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-   -   I want to simulate a Wave in the flume (http://www.cfd-online.com/Forums/flow-3d/83520-i-want-simulate-wave-flume.html)

mfeizbahr January 2, 2011 08:01

I want to simulate a Wave in the flume
 
I want to simulate a Wave in the flume..
how should I define boundary conditions ?
I mean in which direction should I define Flow?

MuxaB January 17, 2011 02:39

wave are always defined at the x or y mesh boundaries, i.e., vertical boundaries. Designate a mesh boundary a wave boundary, set the initial fluid volume in the domain using fluid height, use the same height at the wave boundary, set the wave length and amplitude - and you are good to go.

mfeizbahr January 17, 2011 05:27

Tnx a lot for help..
but.. what do u mean by : " wave are always defined at the x or y mesh boundaries .. "
you mean there is no mesh need for Z direction ?

MuxaB January 19, 2011 01:45

Quote:

Originally Posted by mfeizbahr (Post 290700)
Tnx a lot for help..
but.. what do u mean by : " wave are always defined at the x or y mesh boundaries .. "
you mean there is no mesh need for Z direction ?

No, mesh should be defined in all three directions. What I meant is that in FLOW-3D surface wave generators are implemented as mesh boundary conditions and can be applied at any of the four mesh boundaries, xmin, xmax, ymin or ymax.

mfeizbahr January 19, 2011 06:20

thank you for informations.

fortunately after all I simulated the wave but there is another problem I faced, is the water dept decrease gradually .
I chose X min ( LW ) but really i don't know what should I choose for X max ?
in case of " continuative " the water dept decreased gradually.
in case of " Symmetry " water turn back after it reach to the end of mesh.

can u help me with that ?
i need no decrease in water dept and continuant wave for example like a seaside.

stefmascio January 19, 2011 10:38

choose the "Outflow" b.c. with the option "Allow fluid to enter...".

mfeizbahr January 20, 2011 04:55

thank you Stefmascio...

but there is still dept decreasing.. :(

mfeizbahr January 22, 2011 00:50

Dear Stefmascio...

When I did your suggestion for choosing the "Allow fluid to enter...” after running simulation the water dept start decreasing gradually and suddenly after 20 sec, new stream started coming into the flume with reverse direction, interfacing the waves and the incoming fluid cause an overtopping the water depth…
so this suggestion might not be a proper solution....
do u have any other idea ?

bejewel January 22, 2011 21:43

Model Setup\ Numerics\Wave boundary conditioon
then to choose:
Eliminate net volume flux at wave boundary,or
Include net volume flux at wave boundary.

good luck!

mfeizbahr January 23, 2011 03:08

Dear Bejewel ...

there is no " wave boundary condition " in Numerics ....
and really I could not fined any of your suggestions there....

thank you any way :)

Ghirghidov January 24, 2011 05:58

Dear mahdi,

Try to change mesh resolution.

Regards.

bejewel January 25, 2011 11:04

Flow-3D 9.4---> " wave boundary condition " in Numerics


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