[Phicau]

Hi Han,

again, porosity does not have anything to do with your problem, it needs to be removed. Then you can modify snappyHexMeshDict to use core.stl or any stl file instead of caisson.stl.

Pablo

[mhanis38]

Dear Pablo,

After finish running the simulation, I got some weird result on the paraview as figure attached.

Seems it like the water was absorbed and at the same time it generate wave from the vertical wall.

May I know why the result can be like this ?

Thank you.

Kind regards,
Han

[Phicau]

Hi Han,

you should check carefully your boundary conditions, mesh quality and cell resolution near the wall.

Best,

Pablo

[helenxing]

Hi Pablo,

I am new in using OLAFOAM and trying to simulate wave current interactions. I found that the wave length change is captured very well when an opposite current is applied to the waves. But the current effect on wave height is not captured ( under no breaking condition)? If increases the current speed, wave breaking is not captured neither. Any tips?

[kenneth0811]

Dear helenxing and OLAFOAM user.

I am also a OLAFOAM user and I am studying the interaction wave-current-submerged breakwater. I compared that Umeyama(2011)'s experiment to vertify the validity of the wave-current interaction of OLAFOAM.
I taged two figure that compared with Umeyama(2011)'s experiment.

I do not know if this reply will help you, But I hope you can refer to it.



Umeyama, M. (2011). Coupled PIV and PTV measurements of particle velocities and trajectories for surface waves following a steady current, Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, 137(2), 85-94.

[Phicau]

Dear users,

due to naming issues olaFoam is now olaFlow ( Releasing olaFlow ), therefore, I encourage you to use the new version for which I will be releasing new features and enhancements soon. The only change that you will notice when using olaFlow is that the solvers are called olaFlow and olaDyMFlow instead of olaFoam and olaDyMFoam.

Hi Helen,

at this point I am still developing the wave-current interaction part. It is great that you noticed this, I will check on it and will release future updates in the olaFlow project.

That is a remarkable agreement Ju Hyun Bae, thanks for sharing!

Best,

Pablo

[helenxing]

Ju Hyun Bae, thank you for your sharing

[helenxing]

Hi Pablo,

Thank you for your reply. Looking forward to the updates !

[Lewis Liang]

Dear Pablo,

I have been learn to use OLAFoam by myself for some time. And I plan to build up a case of 3D wave tank with multiple inlet, like two separate regular wave propagating with angles. To do this, one is need to modify the waveDir as well as the absDir in constant/waveDict. Next, it is need to modify the waveAlpha in 0.org/alpha.water. However, the initial parameter of each inlet is read from the only waveDict file in constant folder. It seems that set-up of multiple inlet here is not working. So, for this situation, how can I fix this problem?

Thanks in advance!

Cheers!

Lewis

[Phicau]

Hi Lewis,

thanks for using olaFoam. As you may know, olaFoam is now called olaFlow, so I suggest that you switch to the new version, as all new developments will be released there:

https://github.com/phicau/olaFlow

Regarding your question, olaFlow (and olaFoam before) is ready to handle multiple inlets, just change the name of the dictionary for each one, e.g.:

inlet1
    {
        type            waveAlpha;
        waveDictName    waveDict1;
        value           uniform 0;
    }
inlet2
    {
        type            waveAlpha;
        waveDictName    waveDict2;
        value           uniform 0;
    }

Let me know if this is not working as intended.

Best,

Pablo

[Lewis Liang]

Originally Posted by Phicau

Hi Lewis,

thanks for using olaFoam. As you may know, olaFoam is now called olaFlow, so I suggest that you switch to the new version, as all new developments will be released there:

https://github.com/phicau/olaFlow

Regarding your question, olaFlow (and olaFoam before) is ready to handle multiple inlets, just change the name of the dictionary for each one, e.g.:

inlet1
    {
        type            waveAlpha;
        waveDictName    waveDict1;
        value           uniform 0;
    }
inlet2
    {
        type            waveAlpha;
        waveDictName    waveDict2;
        value           uniform 0;
    }

Let me know if this is not working as intended.

Best,

Pablo

Hi, Pablo!

Thanks for your tips! It is working now.

I will switch to the new solver later on.

Cheers!

Lewis

[Lewis Liang]

Dear Pablo,

From the book Ocean Engineering Science 2005 (By Bernard Le MéhautéFor), In a plane flow (2D), a following current can reduce wave height and an opposing current tends to enlarge them.

Then I run 3 sets of two dimensional cases to study the effect of different kinds of current. I found my numerical data got a the opposite results compared with the above literature results.

For this question, is it due to some numerical set-up or other specific causes?

Thanks in advance!

Lewis

[spf521]

Originally Posted by ms411

Dear Pablo,
since a few weeks I am trying to simulate waves on a dike. I need your help. I read a lot of papers for similar cases. I think the boundary conditions are right and the mesh is the problem. I read in the cfd forum, that other people had the same problem, due to the orthogonality of the mesh. This was my first mesh with the following results: Picture 01 02
So I tried to create it with snappyHexMesh.There seems to be a problem with the inlet at first time step. So do you know where my fault could be? Picture 03 04

Do I have to change something in the fvschemes or in the fvsolution? I load the case in a dropbox. Would you be so nice and have a look on it, I really don't know what to do.
https://www.dropbox.com/s/68apuhz3yq..._case.zip?dl=0

Thank you very, very much and best regards.

