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club68512 February 27, 2010 06:12

thermal boundary option
 
hello everyone~
I have a problem about ...heat transfer coefficients that is from
model setup/boundaries/mesh boundaries/mesh block/wall/thermal information/thermal boundary options

there are heat transfer coefficient to fluid 1 &to fluid 2 ,does anybody know that means?
thanks

MuxaB February 28, 2010 20:52

if the mesh boundary is of type 'wall' with a specified temperature, then it needs an htc between the wall and adjacent fluid to compute the heat flux at the boundary. The user can defined a different htc for fluid 1 and 2 in two-fluid problems.

does it make sense?

ck5285 March 1, 2010 00:55

Michael
i thought the heat transfer coefficient is calculated by the solver while solving the conjugate heat transfer problem? pls help to clarify.

MuxaB March 1, 2010 12:23

Yes, the solver will do it if you leave these input entries blank.

club68512 March 3, 2010 11:07

Quote:

Originally Posted by MuxaB (Post 247831)
if the mesh boundary is of type 'wall' with a specified temperature, then it needs an htc between the wall and adjacent fluid to compute the heat flux at the boundary. The user can defined a different htc for fluid 1 and 2 in two-fluid problems.

does it make sense?

but if I set the 'wall' as copper that have thermal conductivity value(k),does it needs a htc ?

MuxaB March 3, 2010 19:27

It does not really matter what material it is made of. The user can either define a constant htc at the fluid/wall interface, or the code will compute it automatically as a function of the materials properties and the flow. In the latter case, it assumes that the contact between copper and fluid is perfect, i.e., no thermal resistance.


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