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-   -   Problem found in Pointwise - Fluent (http://www.cfd-online.com/Forums/pointwise/92016-problem-found-pointwise-fluent.html)

Joke August 30, 2011 08:10

Problem found in Pointwise - Fluent
 
Hi, everyone
thank you for your kindly support me.

I created 2Dmesh of backward stepping flow problem in pointwise and exported as .case file to run simulation in fluent.
When I checked mesh in fluent, it told that "non-positive volume exist".
I applied the inlet velocity at boundary on the left hand side with type "Magnitude,Normal to boundary" say 1m/s and I performed initialization, the result show that my velocity is -1m/s. The simulation still run and the result showed that fluid is flow from right to left ! (Infact it should flow from left to right)

http://imageshack.us/photo/my-images...isefluent.png/

Could anyone guide me "What cause theis problems ? (Pointwise or fluent) and how to solve it"

thank in advance

joke

http://imageshack.us/photo/my-images...isefluent.png/

rmatus August 30, 2011 09:26

Check your grid normals in Pointwise
 
Hi John:

In Pointwise, check the grid and make sure it is right-handed. (Use Edit, Orient to check the I, J directions and change them if necessary to make the grid right-handed.) This is the most likely cause of negative volume cells in a 2D mesh.

Hope this helps,
Rick

Joke August 30, 2011 10:41

Hi, rmatus
thank you very much rmatus. It's very helpful.

May I confirm your answers, If I want to make a grid right-hand : I should point to the right, J point upward and K should point outward from the computer, right?

rmatus August 30, 2011 11:15

Right-handed
 
Joke:

That's right. I to the right, J up, which means K is coming out of the screen. That will be right-handed.

Rick

Joke August 30, 2011 20:46

Thank you , Rick

Black September 22, 2013 06:23

Quote:

Originally Posted by Joke (Post 322262)
Hi, everyone
thank you for your kindly support me.

I created 2Dmesh of backward stepping flow problem in pointwise and exported as .case file to run simulation in fluent.
When I checked mesh in fluent, it told that "non-positive volume exist".
I applied the inlet velocity at boundary on the left hand side with type "Magnitude,Normal to boundary" say 1m/s and I performed initialization, the result show that my velocity is -1m/s. The simulation still run and the result showed that fluid is flow from right to left ! (Infact it should flow from left to right)

http://imageshack.us/photo/my-images...isefluent.png/

Could anyone guide me "What cause theis problems ? (Pointwise or fluent) and how to solve it"

thank in advance

joke

http://imageshack.us/photo/my-images...isefluent.png/

Hi, Joke,

Or you can try the command 'mesh/repair-improve/repair' in Fluent command line.
May help to you.


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