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-   -   slip boundary condition (http://www.cfd-online.com/Forums/openfoam-solving/109426-slip-boundary-condition.html)

ammm November 17, 2012 06:43

slip boundary condition
 
hello all
i want to simulate a microchannel and i want to set slip velocity for it.
slip velocity in wall:
http://upload.iranvij.ir/images_aban...1727938328.jpg

how can i set this condition for wall?
do i use moving wall or specified shear?which one?or i should write a udf?

i have another question too. i want to set adhesion and surface tension for my model what should i do?i have one phase in my model and three reaction happen in it.
thanks in advance
i am waiting for your helps

michielm November 18, 2012 06:18

1) The closest BC to the slip BC is the partialSlip condition, which mixes the no-slip and the zeroGradient condition. You could take a look and see if it works for you.
Otherwise you will indeed need to implement it yourself. Another user here is trying a similar thing.

2) if surface tension and adhesion (I assume you mean the contact angle) are important in your simulation that means you have (at least) a two-phase system so I don't get your comment that you have 1 phase?!

If you indeed have two phases, the most suitable solver is probably interFoam with which you can set the surface tension in constant/transportProperties.

The contact angle is a boundary condition. The most simple one is the constantAlphaContactAngle, in which you just set a fixed angle at the boundary patch. There is also a dynamicAlphaContactAngle which allows you to specify a velocity dependent contact angle.

Cheers,

Michiel

ammm November 18, 2012 09:06

thank you for your help michiel


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