CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLOW-3D

Problem with meshing

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

Like Tree5Likes
  • 1 Post By pankajl
  • 1 Post By pankajl
  • 1 Post By pankajl
  • 1 Post By Milad h
  • 1 Post By Milad h

Reply
 
LinkBack Thread Tools Display Modes
Old   June 25, 2014, 12:45
Exclamation Problem with meshing
  #1
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Hello

I have a problem with meshing in Flow3D.
When I put the total cells 40000, FAVOR isnít good and when I put the total cells more than 40000, a solid part add to geometry file!!!! Related pictures are attached.
I donít know reason of it??

Can everyone help me??

So thanks.

http://www.uploadax.com/images/54013823563731198449.jpg
http://www.uploadax.com/images/37546274300886245809.jpg
mina00 is offline   Reply With Quote

Old   July 4, 2014, 08:35
Default
  #2
New Member
 
Pankaj Lawande
Join Date: Mar 2014
Posts: 7
Rep Power: 3
pankajl is on a distinguished road
I have couple of questions

1. What is the size of solid part which is getting added?

2. Is this part present in original geometry ?

if not then your part is getting visualized correctly when you have refined mesh.
pankajl is offline   Reply With Quote

Old   July 4, 2014, 12:04
Default
  #3
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Hello pankajl.
This part isn't present in my original geometry.
I refined the mesh. but when solver run, this error appear:
Solver Messages:
convective flux exceeded stability limit
at t= 1.2892E-02 cycle= 1 iter= 45 delt= 1.2892E-02 mesh block 1
restarting cycle with smaller time step
maximum failure ratio = 1.26154E+01 is in x-coordinate direction
at cell ( 78, 10, 10) mesh block 1


My geometry is very simple and i Don't think to need the mesh more finder.
Can you guide me?
mina00 is offline   Reply With Quote

Old   July 7, 2014, 00:47
Default
  #4
New Member
 
Pankaj Lawande
Join Date: Mar 2014
Posts: 7
Rep Power: 3
pankajl is on a distinguished road
Can you send me prepin and required stls. I will see if I can get it working for you
pankajl is offline   Reply With Quote

Old   July 8, 2014, 11:00
Default
  #5
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Hello pankajl.
It is my prepin file.
So thanks.

http://upir.ir/934/weir.zip
mina00 is offline   Reply With Quote

Old   July 9, 2014, 07:31
Default
  #6
New Member
 
Pankaj Lawande
Join Date: Mar 2014
Posts: 7
Rep Power: 3
pankajl is on a distinguished road
You can adjust you mesh blocks to have good aspect ratio,Try block 1 with 0.1M cells and block 2 0.2M cells.This should fix your problem.
Initially you will see solver taking smaller time steps but nothing to worry about this.
mina00 likes this.
pankajl is offline   Reply With Quote

Old   July 11, 2014, 08:10
Default
  #7
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Your order of 0.1M and 0.2M is size of mesh??
I'm mew in Flow3D and i have many problem about it.
So thanks for your guide.
I examine your suggest, but if i have other problem, can i ask you??
mina00 is offline   Reply With Quote

Old   July 11, 2014, 08:23
Default
  #8
New Member
 
Pankaj Lawande
Join Date: Mar 2014
Posts: 7
Rep Power: 3
pankajl is on a distinguished road
Yes, Definitely !

total no of cells for block 1 = 1,00,000 and For block 2 = 2,00,000
mina00 likes this.
pankajl is offline   Reply With Quote

Old   July 11, 2014, 08:38
Default
  #9
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Thanks alot.
now, the program is running but the same error appear initially.
It is not important?
How you determine the total number of cells??
if dimension of my model is bigger, how can i determine total number of cells??
mina00 is offline   Reply With Quote

Old   July 11, 2014, 08:48
Default
  #10
New Member
 
Pankaj Lawande
Join Date: Mar 2014
Posts: 7
Rep Power: 3
pankajl is on a distinguished road
Please find attached prepin. This is working fine, also copy attached .flow3dproj in your simulation folder
Attached Files
File Type: zip weir_v11.zip (2.9 KB, 9 views)
mina00 likes this.
pankajl is offline   Reply With Quote

Old   July 11, 2014, 09:11
Default
  #11
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
while program is running, in initial solver error is appear. is it warning and isn't error??
Program is running 2% now. Is this error appear for you, if you running?
mina00 is offline   Reply With Quote

Old   July 12, 2014, 07:31
Default
  #12
New Member
 
mh
Join Date: Jul 2014
Posts: 5
Rep Power: 3
Milad h is on a distinguished road
hi
for your mesh problem you must change your Runtime option
mina00 likes this.
Milad h is offline   Reply With Quote

Old   July 12, 2014, 08:14
Default
  #13
Member
 
mina salehi
Join Date: Jan 2014
Posts: 30
Rep Power: 3
mina00 is on a distinguished road
Hello
Can you explain more?? why Runtime option??
mina00 is offline   Reply With Quote

Old   July 12, 2014, 10:52
Default
  #14
New Member
 
mh
Join Date: Jul 2014
Posts: 5
Rep Power: 3
Milad h is on a distinguished road
you must change your timestep from below way
Runtime option > min timestep
you must reduce your timestep
mina00 likes this.
Milad h is offline   Reply With Quote

Reply

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
Problem with querying the meshing database in CFX-Pre ashtonJ CFX 6 Today 02:12
[Other] Hex meshing problem DM12 patrick ANSYS Meshing & Geometry 7 January 9, 2015 08:21
[ANSYS Meshing] Inflation - Airfoil Meshing - Divergence problem dalecooper ANSYS Meshing & Geometry 0 July 19, 2013 07:04
Meshing problem in GAMBIT Vidya Raja FLUENT 0 May 20, 2006 23:31
GAMBIT meshing problem Gauthier Lambert Main CFD Forum 1 August 3, 2000 09:22


All times are GMT -4. The time now is 06:12.