Why surface_mesh does not have a quadratic option

[hrntsm]

Why is there a quadratic option for volume_mesh but not surface_mesh?
What if I want to create a quadratic element of a shell?

surface_mesh
https://prime.docs.pyansys.com/version/stable/api/_autosummary/ansys.meshing.prime.lucid.Mesh.surface_mesh.html

volume_mesh
https://prime.docs.pyansys.com/version/stable/api/_autosummary/ansys.meshing.prime.lucid.Mesh.volume_mesh.html

[waltersma]

Hi @hrntsm, in general this request does not come in very often. Is this something you need for a particular workflow you wish to create? If so then we should look at adding an issue as an enhancement request.

Thanks

[hrntsm]

Hi @waltersma,

We are currently creating a surface mesh as follows, followed by a volume mesh.

from ansys.meshing import prime
from ansys.meshing.prime import lucid
try:
    prime_client = prime.launch_prime()
    model = prime_client.model
    mesh_util = lucid.Mesh(model)
    cad_file_path = r'PATH.stp'
    mesh_util.read(cad_file_path)
    min = 5
    max = 7.5
    global_sizing_params = prime.GlobalSizingParams(
        model, min=min, max=max
    )
    model.set_global_sizing_params(global_sizing_params)
    mesh_util.surface_mesh()
    mesh_util.volume_mesh(quadratic=True)
    mesh_util.write(r'PATH.cdb')
finally:
    prime_client.exit()

For example, a curved surface such as a cylinder is meshed with a primary element, and then the volume mesh is meshed with a quadratic element.
This reduces the accuracy of shape reproduction, so we believe that a surface mesh of quadratic elements is necessary to create a volume mesh with a cleaner representation of the circle.

I am doing this because I could not create a volume mesh without meshing the surface mesh, is there another way?

[waltersma]

Hi @hrntsm,

If the objective is to create a volume mesh with quadratic elements where the mid side nodes are on the surface then there are a couple of different routes you could take to achieve this. My recommendation would be to project the mid side nodes to the geometry, however, please note this API is currently at beta and may change in future.

Example code:

import ansys.meshing.prime as prime

prime_client = prime.launch_prime()
model = prime_client.model
mesh_util = prime.lucid.Mesh(model=model)

mesh_util.read(file_name=prime.examples.download_block_model_fmd())

mesh_util.surface_mesh(min_size=5.0)
mesh_util.volume_mesh(quadratic=True)
params = prime.ProjectOnGeometryParams(model, project_only_mid_nodes=True, project_on_facets_if_cadnot_found=True)
prime.SurfaceUtilities(model).project_topo_faces_on_geometry(topo_faces=model.parts[0].get_topo_faces(), params=params)

I hope this helps!

[hrntsm]

@waltersma
Thank you for your help. Now I can create the mesh as I intended.
The problem has been solved.

This is a request, but since there is a quadratic option for volume, I think it would be natural to expect that surface also has that argument, so from a clarity perspective, I would appreciate it if you could consider this.