CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Minimum Size Constraints on Simulations Query

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

LinkBack Thread Tools Display Modes
Old   November 28, 2016, 14:29
Question Minimum Size Constraints on Simulations Query
New Member
Craig Leddicoat
Join Date: Nov 2016
Posts: 2
Rep Power: 0
Leddsworth is on a distinguished road
Ahoy hoy,

Been running into bother meshing and running Fluent simulations involving exceptionally small geometry dimensions, around 1mm to 5mm wide fluid passages, and was wondering if there is some lower limit on the size Ansys can reasonably simulate?

From my analysis of the problem messages after trying a wealth of meshing methods, the automation seems to struggle with surfaces of the pipe walls and fluid boundaries and is creating interfacing at these dimensions that shouldn't be there. I have tried a few work around's already, including manually setting all the contact regions but I am still plagued by failing meshes, conflicting zone names and unresolvable contact regions.
The image shows a sample of the heat exchanger concept, outer Fluid region, Central Pipe Wall Region and Inner Fluid Region.

Can anyone please advise a method to successfully mesh and discretize this model?
Leddsworth is offline   Reply With Quote

Old   November 28, 2016, 16:08
Senior Member
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,932
Rep Power: 26
LuckyTran will become famous soon enoughLuckyTran will become famous soon enough
There is a lower limit because Fluent works natively in meters, but it's around 1e-06 m. Fluent shouldn't have issues with mm scale features.
LuckyTran is offline   Reply With Quote

Old   December 1, 2016, 06:02
New Member
Craig Leddicoat
Join Date: Nov 2016
Posts: 2
Rep Power: 0
Leddsworth is on a distinguished road
You are correct, Ansys is capable of computing simulations at dimensions this small.

The errors seemed to stem from automated face pairing for connections on a series of layer 3D curved faces. I managed to resolve the conflict by better defining the contacting parts by grouping parts together in the Geometry editor to minimise the number of contact regions in the Mesh editor.
Leddsworth is offline   Reply With Quote


fluent, heat and mass transfer, heat exchanger two fluids

Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Reduce size of Ansys.rst file in FSI simulations? Jorn CFX 6 September 21, 2017 03:00
courant number in vof reza_gharib1369 FLUENT 8 August 25, 2016 04:52
Minimum possible element size Tscar Main CFD Forum 3 February 12, 2016 14:50
Minimum mesh size for Advection-Diffusion Problem Murf CFX 4 March 5, 2015 15:15
minimum mesh size for CFX julien CFX 1 January 12, 2006 07:37

All times are GMT -4. The time now is 05:20.