[zjuv9021]

Hi all,

I am trying to understand the impact of the fluid region within the lumen of a catheter as it is bent and buckles. Understanding that the cross sectional area within the fluid region will be altered as buckling occurs.

The catheter and fluid region start out as a straight simple tube, but then is bent via Mechanical DX as a Rigid Joint rotation by 30 degrees about the x-axis (Capture Image).

The inlet of the fluid region is to the far left (- y direction), and the outlet is at the end of the rigid body joint that is rotating as is marked in the attached picture.

I've set up my System Coupling in Workbench, but am running into negative volume difficulties, and it appears as though my Outlet BC mesh is not moving, as I set it in CFX-pre to "Unspecified", as I did not know how to properly choose.

My inlet will be "Stationary", as there wont be any movement far away from the deformation, and my Walls within the lumen are indeed set to "System Coupling" to read in the deformation from structural.

My question: HOW exactly do I define my Outlet face in conjunction with my transient structural 30 degree rotation of the catheter tubing so that I am in sync? I am assuming that this is where the problem lies.

Kind Regards,
Zach

[ghorrocks]

Can you describe what you are doing and label your image better? What is the fluid domain? What are you trying to get out of this analysis - the flow resistance of the catheter when it is bent? Or something else? Where are the negative volume elements reported on your geometry?