Learning Forum

[mszoke]

Dear All,

I have been working on a two-way FSI simulation coupled between Fluent and Static Structural with unfortunately not too much luck.

The tutorials available on all platforms (here, youtube, etc.) focus on unsteady problem, but this one here is a steady state problem.

The problem is to simulate an airfoil inside a square duct of a wind tunnel and it looks as follows. We are interested in the deformation of the walls above and below the airfoil but only in its vicinity (i.e. not along the entire domain length, but only in its mid-portion). This portion of the wind tunnel comprises of tensioned Kevlar cloths.

A preliminary steady state simulation has been performed in fluent and it was loaded in Workbench. Here, I set the two walls above and below the airfoil to 'system coupling' and the fluid volume domain to 'deforming' under dynamic mesh.

The mechanical simulation contains two layers of walls separated from each other. BCs are fixed displacement along the edges of each body with FSI coupling on the surfaces facing the fluid domain.

The two solvers are coupled using System Coupling in Workbench. The two-way data transfers are set in this module.

Fluent throws the following error during the coupling step:

Invalid request method GetElementData for variable force

Unfortunately, I cannot find any source of information where this function (GetElementData) might be called from - it is not a valid UDF function for instance.

Could anyone please point me in the right direction? Any comments would be appreciated.

Thank you.

Matt

[Karthik Remella]

Hi,nIf I understand your question right, you are using fixed support on these surfaces and are coupling them with your Fluent model. The Fluent model will estimate the pressure load and apply this load on the top and bottom surfaces. Because of this, these surfaces will have to deform and you should allow this. This might be the issue. Please double-check your boundary conditions and make sure that you are setting up your fluid-solid interfaces correctly.nKarthikn

[mszoke]

Hi Kremella,nThank you for your comment!nI managed to get the simulation running last night. nThe only thing I did differently this time was that I started from a raw mesh and set the simulation settings and initialized it.Previously, I was loading the .cas.h5 and .dat.h5 files from a pre-set and pre-ran simulation. I am not sure if the new .h5 file save type in Fluent has anything to do with this error, but this was the only modification I did and now it works! nThank very much you for your time!nBest wishes,nMattnnn