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-   -   generate Waves in openfoam (https://www.cfd-online.com/Forums/openfoam/66544-generate-waves-openfoam.html)

gautami September 17, 2009 11:55

Hello Mr Gschaider,

Thank you.
I think I will first try to understand and work with the distorted Cone example, and then I will implement it for the wave tank.

In your reply you said “But you should try to "go to" point values as early as possible to avoid interpolation artifacts”. I am sorry I did not understand this sentence. If you don’t mind can you please explain.

Thank you,
Gautami.

gschaider September 17, 2009 17:08

Quote:

Originally Posted by gautami (Post 229786)
Hello Mr Gschaider,

Thank you.
I think I will first try to understand and work with the distorted Cone example, and then I will implement it for the wave tank.

In your reply you said “But you should try to "go to" point values as early as possible to avoid interpolation artifacts”. I am sorry I did not understand this sentence. If you don’t mind can you please explain.

Try to achieve the same stuff using the pts() and the pos() function, think about why the pulsed-Demo-Case only gets the right parabolic profile using pts() and you will understand

Schag September 18, 2009 05:10

Hello,

thank you for the topic, it was really useful for my work on waves.
Maybe it was said before and I didn't see it, but using movingCone AND interDymFoam, but not groovyBC, I don't manage to modify the movingWall velocity.
Is there a way to modify it directly with the solver? I cannot find the name of the object pointMotionU in interDymFoam, so I cannot modify it. Anyone can help me please? I just miss this variable name.

Thanks a lot,

Regards,

Julien

gautami October 20, 2009 11:07

Hello Mr Gschaider,

At last I could model a wave tank with a piston type wave maker in InterDyMFoam using groovyBC.

Thank you very much for your guidance and prompt replies.

Thankyou,
Gautami.

nbyjn November 19, 2013 01:45

Hi Niels:
I'm really want to know what do you mean by "the number of gamma evaluations per timestep needs to be 1" and how to set for this?

Thank you!

premal August 7, 2014 08:52

Can any one tel me how can i generate wave in OpenFoam?
 
Hello,

I read all threads but still not understand how to generate waves in OpenFoam and links given in this thread is not working so can anyone please provide me.

Can i generate waves in shallowwater Foam? if yes then please let me know

Thanks in advance

Regards,
Premal Sheth
Senior research Fellow

vitor.geraldes@ist.utl.pt January 9, 2015 17:45

waves with groovyBC
 
I managed to simulate nice waves using the following boundary conditions together with a solver that takes into account buoyancy:

file pointmotionU:

outlet
{
type groovyBC;
value uniform (0 0 0);
valueExpression "toPoint((U&normal())/(normal()&vector(0,0,1))*vector(0,0,1))";
}

file U:
outlet
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}

file p_rgh:
outlet
{
type prghPressure;
p uniform 0;
}

I have obtained nice waves, but the solver required very small time steps. The problem seems to be in the fact that the mesh is changed explicitly between time steps.

chia87 November 15, 2016 22:16

Hi all,

I'm doing a similar project with the thread starter, on breaking waves.

I'm trying to use the 'focussed waves method' to generate a breaking waves.
I did managed to generate a breaking wave in real life experiment, however when I tried to duplicate it in OpenFOAM, I found out that when I tried using combinedWaves with a varying phase to generate breaking wave,

I encountered some problems with the phasing as OpenFOAM would reduce all phase shift to < 2pi.

Hence i'm trying to input TSoft and phase shift for all my wave components to achieve the desired breaking waves,
---------------

I would also love to use the (displacement vs time history) of the piston strokes to produce the same results as I got for my breaking wave experimental work,

However my displacement vs time history of the piston is very irregular (since it involves as much as 28 waves components), any idea how I advance from here?

Any inputs appreciated!

Thanks,
Chia

Phicau November 15, 2016 22:50

Hi Chia,

no idea about the combinedWaves issue, but for generating a wave focussing (or any other waves) with time series from a piston wavemaker check olaFoam:

https://www.youtube.com/watch?v=WF9zKCgsx5w
https://github.com/phicau/OLAFOAM

Best,

Pablo

ngj November 16, 2016 01:22

Good morning Chia,

The generation of focussed waves can be done with the irregular wave type, where you should choose focusing rather than random wave phases:

https://openfoamwiki.net/index.php/C...hasing_Methods

You can also use OceanWave3D to use your steering signal and couple with waves2Foam with the dedicated method. OceanWave3D has much better propagation properties, because of better discretization. There is a tutorial in waves2Foam on the coupling of these models.

Kind regards

Niels

chia87 November 16, 2016 01:48

Thanks all for the reply,

Hi Niels,
I'm actually using the focussing of multiple regular waves for achieving a focussed wave. The chosen wave frequencies are arbitrary, I'm not using any specific spectrum. (had done experimental work using focussed regular waves packages)

Guess i'll look directly at the Oceanwaves3D for inputing the piston signals,

thanks again!

Chia


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