two phase channel flow
 

Hi every one.
I have 3D open channel. Would any one please tell me in using interfoam, Do we have to define two blocks in the surface? one for water and one for atmosphere?
I it is so, dose it matter to have only one layer of cells for air?
Thanks a lot.

its not necessary to defines two two blocks :).
you can use groovyBC to define a variable inlet for different phases.

Some questions about your post
 

Dear Dr. Samkhaniani,
Thanks a lot for your valuable post. I have your book and saw the chapter for interfoam. in page 169 of the second edition of your book I found the boundary condition you told me. but I do not understand some parts of it:
1- can I use variableHeightFlowRateInletVelocity instead?
2- if so, in page 169, you have defined velocity as value uniform (0 0 0), why?
3- would you please explain the lines of BC groovy in this page? I mean:
valueExpression "vector...."
4- On the surface of the channel, is it enough to define pressureInletOutletVelocity?
5- I want to enter a fully developed flow in the inlet. If it is so, is it necessary to define extra block for air?
I am really sorry for bothering you so much.
But unfortunately I have a lot of unanswered questions about openfoam.:confused:
Thanks a lot and best regards.

Dear Dr. Samkhaniani,
I thought, may be it is useful to send you my bockmesh file. I want to enter a fully developed flow in the inlet and outlet. Would you please please please help me to define boundary conditions in u, p and alfa files? thanks a lot.

Dear fatemeh
1- yep , you can use variableHeightFlowRateInletVelocity, however i should emphasize that this boundary is affected by down stream flow.

2-value is place holder, the value of groovyBC is defined using valueExpression

3-see book appendix

4- yep, for p you can use totalPressure and for U use pressureInletOutletVelocity

5-nope it is not necessary to define two blocks, for inlet you can define velocity profile using groovyBC, i recommend you to read book appendix and see following web page:
https://openfoamwiki.net/index.php/Contrib/groovyBC

Dear Dr. Samkhaniani,
Thanks a lot for helping me so much but unfortunately, I didn't see any appendix.
Would you please send it to my email:
f.farshi@cv.iut.ac.ir
Thanks a lot and best regards.