Martin

Hi Martin,
The link is invalid, would you please add a new link? Because I met a similar problem, I was wondering if I can refer the settings in your case.
Thanks a lot!

[Phicau]

Hi Lewis,

I am extremely busy these days, I will take a look at it soon. Can you share your wave conditions?

Best,

Pablo

[Lewis Liang]

Originally Posted by Phicau

Hi Lewis,

I am extremely busy these days, I will take a look at it soon. Can you share your wave conditions?

Best,

Pablo

Dear Pablo,

I modify the case of currentWaveFlume into a case where there is an opposing current generating from the right (outlet) to the left (inlet), and my set-up is shown below:

(1)0.org/U

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.7.x                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    location    "0";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    inlet
    {
        type            waveVelocity;
        waveDictName    waveDict;
        value           uniform (0 0 0);
    }
    outlet
    {
        type            waveAbsorption2DVelocity;
        uCurrent        (-0.75 0. 0.);
        value           uniform (0 0 0);
    }
    bottom
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    atmosphere
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    frontAndBack
    {
        type            empty;
    }
}


// ************************************************************************* //

(2)constant/waveDict

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.3                                   |
|   \\  /    A nd           | Web:      http://www.openfoam.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      waveDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

waveType        regular;

waveTheory      StokesV;

genAbs          1;

absDir          0.0;

nPaddles        1;

waveHeight      0.10;

wavePeriod      3;

waveDir         0.0;

wavePhase       4.71238898;

uCurrent        (-0.75 0. 0.);

// ************************************************************************* //

(3)system/setFieldsDict

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.3                                   |
|   \\  /    A nd           | Web:      http://www.openfoam.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      setFieldsDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

defaultFieldValues
(
    volScalarFieldValue alpha.water 0
    volVectorFieldValue U           (0. 0. 0.)
);

regions
(
    boxToCell
    {
        box (-10 -1 -1) (30 1 0.4);

        fieldValues
        (
            volScalarFieldValue alpha.water 1
            volVectorFieldValue U           (-0.75 0. 0.)
        );
    }
);

I also upload the numerical results related to the cases involving non-Current, following-Current and opposing-Current in paraview for comparison. Those results seem right but I am not sure why my results of wave height is opposite with regard to conclusion by Bernard Le Méhauté (2005).

Thanks in advance!

Lewis

[hankshih]

Dear Pablo,

I want to simulate 2D 1/35 sloped ,wave condiction H=0.127 h=0.4 T=2,wavetheory stokesV,using k-epsilon model
I have modified the breakwater tutorial,wall boundary condiction used symmetry,other boundary condiction is unchanged.
Do you have some suggest to set maxAlphaco?I have tried to set maxAlphaco=0.3,but breaker data is wrong.
And sloped boundary condiction have some suggested?

Best regards,
hank

[Phicau]

Hi Hank,

wave breaking is a challenging process, especially running it in 2D, with air and turbulence modelling.

Without further data from your numerical setup and mesh I can only make wild guesses. Courant = 0.25 shall work, and usually the slope will have no-slip (fixedValue = 0) BC.

Best,

Pablo

[hankshih]

Dear Pablo,

I am so pleased for your reply.Thank you.

Numerical domain is 35m Length*0.02m Width*1m Height.
Blockmesh used
blocks
( hex (0 1 5 4 3 2 6 7) (1750 1 240) simpleGrading (1 1 ((0.5 0.5 0.5)(0.5 0.5 2))) )

I tried your tip to set maxAlphaco=0.25,but the slopes free surface elevation also wrong. Breaking point isn't conform Ting Ting and Kirby data(1994 Observation of undertow and turbulence in a laboratory surf zone).
Could you have some suggest to change another parameter? Or some I can try change it?

Slopes boundary condiction in case follow breakwater tutorials caisson BC is ok?

Best regards,
hank

[Phicau]

Hi Hank,

that is very little information to understand what is going on, so I cannot offer a best guess than what I mentioned in the previous post. You need to evaluate where is the error and why results are not as expected. For example, are wave conditions the same? Does the mesh shape or cell size affect propagation? How is turbulence affecting the case? CFD is all about going step by step from easy to challenging.

I also suggest that you take a look at this post: How to give enough info to get help and come back after you have pin-pointed the issues.

Best,

Pablo

[lincui]

Originally Posted by Lewis Liang

Dear Pablo,

From the book Ocean Engineering Science 2005 (By Bernard Le MéhautéFor), In a plane flow (2D), a following current can reduce wave height and an opposing current tends to enlarge them.

Then I run 3 sets of two dimensional cases to study the effect of different kinds of current. I found my numerical data got a the opposite results compared with the above literature results.

For this question, is it due to some numerical set-up or other specific causes?

Thanks in advance!

Lewis

Dear Pablo,
I have the same problem, any suggestion or command? thanks in advance.

Bests,
Lin