Dear Seifollah,

I can try to answer your question.

In for instance ADINA-FSI you can use a pressure boundary condition on the CFD part. Use the normal traction boundary condition.

*

TIMEFUNCTION NAME=1

CLEAR

0 0

100 0

*

LOAD NORMAL-TRACTION NAME=1 MAGNITUD=1.0

*

APPLY-LOAD BODY=1

1 'NORMAL-TRACTION' 1 'FACE' 1 0 1

*

See chapter 3.4.2 Usual boundary conditions for fluid in the Theory and Modeling Guide Volume III: CFD & FSI.

I hope I understood your question and that you find it helpful.

Best regards, Kenth

Dear Kenth

Thank you very much for your response

Yes, it can be used.

I have seen in some articles that zero pressure has been used as an outlet boundary condition in FSI problems solving by Comsol.