[hoyin]

Dear all,

I am trying to model a mechanical valve in a cylindrical pipe using 2-way FSI technique. Water is pumping from one end to the other end using pulse waveform. The valve is used to prevent back flow and is initially CLOSED. You can imagine the problem is to model a valve inside a blood vessel.

The problem I have now is that since the valve is closed at the beginning, the pipe is divided into 2 separate "fluid chambers" without "fluid" connection (i.e., the fluid before passing through and after passed through the valve). Here is what I did:

"I created named the surfaces on both sides of the valve. These 2 surfaces are used to couple the forces calculated from Fluent solver in System Coupling(SC). Therefore, I had 4 Data Transfers in SC: two Data Transfers (i.e., displacement and force) per each surface"

ANSYS returned error like Update-Dynamic-Mesh failed, Negative cell volume detected. I was thinking if it is becasue ANSYS may not know the 2 fluid chambers are connected if the valve is opened. May I ask expertise here for help?

I have tried if the valve is initially opened, the model works. In that model, I have one FSI interface only since both sides of the valve can consider as one surface. The meshing settings are similar in both case. So,I suspect the problem is due to separation 2 fluid chambers.


Thank you so much first !