[akshaydeshpande]

Hi all,
I am a beginner in ICEM CFD. I have meshed the Ahmed body in ICEM by following the tutorial on youtube and exported the mesh to Fluent. Even though there are no negative volumes in ICEM CFD (Fig 1), Fluent shows the error of presence of negative volumes. I have tried re-blocking and smoothing but the error persists. I have also attached a detailed picture of my mesh.
Please help!

[hwet]

i would suggest just use ansys meshing in workbench for this model rather than icem cfd

[akshaydeshpande]

Thanks for your reply! As far as i know, Ansys meshing gives an unstructured mesh. so will it be better than the structured mesh for calculations?

[hwet]

u can slice ur body into parts, simple geometry parts will have hex mesh then and complex may have tets (hybrid meshing), recently at a cfd conference an expert working with ansys explained that gone are the days when the solver did not give good results with tets, just remember to have inflation layer near the wall (10-15), having tets elsewhere is good enough.

[akshaydeshpande]

Thanks! I will try that. Meanwhile I am trying a 2d analysis of the same case but am getting problems while importing it to fluent. To rectify this:
1. I have checked for all associations along the perimeter curve by turning on the line elements and turning off the shells
2. I did an uncovered face check but no problem was found.
Even after following these steps, I am facing the same problem. I have attached images for reference. What else needs to be done?

[Far]

check this http://www.cfd-online.com/Forums/ans...h-quality.html