CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > REEF3D

Issue when using grid stretching

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 13, 2021, 09:37
Default Issue when using grid stretching
  #1
New Member
 
Joao Brazao
Join Date: Aug 2021
Posts: 7
Rep Power: 4
jfbrazao is on a distinguished road
Hi everyone, hope you're all well.

I've been optimising a model by changing the resolution of the grid in the area where I intend to place the solid of interest. Once I add grid stretching with option 8 - "three zones with constant d[...]" - the execution of Reef3D fails with the following message:
ERROR detected by Hypre ... BEGIN
ERROR -- hypre_BiCGSTABSolve: INFs and/or NaNs detected in input.
User probably placed non-numerics in supplied b.
Returning error flag += 101. Program not terminated.
ERROR detected by Hypre ... END
It runs without issues when I use a cubic cells size and a rectangular domain.

Does anyone have the same issue when running the input files?

Thank you in advance.

My system details for reference:

Model Name: MacBook Pro
Model Identifier: MacBookPro15,1
Processor Name: 6-Core Intel Core i7
Processor Speed: 2.6 GHz
Number of Processors: 1
Total Number of Cores: 6
Memory: 16 GB
Attached Images
File Type: jpg Screenshot 2021-09-13 at 14.34.28.jpg (61.8 KB, 22 views)
Attached Files
File Type: txt control.txt (156 Bytes, 12 views)
File Type: txt ctrl.txt (214 Bytes, 7 views)
jfbrazao is offline   Reply With Quote

Old   September 14, 2021, 02:45
Default
  #2
Senior Member
 
Arun Kamath
Join Date: Nov 2014
Location: Trondheim, Norway
Posts: 265
Rep Power: 13
kamath is on a distinguished road
Use B 2 to define the total number of cells. Otherwise the maximum number of cells is undefined and thus the decomposition incomplete.


Also you can use the output DIVEMesh-Non-Uniform-Mesh.txt to look at the max and min sizes and their locations.

Include B 130 1 and you get gridSpacing.vtk which shows you the grid in Paraview.
__________________
Arun
X years with REEF3D
kamath is offline   Reply With Quote

Old   September 15, 2021, 12:28
Default
  #3
New Member
 
Joao Brazao
Join Date: Aug 2021
Posts: 7
Rep Power: 4
jfbrazao is on a distinguished road
Quote:
Originally Posted by kamath View Post
Use B 2 to define the total number of cells. Otherwise the maximum number of cells is undefined and thus the decomposition incomplete.


Also you can use the output DIVEMesh-Non-Uniform-Mesh.txt to look at the max and min sizes and their locations.

Include B 130 1 and you get gridSpacing.vtk which shows you the grid in Paraview.
Hi Arun, thank you, that certainly helped test a bit more. The B130 is very handy for troubleshooting.

Edit: found the issue that was remaining in my interpretation of how the code in B 123 is used. The z1 and z2 are the absolute coordinate where to start the following section - I though they were additive to each other.

Thank you once again. Good stuff this.
jfbrazao is offline   Reply With Quote

Old   November 7, 2023, 07:43
Default
  #4
New Member
 
wangya
Join Date: Nov 2023
Posts: 1
Rep Power: 0
wangya is on a distinguished road
Quote:
Originally Posted by jfbrazao View Post
Hi Arun, thank you, that certainly helped test a bit more. The B130 is very handy for troubleshooting.

Edit: found the issue that was remaining in my interpretation of how the code in B 123 is used. The z1 and z2 are the absolute coordinate where to start the following section - I though they were additive to each other.

Thank you once again. Good stuff this.
Hi, jfbrazao, have you solved this problem? I recently encountered a similar issue while running a Fortran program but don't know where the bug is.
wangya is offline   Reply With Quote

Old   November 8, 2023, 13:45
Default
  #5
New Member
 
Joao Brazao
Join Date: Aug 2021
Posts: 7
Rep Power: 4
jfbrazao is on a distinguished road
Hi there wangya, I did solve the problem. The problem was misinterpretation of how to provide inputs to the variable grid sections. Testing it, by using B130, and then looking at the gridSpacing file on Paraview, was really helpful. I advise you do a couple tests, print with B130 and inspect your grid - you'll probably find what input you are providing that might be wrong. You just need to run the diveMESH, no need for a full simulation. Hope this helps!
jfbrazao is offline   Reply With Quote

Old   December 27, 2023, 08:02
Default
  #6
New Member
 
Keshav Pathak
Join Date: Jul 2022
Posts: 27
Rep Power: 3
keshav_20 is on a distinguished road
Hello REEF3D team
I am experiencing the same error while using spacing.dat file for generating the grid mesh.
My simulation runs ok while using the given options other than B 101 10, B 102 10 and B 103 10. However, I am getting the similar error while using the B 102 10 option.
I am attaching all the necessary files for your consideration.

Thank you

Regards
KP
Attached Files
File Type: txt control.txt (301 Bytes, 3 views)
File Type: txt ctrl.txt (354 Bytes, 2 views)
File Type: txt y-spacing.txt (328 Bytes, 8 views)
keshav_20 is offline   Reply With Quote

Old   January 14, 2024, 06:25
Default
  #7
Super Moderator
 
Hans Bihs
Join Date: Jun 2009
Location: Trondheim, Norway
Posts: 377
Rep Power: 17
valgrinda is on a distinguished road
Your y-spacing file contains "0.500" twice, so dy becomes zero there - resulting in divide by zero errors.
__________________
Hans Bihs
Team REEF3D
www.reef3d.com
valgrinda 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
Mapping results from CFD grid to structural grid of a free-form surface mbecker OpenFOAM Running, Solving & CFD 1 October 18, 2013 10:16
Grid stretching to achieve non-reflecting BCs lost.identity Main CFD Forum 4 December 1, 2009 14:35
Convergence issue with fine grid itisharisankar FLUENT 0 June 27, 2009 02:02
MapFields to New Grid For Extreme Grid Deformations due to Body Motion albcem OpenFOAM 0 May 5, 2009 14:17
Grid Quality and the Solution Faraz Main CFD Forum 4 January 10, 2000 18:18


All times are GMT -4. The time now is 23:38.