Fluids

Fluids

How to fix distorted element mesh problem in ANSYS FSI simulutaion

Tagged: , ,

    • dxc200018
      Subscriber

       

      I'm attempting to do a 2 phase 2 way FSI fluid (air-water) and solid (human tissue) simulation on Ansys Fluent . There's force transfer and displacement transfer across 3 surfaces.

      My problem is that in the solid domain , I keep getting this error that says there is excessive distortion of elements. I wonder if the mesh isn't tracking the displacement correction. I'm using an unstructured mesh.

       

      I tried shrinking the mesh and using the "refine" option on surfaces with dispalcement, but eventually I shrunk the mesh so small the program told me it ran out of ram and wouldn't run.

      What are some meshing strategies to overcome this?

      Will changing the relexation factor in the system coupling module.

      I'm at my wit's end about what to do.

      Here's the error message I get.

      "

       +====================================================================+
       |                      System Coupling Exception                     |
       +====================================================================+
       | Origin            : Case6structural (Solution)                     |
       | Error Code        : 2                                              |
       | Error Description :                                                |
       |   Element 577059 (type = 3, SOLID187) (and maybe other elements)   |
       |   has become highly distorted.  Excessive distortion of elements   |
       |   is usually a symptom indicating the need for corrective action   |
       |   elsewhere.                                                       |
       +====================================================================+

      "

      "
      Error: Cortex received a fatal signal (SEGMENTATION VIOLATION).
      Error Object: ()
       52.7%
       57.5%"

    • Rahul Mule
      Ansys Employee

      Hi,

      This error may occur when unreasonable displacements were received by fluent or unreasonable forces were sent to Mechanical APDL. 

      Try with better mesh and increased number of substeps with loads applied at very small incremental value.

      It is very important to build up the FSI simulation in stages as opposed to setting up the 2-way FSI right at the start. This document "Best Practices for Coupled Fluid-Structure Interaction (FSI)" describes this process and is available here: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v221/en/sysc_ug/sysc_bestpractices_fsi.html

Viewing 1 reply thread
  • You must be logged in to reply to this topic.