CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Dynamic meshing cell stretch

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 7, 2022, 04:23
Arrow Dynamic meshing cell stretch
  #1
New Member
 
Join Date: Mar 2021
Posts: 18
Rep Power: 5
jojoFD is on a distinguished road
Hi,

I simulate an object oscillating in water (multiphase flow, VOF). My mesh needs to be dynamic to follow the motion and therefore I am using triangular cells (refined locally down to 0.1m size) and a remeshing method with rigid body motion.

I defined a sphere encapsulating my object and I move this sphere using a UDF CG MOTION following a sinus curve up to 1.95m/s with a period of 10s, to oscillate at the water interface. The BC are defined as all walls, and the water is still (no waves).

The problem I get is that the cells at the edge of my sphere are stretching too much and cause a negative cell volume error, even when I decrease the timestep down to 0.01s. And I can't reduce it more for computation time reasons.

I recently tried the implicit update option, but it failed as well a couple of seconds later than the simulation without the option.

As the remeshing method concerns the whole domain, these stretched cells are too big compared to the surrounding ones, but still smaller than the ones far from the object: so Fluent doesn't get that it should remesh it. I tried constraining the cell, face skewness and using every other option available in the remeshing method but without success.

Does anyone have an idea on how to solve this, please?

Thanks a lot in advance for your help !

Inked2022-04-04_14h54_42_LI.jpg
Attachment 89210
hull in water.PNG
jojoFD is offline   Reply With Quote

Reply

Tags
dynamic mesh, negative cell volume, remeshing

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[ANSYS Meshing] Is it possible to generate mesh in different cell zones in Ansys meshing? aja1345 ANSYS Meshing & Geometry 0 October 3, 2018 14:22
Dynamic Meshing of Simple 2D Geometry harman79 FLUENT 2 January 17, 2018 06:07
simple 2d open ended cylinder with moving piston: dynamic meshing query lmarf88 ANSYS 0 January 6, 2014 09:55
Dynamic Mesh.. Layering.. cell addition kedarj14 OpenFOAM Programming & Development 0 January 29, 2010 01:48
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Meshing & Mesh Conversion 2 July 15, 2005 04:15


All times are GMT -4. The time now is 05:02.