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wave maker modeling

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Hi, dear all,

I am trying to model the wave generation in a rectangular tank by a piston wave maker. I just make a rectangle domain in the geometry, and set a side wall as " moving wall" boundary condition (make it cyclic move in horizontal direction). At the same time I use both "laminar flow" and "moving mesh" interface, and do a time dependent analysis. But it does not converge.
I suspect maybe the geometry I made is fixed (100m x 10m), but when I set the piston wave maker is "moving wall", it changes the geometry a little bit, but I am not sure, the COMSOL is supposed to deal with it by itself. Any advice? Thanks.

Jinfu Xiao

2 Replies Last Post 21.06.2014, 08:06 GMT-4
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Hello Jinfu Xiao

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Posted: 1 decade ago 20.06.2014, 21:13 GMT-4
Hi Jinfu,

Have you figure out this problem? I am also interested in simulating the wave. I have seen many comsol paper has generated the wave. But I don't know how they make that. Can I have your email address? We can discuss the problem together.



Best,


Ting
Hi Jinfu, Have you figure out this problem? I am also interested in simulating the wave. I have seen many comsol paper has generated the wave. But I don't know how they make that. Can I have your email address? We can discuss the problem together. Best, Ting

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Posted: 1 decade ago 21.06.2014, 08:06 GMT-4
Ting,

Actually I don't work on this problem anymore. But I can give you some clue based on my experience. Generally there are two ways to generate the wave by numerical method.
1. virtual free surface (defining the geometry or pressure boundary condition on the free surface, I have done this successfully. however this is not true when there is a structure in the water domain, which will definitely change the wave surface due to the obstacle effect, while I still define a perfect regular wave surface)
2. volume of flow method (this is a more realistic way to model the wave, like a wave generator, the wave propagates from one side to another side, this method can account a more accurate fluid-structure interaction in my opinion. I didn't know this method until recently I went to a ocean conference (OMAE) and talking to the people working on this area, really learnt a lot. But I didn't try this method and don't have much knowledge about using it in COMSOL.)

I suggest you search more about the "volume of flow method" and cross-reference with "COMSOL", maybe you can find more info about it. I do find a paper maybe helpful, which is attached.

Anyway good luck! if you finally works this out, please let me know, I am still interested.

Regards

jinfu
jxiao3@ncsu.edu
Ting, Actually I don't work on this problem anymore. But I can give you some clue based on my experience. Generally there are two ways to generate the wave by numerical method. 1. virtual free surface (defining the geometry or pressure boundary condition on the free surface, I have done this successfully. however this is not true when there is a structure in the water domain, which will definitely change the wave surface due to the obstacle effect, while I still define a perfect regular wave surface) 2. volume of flow method (this is a more realistic way to model the wave, like a wave generator, the wave propagates from one side to another side, this method can account a more accurate fluid-structure interaction in my opinion. I didn't know this method until recently I went to a ocean conference (OMAE) and talking to the people working on this area, really learnt a lot. But I didn't try this method and don't have much knowledge about using it in COMSOL.) I suggest you search more about the "volume of flow method" and cross-reference with "COMSOL", maybe you can find more info about it. I do find a paper maybe helpful, which is attached. Anyway good luck! if you finally works this out, please let me know, I am still interested. Regards jinfu jxiao3@ncsu.edu

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