2-Way FSI Highly Distorted Elm Error

  • Last Post 15 May 2018
  • Topic Is Solved
learn13 posted this 19 March 2018

Trying to simulate a simple 2-way FSI: fluid flow over a beam with a low modulus (1e4 Pa) based on the oscillating plate tutorial geometry.  Changing the mesh and transient properties has helped to a degree but the highly distorted element error persists.  The error reports that the structural component is at fault, but the animation (attached) shows Fluent's mesh distorting.  It is likely not showing the structural distortion.

Any help would be appreciated.  Attached are the workbench files, animation, and photo demonstrating the distortion.

Mesh and time steps were reduced for file size.

Attached Files

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learn13 posted this 19 March 2018

Currently unable to attach workbench files.

learn13 posted this 20 March 2018

I've been able to resolve the issues with the model above with better mesh definitions and better understanding of coupled time stepping.

This problem seems more resilient when reducing everything to the micrometer scale length.  The first iteration fails every time, even with end time as 1e-15 and stepping time 1e-17.  The initial 'impact' of the pressure wave and the resultant shear force is causing distorted elements.

learn13 posted this 15 May 2018

Resolved by shifting the analysis from 2D to 3D.

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