Learning Forum

[Luca Capitelli]

Hello everyone, I'm a student and I'm trying to simulate the flow on a cylinder in 2d. I wanna find the drag coefficient for Re=500 and Re=50000 but the results are not satisfactory (Cd is about 0,37-0,38, too distant from target) so I try to define two different surfaces to develope two different meshes:

Now the setup can't solve the problem on the cylinder but only on the smaller rectangle, as it sees this one as a solid:

This is the result of the pressure. How can I solve the problem and find the Cd on the cylinder with the double mesh?

Thanks to everyone

[Rob]

Did you do share topology in geometry? In Fluent check the cell zone type, it needs to be "fluid" and then look for wall and wall:shadow pairs, in Boundary Conditions change that to interior. 

[Luca Capitelli]

thank you but I can't find "wall: shadow pairs". The cell zone type was fluid yet. Fluent call all the walls as "wall surface body" but I can't change them to interior.

[Rob]

Have you managed to create overlapping cell zones, but also managed to give them the same names? Please zoom in on the joint between the two zones and display the mesh.