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-   -   How to set slip velocity and temperature jump (http://www.cfd-online.com/Forums/cfx/100392-how-set-slip-velocity-temperature-jump.html)

awuunity April 24, 2012 23:40

How to set slip velocity and temperature jump
 
Hey friends:
I am dealing with microchannel heat transfer in CFX,but i dont know how to set up slip velocity and temperature jump boundary condition . I choose finite slip wall,but i dont know how to set slip modal and wall velocity.I am new to CFX.

Thanks for any possible help.

ghorrocks April 25, 2012 07:48

In CFX you can only have no slip walls or specified shear stress. There is no finite slip built in. You will have to derive it yourself and impose it as an expression (hopefully as CEL) on either a no slip wall (with wall motion presumably) or a shear stress wall.

awuunity April 25, 2012 21:19

slip velocity
 
Quote:

Originally Posted by ghorrocks (Post 356878)
In CFX you can only have no slip walls or specified shear stress. There is no finite slip built in. You will have to derive it yourself and impose it as an expression (hopefully as CEL) on either a no slip wall (with wall motion presumably) or a shear stress wall.

Dear ghorrocks:

Thank you for your help. But I still don't fully understand. How can i use CEL to simulate velocity slip?What should i edit in CEL?That would be the best for you give me a example.
Best regard

awuunity
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ghorrocks April 26, 2012 06:04

You have to know the mathematics of what you want to implement before you can implement anything. What is the mathematics of what you want to apply?

awuunity April 26, 2012 08:05

Quote:

Originally Posted by ghorrocks (Post 357152)
You have to know the mathematics of what you want to implement before you can implement anything. What is the mathematics of what you want to apply?

Dear ghorrocks:

Thank you for your help.I want to simulate water flows through tube and the tube's diameter is 0.01mm, length is 2mm. tube's outer surface temperature is 333.15K.The velocity of inlet set to 0.1m/s,temperature set to 293.15K.Set outlet static pressure to 0Pa.

Best regard

awuunity

ghorrocks April 26, 2012 18:39

This is all routine stuff, the normal boundaries can handle this. Your first post mentioned a finite slip wall - do you really need this?

awuunity April 27, 2012 22:06

3Q
 
Quote:

Originally Posted by ghorrocks (Post 357307)
This is all routine stuff, the normal boundaries can handle this. Your first post mentioned a finite slip wall - do you really need this?

Dear ghorrocks:

I learned the help documentation of cfx,I think that maybe i should choose to finite slip wall,but i dont know how to set slip speed according to my model.
Best regard

awuunity

ghorrocks April 29, 2012 06:50

Do you even know what a finite slip wall is?


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