[BWLi]

Hi all,

First, Merry Christmas and Happy New Year!

I am recently trying to run a 2-way FSI with Ansys CFX and Transient Structural modules. It is a physiological case hence I set my initial pressure condition in CFX to 10666 Pa (80 mmHg equivalent). I verified the settings by running standalone CFX and Structural modules, respectively, and there is no problem.

However, during my coupling, my initial flow rate output from CFX is negative. I had never seen this situation before from CFD, and ideally the first step should not produce a large displacement transfer back to the fluid domain.

I am therefore wondering, how do CFX and Transient Structural initialise the solution at the first step.

A few things I have tried:
- 1-way FSI from CFX to Transient Structural only: no problem
- 2-way FSI but change the material property to ** structural steel **: no problem, but not physiologically true.
- lower my initial pressure: my initial flow rate is less negative, but does not really make a diff.