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-   -   Problem with meshing (https://www.cfd-online.com/Forums/flow-3d/137931-problem-meshing.html)

mina00 June 25, 2014 12:45

Problem with meshing
 
Hello

I have a problem with meshing in Flow3D.
When I put the total cells 40000, FAVOR isn’t good and when I put the total cells more than 40000, a solid part add to geometry file!!!! Related pictures are attached.
I don’t know reason of it??

Can everyone help me??

So thanks.

http://www.uploadax.com/images/54013823563731198449.jpg
http://www.uploadax.com/images/37546274300886245809.jpg

pankajl July 4, 2014 08:35

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.

mina00 July 4, 2014 12:04

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?

pankajl July 7, 2014 00:47

Can you send me prepin and required stls. I will see if I can get it working for you

mina00 July 8, 2014 11:00

Hello pankajl.
It is my prepin file.
So thanks.

http://upir.ir/934/weir.zip

pankajl July 9, 2014 07:31

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 July 11, 2014 08:10

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??

pankajl July 11, 2014 08:23

Yes, Definitely !

total no of cells for block 1 = 1,00,000 and For block 2 = 2,00,000

mina00 July 11, 2014 08:38

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??

pankajl July 11, 2014 08:48

1 Attachment(s)
Please find attached prepin. This is working fine, also copy attached .flow3dproj in your simulation folder

mina00 July 11, 2014 09:11

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?

Milad h July 12, 2014 07:31

hi
for your mesh problem you must change your Runtime option

mina00 July 12, 2014 08:14

Hello
Can you explain more?? why Runtime option??

Milad h July 12, 2014 10:52

you must change your timestep from below way
Runtime option > min timestep
you must reduce your timestep

AHMED HELMI July 18, 2017 08:16

pipe meshing problem
 
hi can any one support me in meshing a two different diameter pipes flowing into a manhole with different discharges


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