Predefined Cylinder Meshes

The dream.mesh module provides several helper functions to generate predefined meshes that are commonly used in aeroacoustic simulations around bluff bodies. Here, we showcase two of them:

• get_cylinder_mesh: an unstructured mesh around a cylinder, optionally with a fitted boundary layer, a graded transition region, and an outer sponge layer used to damp outgoing acoustic waves.

• get_cylinder_omesh: a structured O-grid (ring) mesh around a cylinder, with a fixed number of elements in the radial and polar directions.

import ngsolve as ngs
from ngsolve.webgui import Draw
from dream.mesh import get_cylinder_mesh, get_cylinder_omesh

Unstructured mesh with a sponge layer

We generate a mesh with radius \(0.5\) and an outer sponge layer used to damp outgoing waves, and inspect the resulting domains and boundaries.

mesh = get_cylinder_mesh(radius=0.5, sponge_layer=True, curve_layers=True)

print("Materials:", mesh.GetMaterials())
print("Boundaries:", mesh.GetBoundaries())

mesh.Curve(3)
Draw(mesh)

Materials: ('sponge', 'sound', 'sound', 'sound', 'sound', 'sound', 'sound', 'sound')
Boundaries: ('inflow', 'outflow', 'default', 'default', 'default', 'default', 'default', 'default', 'default', 'default', 'default', 'default', 'default', 'cylinder')

WebGLScene

Structured O-grid mesh

Alternatively, get_cylinder_omesh generates a fully structured ring mesh, here with \(32\) elements in the polar direction and \(8\) in the radial direction.

omesh = get_cylinder_omesh(ri=0.5, ro=5.0, n_polar=32, n_radial=8)

print("Materials:", omesh.GetMaterials())
print("Boundaries:", omesh.GetBoundaries())

Draw(omesh)

Materials: ('default',)
Boundaries: ('cylinder', 'left', 'right')

WebGLScene