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Hello, I'm a new user of the Artemis module.
I would like to model the effects of a floating breakwater. I already charaterised it in terms of reflection and transmission coefficients (and total dissipation), as function of the wave frequency.
From my understanding there is no direct way of specify this kind of input.

Any suggestion on how to proceed?
A vague idea came to me reading this paper:
www.witpress.com/elibrary/wit-transactio...-environment/30/7660
similarly to equation 5 it seems to me that is would be possible to define a dissipation (µ*) field (in the mesh zone where the breakwater is located) for accounting the transmission effects of the breakwater:
µ*=1/B [1-k_t²(f)]
(B is the breakwater width, and k_t(f) is the transmission coefficient, function of the frequency f).
Do you think this to be a viable solution?
I read that for similar problems some approaches have been tried,
www.opentelemac.org/index.php/kunena/art...nsmissive-structures
but they seem to me not a definitive solution.
Best regards
Michele

Hello Michele,

I just read your comment because I was looking the answer of how modeling a floating breakwater. Have you tried this equation in artemis ? And how do you insert this equation in artemis code?
Thank you for your answer,

Camille

Hello Camille,
yes I tried to use this simplified approach. I had to "tune" the equation in order to get reasonable results: see attached image



It is sufficient to add this term to the dissipation field on the mesh nodes that correspond to the breakwater (at the end of subroutine calcmu.f, just before the "return" statement).
The mesh should be fine enough (i.e. sufficiently finer than the breakwater width).
In the attached image is shown a preliminary example. I considered a wave field from left to right (H=0.5 m T=2.5s) with free exit at the right boundary. If I insert a breakwater between X=42 and X=44 (i.e. width B=2 m) with transmission coefficient 0.5 I obtain a transmitted wave Ht=0.276 m (i.e. Ht/H is about 0.55 the incident) and a reflected standing wave.

Regards
Michele

Hello Michele,

Thanks a lot! we can see that it worked, it will be very helpful .
I will test it.

Grazie mille,

Camille