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

Negative nut occurring intermittently

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 2, 2021, 16:46
Default Negative nut occurring intermittently
  #1
Member
 
Adithya
Join Date: May 2021
Posts: 73
Rep Power: 4
Adithya_11 is on a distinguished road
Hello
I am simulating an aircraft with the SA model.
Turbulent settings as per recommendations by Spalart and Rumsey. Coupled scheme with time factor 0.1 . All second order spatial discretization.

In my mesh, i know that i have a few (<300 cells in a total of 85million) highly skewed elements.
I also have very low orthogonality in some cells at different location.

In the first 5 or so iterations, i get a warning message that a negative nut was calculated. It then disappears till around iteration 700. After that it reappears intermittently with a warning in around 1 to 7 cells.

My x,y,z,energy, and nut residuals decrease steadily. My continuity however oscillates but also decreasing.

Is this occurrence at a higher number of iteration something to be worried about? Can the solution diverge at this stage?
If so, how do i correct it?
Adithya_11 is offline   Reply With Quote

Reply


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
[Other] mesh airfoil NACA0012 anand_30 OpenFOAM Meshing & Mesh Conversion 13 March 7, 2022 17:22
[blockMesh] non-orthogonal faces and incorrect orientation? nennbs OpenFOAM Meshing & Mesh Conversion 7 April 17, 2013 05:42
[blockMesh] error message with modeling a cube with a hold at the center hsingtzu OpenFOAM Meshing & Mesh Conversion 2 March 14, 2012 09:56
[blockMesh] BlockMesh FOAM warning gaottino OpenFOAM Meshing & Mesh Conversion 7 July 19, 2010 14:11
[blockMesh] Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Meshing & Mesh Conversion 10 April 2, 2007 14:00


All times are GMT -4. The time now is 15:21.