Meshing a Mixing Elbow for a Flow Analysis

Summary: This example illustrates how to mesh a mixing elbow for a flow analysis.

Objective

In this example, you can mesh a mixing elbow with polyhedral elements and wall boundary layer refinement. you use several meshing utilities available in the lucid class for convenience and ease.

Procedure

• Launch Ansys Prime Server and instantiate meshing utilities from lucid class

• Import geometry and create face zones from labels imported from geometry.

• Surface mesh geometry with curvature sizing.

• Volume mesh with polyhedral elements and boundary layer refinement.

• Print statistics on generated mesh.

• Write a cas file for use in the Fluent solver.

• Exit the PyPrimeMesh session.

Launch Ansys Prime Server

. Import all necessary modules.

# . Launch an instance of Ansys Prime Server.

# . Connect PyPrimeMesh client and get the model.

# . Instantiate meshing utilities from Lucid class.

import os
import tempfile

from ansys.meshing import prime
from ansys.meshing.prime.graphics import Graphics

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

Import Geometry

. Download the elbow geometry file (.fmd file exported by SpaceClaim).

# . Import geometry.

# . Create face zones from labels imported from geometry for use in Fluent solver.

mixing_elbow = prime.examples.download_elbow_fmd()
mesh_util.read(file_name=mixing_elbow)
mesh_util.create_zones_from_labels("inlet,outlet")

Surface Mesh

. Surface mesh the geometry setting min and max sizing that will be used for curvature refinement.

mesh_util.surface_mesh(min_size=5, max_size=20)

Volume Mesh

. Volume mesh with polyhedral elements and boundary layer refinement.

# . Fill the volume with polyhedral and prism mesh
# specifying location and number of layers for prisms.

# Expressions are used to define the surfaces to have prisms grown
# where "* !inlet !outlet" states "all not inlet or outlet".

mesh_util.volume_mesh(
    volume_fill_type=prime.VolumeFillType.POLY,
    prism_surface_expression="* !inlet !outlet",
    prism_layers=3,
)

# Display the mesh
display = Graphics(model=model)
display()

Print Mesh Statistics

# Get meshed part
part = model.get_part_by_name("flow_volume")

# Get statistics on the mesh
part_summary_res = part.get_summary(prime.PartSummaryParams(model=model))

# Get element quality on all parts in the model
search = prime.VolumeSearch(model=model)
params = prime.VolumeQualitySummaryParams(
    model=model,
    scope=prime.ScopeDefinition(model=model, part_expression="*"),
    cell_quality_measures=[prime.CellQualityMeasure.SKEWNESS],
    quality_limit=[0.95],
)
results = search.get_volume_quality_summary(params=params)

# Print statistics on meshed part
print(part_summary_res)
print("\nMaximum skewness: ", results.quality_results_part[0].max_quality)

message :
Part Name: flow_volume
Part ID: 2
    13 Topo Edges
    9 Topo Faces
    1 Topo Volumes

    0 Edge Zones
        Edge Zone Name(s) : []
    2 Face Zones
        Face Zone Name(s) : [inlet, outlet]
    1 Volume Zones
        Volume Zone Name(s) : [volume]

    2 Label(s)
        Names: [inlet, outlet]

    Bounding box (-203.2 -228.6 -50.8)
                 (203.2 203.2 50.8)

    Mesh Summary:
        22552 Nodes
        1970 Poly Faces
        0 Quad Faces
        0 Tri Faces
        1970 Faces
        7595 Poly Cells
        0 Hex Cells
        0 Prism Cells
        0 Pyramid Cells
        0 Tet Cells
        7595 Cells
    0 out of 9 TopoFaces are unmeshed

n_topo_edges :  13
n_topo_faces :  9
n_topo_volumes :  1
n_edge_zonelets :  0
n_face_zonelets :  0
n_cell_zonelets :  0
n_edge_zones :  0
n_face_zones :  2
n_volume_zones :  1
n_labels :  2
n_nodes :  22552
n_faces :  1970
n_cells :  7595
n_tri_faces :  0
n_poly_faces :  1970
n_quad_faces :  0
n_tet_cells :  0
n_pyra_cells :  0
n_prism_cells :  0
n_poly_cells :  7595
n_hex_cells :  0
n_unmeshed_topo_faces :  0

Maximum skewness:  0.798258

Write Mesh

Write a cas file for use in the Fluent solver.

with tempfile.TemporaryDirectory() as temp_folder:
    mesh_file = os.path.join(temp_folder, "mixing_elbow.cas")
    mesh_util.write(mesh_file)
    assert os.path.exists(mesh_file)
    print("\nExported file:\n", mesh_file)

Exported file:
 /tmp/tmpp868670q/mixing_elbow.cas

Exit PyPrimeMesh

prime_client.exit()