Fluid Solid Interface

npuh002 · August 26, 2014, 23:48

Hi Everyone.

I am running a FSI simulation on ANSYS 14 (I am new to FSI simulations in ANSYS).

The problem that I am currently trying to solve is attached. It is very similar to the "Oscillating Plate with Two-Way Fluid-Structure Interaction" tutorial. However in my problem the fluid is enclosed inside a cylindrical shell. A force is exerted onto the top of the gel and I am trying to figure how it behaves with the fluid (Water).

Currently it solves the structural side of things in the first iteration however when it tries to sync the structural output to FLUENT, it gives me the following error.

"System Coupling Exception
Origin : Fluid Flow (FLUENT) (Solution 2)
Error Code : 2
Error Description :
Fluent encountered fatal error after sync point Solve
"

Not too sure what this error means or how to get over it. Any help would be greatly appreciated.

I can upload my model if that would help.

Cheers,
Nikini

stumpy · August 27, 2014, 17:24

The error just means Fluent failed. You'd have to look at the Fluent log to find out why.

I would recommend going through the Fluent FSI training material which can be downloaded from the ANSYS customer portal. It has some best practice advice and should help you figure out the problem. You should look at the force and displacement values that are getting passed to see if they are reasonable.

npuh002 · September 1, 2014, 00:34

Hi Stumpy,

I have gone through the tutorials and set up my model to to the best of my ability. I am still stuck on this error.
I don't think it is the time stepping, ( I have reduced it and gives me the same error). I even applied the force in the middle of the simulation to check if it was due to passinf of the load from the gel, but it still gave the same error.
I have made sure that the Fluid Solid Interaction is set up in the structural side of things and also made the system coupling dynamic mesh in the fluent side of things. I also activated the appropriate remeshing and smoothing options in Fluent.

Really stumped with this one.

Cheers,
Nikini

newuser! · September 18, 2014, 02:35

Hi Nikini,

did you solved the problem?
I am going to model a quite similar system.... did you also tried to use CFX instead of Fluent?

Best regards
Philipp

npuh002 · September 27, 2014, 07:54

Hi,

Yeah I did solve this problem. Now moving onto realistic models... not going to be fun.
The main problem was that I was using and the automatic section called 'water-interior' as my internal deformable nodes. However this was not correct. i should have used the another one called just 'water'. I also had to change some of the remshing properties. But those are problem specific.

Cheers,
Nikini

September 18, 2014, 02:35	Problem solved?	#4
newuser! New Member Philipp Join Date: Jul 2014 Posts: 6 Rep Power: 11	Hi Nikini, did you solved the problem? I am going to model a quite similar system.... did you also tried to use CFX instead of Fluent? Best regards Philipp

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August 27, 2014, 17:24		#2
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	The error just means Fluent failed. You'd have to look at the Fluent log to find out why. I would recommend going through the Fluent FSI training material which can be downloaded from the ANSYS customer portal. It has some best practice advice and should help you figure out the problem. You should look at the force and displacement values that are getting passed to see if they are reasonable.

September 1, 2014, 00:34		#3
npuh002 New Member Nikini Gamage Join Date: Aug 2014 Posts: 7 Rep Power: 11	Hi Stumpy, I have gone through the tutorials and set up my model to to the best of my ability. I am still stuck on this error. I don't think it is the time stepping, ( I have reduced it and gives me the same error). I even applied the force in the middle of the simulation to check if it was due to passinf of the load from the gel, but it still gave the same error. I have made sure that the Fluid Solid Interaction is set up in the structural side of things and also made the system coupling dynamic mesh in the fluent side of things. I also activated the appropriate remeshing and smoothing options in Fluent. Really stumped with this one. Cheers, Nikini

September 27, 2014, 07:54		#5
npuh002 New Member Nikini Gamage Join Date: Aug 2014 Posts: 7 Rep Power: 11	Hi, Yeah I did solve this problem. Now moving onto realistic models... not going to be fun. The main problem was that I was using and the automatic section called 'water-interior' as my internal deformable nodes. However this was not correct. i should have used the another one called just 'water'. I also had to change some of the remshing properties. But those are problem specific. Cheers, Nikini