Learning Forum

[Emilie Westerling]

I have imported a stl file created by city4cfd with a geometry of a city into spaceclaim to save it as a sdoc file. I am trying to mesh the city side with the watertight workflow of fluent meshing. However, when I come to 'Generate surface mesh' part, fluent is asking: 'Boundary face zones (1) [] ?' and I have been trying several inputs, but honestly, I have no idea what fluent is asking. 

The last time I was trying to make it work I figured out that I should enter a name. However it ended the following:

 

Boundary face zones(1) [()] origin-mesh3.2-west

Boundary face zones(2) [()]

()

Boundary face zones(1) [()] origin-mesh3.2-west

Boundary face zones(2) [()] origin-mesh3.2-east

Boundary face zones(3) [()] origin-mesh3.2-north

Boundary face zones(4) [()] origin-mesh3.2-south

Boundary face zones(5) [()] origin-mesh3.2-top

Boundary face zones(6) [()]

()

Boundary face zones(1) [()] origin-mesh3.2-west

Boundary face zones(2) [()] origin-mesh3.2-east

Boundary face zones(3) [()] origin-mesh3.2-north

Boundary face zones(4) [()] origin-mesh3.2-south

Boundary face zones(5) [()] origin-mesh3.2-top

Boundary face zones(6) [()] origin-mesh3.2-water

Boundary face zones(7) [()] origin-mesh3.2-terrain

Boundary face zones(8) [()] origin-mesh3.2-vegetation

Boundary face zones(9) [()] origin-mesh3.2-buildings

Boundary face zones(10) [()]

()

Boundary face zones(1) [()] origin-mesh3.2-buildings

Boundary face zones(2) [()]

Deleted 0 faces with 3 free edges.

Deleted 0 faces with 2 free edges.

()

Boundary face zones(1) [()] origin-mesh3.2-vegetation

Boundary face zones(2) [()]

Deleted 39 faces with 3 free edges.

Deleted 15359 faces with 2 free edges.

Warning: Deleting empty objects (mesh3.2-water)

 

removed 19278 faces.

Warning: Deleting empty objects (mesh3.2-vegetation)

 

removed 127145 faces.

Warning: Deleting empty objects (mesh3.2-top)

 

removed 79 faces.

Warning: Deleting empty objects (mesh3.2-south)

 

removed 34 faces.

Warning: Deleting empty objects (mesh3.2-west)

 

removed 50 faces.

Warning: Deleting empty objects (mesh3.2-north)

 

removed 34 faces.

Warning: Deleting empty objects (mesh3.2-east)

 

removed 50 faces.

Warning: Deleting empty objects (mesh3.2-terrain)

 

removed 143885 faces.

1915 faces marked.

---- Warning--- Failed Share Topology in DM/SCDM, Attempting to repair model ....

 

Error: The model contains self-intersections which could not be automatically repaired

Error Object: #f

 

[Keyur Kanade]

If you have stl file then use fault tolerant meshing workflow. 

Please check : https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwibsumru5iDAxWCumMGHWPZDyYQwqsBegQICxAG&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DS9VGLXOIFZQ&usg=AOvVaw0hz2NdrDw2eQJ8Y3ap7S2Y&opi=89978449

 

Please go through help manual for more details 

Regards,

Keyur

How to access Ansys Online Help Document

Guidelines on the Student Community

Fluids Engineering Courses | Ansys Innovation Courses

 

[Emilie Westerling]

Thank you for directing me to the fault tolerant meshing workflow. However, I can not seem to generate a volume mesh since there are "Error: Empty face and/or edge zones.", my stl file describes a geometry of a part of a city consisting the water, vegetation, terrain, top and 4 sides surfaces (which form together a closed surface) and the buildings (which forms a closed surface without the other surfaces). A picture of the geometry is uploaded below (with two sides and the top hidden).

I defined the fluid region by the "Centeriod of objects" and I selected all objects for that. Am i doing something wrong in defining the fluid regions or other regions? Or is it not possible to mesh the geometry with this .stl file?

 

[Keyur Kanade]

Did you get the surface mesh? 

The error in volume meshing suggests that few zones are not captured well. So you may redefine fine sizes to capture different zones. 

Also please check extract edge zone option. 

Please go through help manual for more details 

Regards,

Keyur

How to access Ansys Online Help Document

Guidelines on the Student Community

Fluids Engineering Courses | Ansys Innovation Courses

 

[Emilie Westerling]

Yes I did get the surface mesh:

 

aAnd I used the extract edge feature "feature angle" and "sharp angle". However, I am now getting the following error, when trying to generate the volume mesh:

Error: CAR: invalid argument [1]: wrong type [not a pair]

Error Object: ()

---- Warning--- Zone name (water.1) does not exist in the final mesh.

---- Warning--- Zone name (vegetation.1) does not exist in the final mesh.

---- Warning--- Zone name (buildings.1) does not exist in the final mesh.

---- Warning--- Zone name (terrain.1) does not exist in the final mesh.

[Keyur Kanade]

You will need to work on sizing. 

Please check : https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v221/en/flu_ug/tgd_user_workflow_guided_tasks_setup_mesh_controls.html?q=curvature%20sizing

Regards,

Keyur

How to access Ansys Online Help Document

Guidelines on the Student Community

Fluids Engineering Courses | Ansys Innovation Courses