Learning Forum

[audrey]

Hi,

I'm trying to simulate a water flow in a flexible tube (it is in latex). I take my parameters from the real system i made up. On this system, i observed that when there is a sufficient flow, the wall of the tube move, change the flow and finally, the tube collapse. I would like to simulate all of this on Ansys. It would be a two ways fluid structure interaction.

I choose to use the system coupling with Fluent and Mechanical. I make my geometry as it is showed on this tutorial : https://www.youtube.com/watch?v=DGPmyGFnzhA. So my interface fluid structure is a surface. Here is my parameters :

Structural properties :

density 1000 Kg.m^3 i've found that when i simulate it with the real density (340Kg.m^3) it hasn't been working

R = 1cm, L = 10cm, thickness = 2mm i've also founbd that it isn't working with the real thickness (0,2 mm)

Boundaries :

inlet : v = -0,3 m/s ; Pin = 10 Pa

Pout = 10 Pa

Initial values from the inlet

My structure has 15000 element and my fluid 25000 elements, my time step is 0,01 and start from 0 to 1 sec.

I can't have any of my simulation that let the structure deformation be more then 1,5 mm even if i increase slowly the velocity (with an udf). The purpose is to obtain something like this :

https://www.youtube.com/watch?v=Ug3mSETKoaA

When i run the simulation it tells me that the element has been to much distorded, i've tried to change the mesh and the time steps but not successfully.

My intuition tells me that it could be the fluid mesh that can't just decrased to much, so i've made research to know how dynamic mesh works. I use a remeshing and smoothing dynamic mesh but it still not works.

Did ou have any clue or idea about my problem?

Thank you.

 

[peteroznewman]

This member has been working on an elastomer tube that collapses.

Google search on his postings.

You might learn something useful by reading those discussions.