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FSI Modelling Capabilities?

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Hi all!

I am modelling a tube which acts as hyperelastic material. Inside the tube there is a fluid. Third object suppose to push this tube in one direction. Tubes edges are constrained. The problem is that when you leave no gap between pusher object and the tube, and form geometry as a union, you get a "glued" system - pusher is always bounded with a tube at the intersection point, and that way is no good. As i try forming geometry in an assembly mode other problems arise. Fluid-Structure interface boundary condition is no longer available and solver did not converge. So is there any way of simulating this kind of system?

Simulation performed without a pusher object and with a boundary load condition works, but it would be better if it would work with a pusher object.

Thank you

3 Replies Last Post 2016年9月15日 GMT-4 00:21
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Posted: 8 years ago 2016年9月12日 GMT-4 01:17
Does anyone encounter the same problem and have experience about it? If the "form assembly" is selected in last step in geometry setup, the fluid-solid interaction entity is not available, the fluid-solid boundary is not applicable if you choose them.
Does anyone encounter the same problem and have experience about it? If the "form assembly" is selected in last step in geometry setup, the fluid-solid interaction entity is not available, the fluid-solid boundary is not applicable if you choose them.

Nagi Elabbasi Facebook Reality Labs

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Posted: 8 years ago 2016年9月13日 GMT-4 13:26
Hi Zeng,

The fluid-structure boundary automatically detected by COMSOL requires a unioned geometry, I believe. COMSOL detects if you have a solid at one side and a fluid at the other side of the same surface (line in 2D), and creates the FSI boundary. If there is contact as in the case Edgaras described above you can add a Union operation before the final Assembly to connect the domains that make up the FSI boundary.

Nagi Elabbasi
Veryst Engineering
Hi Zeng, The fluid-structure boundary automatically detected by COMSOL requires a unioned geometry, I believe. COMSOL detects if you have a solid at one side and a fluid at the other side of the same surface (line in 2D), and creates the FSI boundary. If there is contact as in the case Edgaras described above you can add a Union operation before the final Assembly to connect the domains that make up the FSI boundary. Nagi Elabbasi Veryst Engineering

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Posted: 8 years ago 2016年9月15日 GMT-4 00:21
Dear Nagi,

Thanks a lot for your suggestion. I followed your advice and set up a simple model to implement it. stack three rectangular vertically. and suppose the intermediate rectangular denotes the fluid domain, and upper and lower two rectangular denotes solid domains. With "Union" before "form assembly", the upper fluid-solid interface is applicable to FSI tab, but for the lower fluid-solid interface, it's still not applicable to FSI. For this sample, can you give me some idea about it?

Thanks for your any comments.

Zeng
Dear Nagi, Thanks a lot for your suggestion. I followed your advice and set up a simple model to implement it. stack three rectangular vertically. and suppose the intermediate rectangular denotes the fluid domain, and upper and lower two rectangular denotes solid domains. With "Union" before "form assembly", the upper fluid-solid interface is applicable to FSI tab, but for the lower fluid-solid interface, it's still not applicable to FSI. For this sample, can you give me some idea about it? Thanks for your any comments. Zeng

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