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-   -   HELP! UDF sinusoidal wave, VOF model, porous face! (https://www.cfd-online.com/Forums/fluent/32957-help-udf-sinusoidal-wave-vof-model-porous-face.html)

A8anato_psofimi February 3, 2004 13:00

HELP! UDF sinusoidal wave, VOF model, porous face!
 
Hello, I am testing a wave absorbing beach in Fluent and have created the mech in Gambit. I need to calculate the effectiveness of the beach by finding the reflection coefficient. It is a 2D model, and the beach is modelled as a permeable face.

I have the following problems: -I need to define a sinusoidal wave going down the tank simulating a wave maker. Do I have to use a UDF for this? How much C programming knowledge do I need (I have virtually no programming knowledge)? How is this done?

-Also, how difficult is it to define a VOF for the surface of the water (water/air interface)? I dont know much about VOF, so I would like to know if the water depth is defined in Gambit by using 2 different meshes/faces for the water and air, or is the height somehow defined in the VOF operations, and how?

-Can anyone help me with the definition of the porisity of the beach? I have calculated the permeability, and that is all I have for the beach as far as numbers go (other than the geometry)

mateus February 4, 2004 02:49

Re: HELP! UDF sinusoidal wave, VOF model, porous f
 
Hi!

To get a feeling about VOF model go to the fluent documentation (vof modelling tutorial). I principle you can patch the fluid (water) zone in fluent, so you don't need to consider that when you're making your mesh. The sinusoidal wave might be a problem...I've tryed this with no succes. The initial condition, meaning the initial position of the water that you determine in fluent, can only tahke the form of circle, sphere, or cube or rectangle - sadly enough not a function as sine. Maybe you can do this with udf, or make 2 zones in gambit. Check out some papers on "dam break simulation" - there's a lot of stuff on the internet..

regards

MATEUS

ekakavand November 10, 2009 14:42

hi

I should model wave ocean with fluent, and i am not sure that i can model path ocean wave with vof algorithm or not? because in fluent help is written that we can not model streamwise periodic flow with vof algorithm.

thank you,
best regards,
elahe


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