout the simulation;
  • The variation of the surface elevation at x = 10 m as a function of time;
  • The variation of the rms value of the surface elevation as a function of x;
  • The pressures at the atmosphere and bottom boundaries for t = 20 s.
The surface elevation was corrected for the value of the sea level.



All 5 simulations (5 values of the sea level) yielded identical results. This is taken as a full validation of the implementation.


Please report any issues that you might have with the modifications of the solvers, compatibility with non-tested (pressure) boundary conditions.





Kind regards,


Niels
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Old   September 24, 2015, 14:59
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  #44
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Niels Gjoel Jacobsen
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Dear all,

wavs2Foam is now close to 4 years old (as open-source) and I would like to get to know you, the users, a little bit better. Therefore, I have made a Google Form with a few questions. I would appreciate a lot, if you could fill out the form and also circulate it to your colleagues and collaborators, who might not have seen this notice.

The form is found here:

http://goo.gl/forms/tvVIHGnNP9

I would like to use the opportunity to also inform you on the up-coming course in detailed numerical modelling of free surface waves that we are providing at Deltares. The full description can be found here:

http://www.dsd-int.nl/training/waves...surface-flows/


Thank you,


Niels
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Old   October 15, 2015, 15:21
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  #45
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Niels Gjoel Jacobsen
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Dear all,

It is my utmost pleasure to be able to announce that waves2Foam now has been extended with a coupling to OceanWave3D ([1]). This coupling has existed for a while in a less than generic form, but it has now been streamlined with waves2Foam. The coupling has already been described in [2].

OceanWave3D is an accurate and fast nonlinear potential wave solver, so the coupling will allow for
  • Faster generation of irregular waves
  • Generation of nonlinear irregular waves
Besides the coupling itself (see external wave theories and corresponding files for setting of the wave properties) the following are provided:
  • Install scripts that collect OceanWave3D from github and install OceanWave3D along with its dependencies. Additional requirements for waves2Foam are now gfortran and git.
  • A new tutorial called 'couplingOceanWave3D'
  • A memo that describes the control of the new coupling, see the directory 'doc'. Please read this document carefully, since there are some important subtleties to keep in mind. Furthermore, since waves2Foam now depends on an important third party contribution, please do pay notice to the suggested phrasing of references to all relevant contributors.
I hope that you all will enjoy this new extension.


Kind regards,

Niels


[1]: Engsig-Karup, AP, Bingham, HB, Lindberg, O. (2009). An efficient flexible-order model for 3D nonlinear water waves. Journal of Computational Physics, 228, 2100-2118.
[2]: Paulsen, BT, Bredmose, H and Bingham, HB (2014). An efficient domain decomposition strategy for wave loads on surface piercing circular cylinders. Coastal Engineering, 86, 57-76.

EDIT:

The coupling will be presented as part of the coming course in detailed wave modelling:
http://www.dsd-int.nl/training/waves...surface-flows/
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Last edited by ngj; October 16, 2015 at 03:02.
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Old   November 23, 2015, 02:36
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  #46
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Niels Gjoel Jacobsen
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Good morning all,

I am happy to announce that the cross-version compatible version of waves2Foam for OpenFoam-3.0.0 is now available. This includes a solver for waveFoam as well.

The free surface solver has become rather complex as of version 2.4, which means that it will require some time to figure out, how to include porosity effects correctly in the solver. No attempts will be made with respect to that in the near future.

Please make note that even though the code compiles, this does not mean that a rigorous validation for waves in OpenFoam-3.0.0 has been performed. The users are hence encouraged to performed such validation steps on their own.

Kind regards,

Niels
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Old   April 4, 2016, 09:13
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  #47
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Niels Gjoel Jacobsen
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Dear all,

Today, I have made a small modification to the third-party dependencies. Now, waves2Foam is being link to a different fork of OceanWave3D. This fork is almost identical to the previous one, but there are subtle differences:

1. The new fork still undergoes continued developments, where the old fork was at a 'dead end';

2. There were some bugs in relation to the wave generation with the a wave paddle signal. These bugs are now resolved with an effort from the original developers from the Technical University of Denmark.

Otherwise, no functional changes to the code and compilation should be smooth.

This message concerns revision 2091.

Kind regards,

Niels
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Old   July 1, 2016, 16:51
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  #48
ngj
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Niels Gjoel Jacobsen
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Dear all,

waves2Foam has now been made compatible with OpenFoam-4.0.0. There have been introduced quite some changes with OpenFoam-4.0.0, which means that the sampling-library was not successfully adapted to the syntax in OpenFoam-4.0.0.

The lack of a waves2Foam sampling library means that the two run-time sampling methods:

- surfaceElevation
- overtopping

are not supported for OpenFoam-4.0.0.

The solver porousWaveFoam still needs to be created for OpenFoam-4.0.0.

The tutorial waveFlume has been executed, and a visual inspection of the results appears to yield similar results. Though, without the surfaceElevation tool, it is not possible to perform a validation against prior versions.

Users are strongly encouraged to perform their own validation, if OpenFoam-4.0.0 is adopted.


Kind regards,

Niels
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