[blaise]

Dear all,

I am trying to generate a wave packet that resembles a set of component waves as used in a wave tank for the generation of a freak wave. I thought I could use the "waveType combinedWaves;" wave theory in waves2Foam combining waves of the same type with different heights and periods. Actually, the waves in the wave tank are Airy waves, which are not in the set of available wave theories in waves2Foam. Before I delve into programming this wave theory myself into waves2Foam, I just wanted to try this with a set of StokesI waves.

Question: Can the combinedWaves wave theory be used at all with a set of waves of the same type as described above?

The result of my trial can be seen in the attached image. This is of course not what one would expect to see. The fact that puzzles me most is that the waves are decaying. What could be the reason for that? Is the order in the list of wave names relevant?

The waveProperties.input file is attached.

Any hint is very welcomed!

Thank you and best regards,

Pascal.
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[ngj]

Hi Pascal,

You could try to read the manual about phases for irregular waves. Could be what you need.

Regarding the damping try to (i) gauge the theoretical surface elevation with the sampling tool based on the waveProperties file and (ii) try to refine the grid.

Kind regards

Niels

[blaise]

Originally Posted by ngj

Hi Pascal,

You could try to read the manual about phases for irregular waves. Could be what you need.
...

Hello Niels,

well, of course I did read the manual many times beforehand... I didn't understand that I can use the phase focusing on combined waves as well... that would be really nifty... just running a simulation with this...

Regarding the damping try to (i) gauge the theoretical surface elevation with the sampling tool based on the waveProperties file and (ii) try to refine the grid.

Kind regards,

Niels

Ok, using the sampleIncidentWaveField tool I get the attached diagram.
The decay does not occur primarily along the wave flume. When we look at e.g. the probe at 3.6m downstream, the damping occurs over time. It looks as if all the single wave components only get generated once, not repeatedly, doesn't it? But then again, there is the probe at 50m, which shows a completely different behaviour. I have no clue how to interpret all this. Any idea?

Thank you again and best regards,

Pascal.
--

[ngj]

Hi Pascal,

No, I meant that you should try e.g. JONSWAP with phase focusing. You can always implement your own spectral shape later.

What you see in the time series is probably some kind of correlation between all wave components. Notice that specifying phi=0 for all components is the same as focusing in x=0 and t=0.

Kind regards

Niels

[blaise]

Hi Niels,

I tried the JONSWAP phase focusing before, and it worked well, as far as I can tell.
Thank you for pointing out the effect of having a phase 0; now you say it its perfectly clear.

Thank you and best regards,

Pascal.
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[Narayan_UD]

Originally Posted by blaise

Hi Niels,

I tried the JONSWAP phase focusing before, and it worked well, as far as I can tell.
Thank you for pointing out the effect of having a phase 0; now you say it its perfectly clear.

Thank you and best regards,

Pascal.
--

Hi all

How can I generate two waves one after another with a time gap of 5 sec?

[ngj]

Hi Narayan,


Please follow these instructions for asking questions: Guide: How to ask a question on the forums


Furthermore, do read the waves2Foam manual as it should provide guidance. If your problem is not covered, you need to do some coding yourself.


Kind regards


Niels

[BeigeFoods]

Originally Posted by blaise

Hello Niels,

well, of course I did read the manual many times beforehand... I didn't understand that I can use the phase focusing on combined waves as well... that would be really nifty... just running a simulation with this... pickleballsplay


Ok, using the sampleIncidentWaveField tool I get the attached diagram.
The decay does not occur primarily along the wave flume. When we look at e.g. the probe at 3.6m downstream, the damping occurs over time. It looks as if all the single wave components only get generated once, not repeatedly, doesn't it? But then again, there is the probe at 50m, which shows a completely different behaviour. I have no clue how to interpret all this. Any idea?

Thank you again and best regards,

Pascal.
--

Hello Niels,

Thank you for your detailed explanation. It’s interesting to learn about your findings on phase focusing on combined waves and the damping behavior observed in your simulation. The behavior of the probe at 3.6m downstream and at 50m indeed seems puzzling. I’m afraid I don’t have a clear interpretation for this at the moment, but I encourage you to continue exploring and experimenting. Your work is very insightful!