[Joke]

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

[rmatus]

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]

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]

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]

Thank you , Rick

[Black]

Originally Posted by Joke

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

Hi, Joke,

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