Dear friends I create a 2d pipe model .my boundary condition is : Velocity inlet , pressure outlet , wall , and center line of pipe has Axis BC. When I export it to FLUENT. I received this message: A default (unspecified) continuum entity was created. Mesh successfully written to…. An another problem: I active Axismmetric bottom .(in solver panel ) Then I check my grid but FLUENT send warning for me: non-positive volumes exist or Invalid axisymmetric grid: 303 nodes lie below the x-axis. but when I inactive Aximmetric bottom I haven't any warning . Best regards Amir

Dear Amir,

The first error message is because you have not specfied anything in the boundary zones panel. Open the boundary zone panel and assign fluid zone to the volume that you have created. Regarding your second error message, I am not able to get you correctly. May be try remshing!

Good Luck Sun

The second error is because your part of your mesh lies below the x-axis. Check the FLUENT manual. For 2d axisymmetric cases, the axis of rotation must lie on the x-axis, and the entire mesh must lie ABOVE the x-axis. Easy way to fix this is to go to Grid->Translate, and then translate the grid so it lies above the x-axis. You don't have to go back to Gambit to define your continuum entity either. When FLUENT reads this mesh, it will assume your continuum is a fluid zone.

Goodluck, Jason

hi jason is saying right you have to translate it in positive xy plane