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-   -   inflation layer, domain interface (http://www.cfd-online.com/Forums/cfx/126629-inflation-layer-domain-interface.html)

AKHILESH S L November 22, 2013 00:42

inflation layer, domain interface
 
hi friends,
while modelling a domain interface between fluid and solid, what is the way of giving inflation layer to the interface? is is essentially to give both the solid and fluid model? or is enough for giving the inflation to fluid layer only? which is the best way?

ghorrocks November 22, 2013 05:34

In a solid you only need a mesh fine enough to resolve the gradients. In steady state the gradients are very gentle so quite a coarse mesh is often good enough. In transient simulations the mesh size required will depend on the gradients created by the temperature changes over time.

But at the end of the day you should always do a mesh sensitivity check on these things and work out exactly what your simulation requires for the accuracy you desire.

AKHILESH S L November 22, 2013 11:26

thank you ghorrocks
for solids it is ok and i am doing a steady state analysis only. so for fluid layer inflation is necessary in solid-fluid interface right? i need to get the correct energy balance that's why i am in a confusion.

ghorrocks November 23, 2013 05:39

Energy balance is determined by how tight your convergence is. If you have an energy imbalance then just converge tighter. But to get the energy flow right you need an accurate simulation and that implies inflation layers, fine mesh and good emsh quality.

AKHILESH S L November 25, 2013 01:44

THANK YOU ghorrocks i need the correct energy balance. :) the problem is i am confused on the inflation layer on the solid-fluid interface. i need to finalize whether inflation is needed for solid or liquid layer? :(

ghorrocks November 25, 2013 02:12

For most simulations you need inflation on the fluid side but not on the solid side. But you should always check this for your case with a mesh sensitivity study.


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