Hi there,

I am using fluent to model a 2D airfoil flow, the mesh was generated using Gambit with a boundary layer.

I am getting a warning message when using grid check in fluent:

WARNING: non-positive volumes exist.

minimum volume(m3): -3.565426e-12 maximum volume(m3): 1.663969e-01 total volume (m3): 3.139505+02

Face area statistics: minimum face area (m2): 8.642673e-07 maximum face area (m2): 6.597350e-01

Why am I getting non-positive volume while the minimum face area is greater than zero?

Could anybody give me a clue?

Thanks Wenbin

Sometimes this happens with gambit. The solution is to use the examine mesh tool in gambit to identify the problem areas and re-mesh them. The most common situation for me when this comes up is when there is a very narrow space between two volumes. Sometimes you can fix it using an alternate meshing algorithm, and sometimes you have to find a different way to subdivide the domain.

this is usually happen when two mesh lines are intersecting each other

check themesh quality and see the areas which are narrow and mesh quality is bad , u will oberseve the above said thing

regards