## 3D Design

#### ANSYS FLUENT – result in non manifold bodies

• aorta3
Subscriber

i've 3 bodies and make it as a new part. and i make a new enclosure. when i'm trying to do a boolean subtraction. i got this non manifold error. i'm totally new using ansys and hope someone help me to fix this error.

• Rob
Ansys Employee

It's a CAD issue and is typically triggered by two objects touching with zero overlap: which creates a surface with zero area or a volume that's zero thickness. Can you Unite the two curved bodies?

• aorta3
Subscriber

It's a CAD issue and is typically triggered by two objects touching with zero overlap: which creates a surface with zero area or a volume that's zero thickness. Can you Unite the two curved bodies?

when i'm unite the tho curved bodies i got this error.

• Rob
Ansys Employee

If they're surface bodies you may need to rethink how you build the model. What are you trying to do?

• aorta3
Subscriber
i must change it to 3D Solid Turbine ?
• Rob
Ansys Employee

Not necessarily, but you may need to split out a solid to avoid the problem.  If you intend the blades to spin you'll also need a rotating fluid zone. Have a look in the tutorials for examples of those.

• peteroznewman
Subscriber

I found it difficult in ANSYS 19.0 to subtract a surface from a solid.  Instead, I used the Thin operation to thicken the surface into a solid. I added a cylinder at the center and united that to the thickened blade. I created a large cylinder of air to enclose all the blades, then I sliced that into 120 degree slices. Finally, I was able to subtract the solid blade from the wedge of air.

Zoom into the hub at the center.  Note that on the cut faces the hub can be seen on both sides, making for a clean mesh on each slice.

If these three slices are united back into a cylinder, that is the rotating mesh domain.  An enclosure can be put outside this cylinder to represent the static domain for the air flowing toward this three blade turbine. ANSYS 19.0 archive attached.