def background_mesh(res=0.025):
"""
Create rectangular background mesh for the Poisson problem
"""
geometry = Geometry()
rectangle = geometry.add_rectangle(0, L, 0, H, 0, res)
geometry.add_physical_surface(rectangle.surface, label=12)
geometry.add_physical_line(rectangle.line_loop.lines, label=outer_marker)
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry, prune_z_0=True)
meshio.write(
"meshes/multimesh_0.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf_0.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
def single_mesh(res=0.025):
geometry = Geometry()
c = geometry.add_point((c_x, c_y, 0))
# Elliptic obstacle
p1 = geometry.add_point((c_x - r_x, c_y, 0))
p2 = geometry.add_point((c_x, c_y + r_y, 0))
p3 = geometry.add_point((c_x + r_x, c_y, 0))
p4 = geometry.add_point((c_x, c_y - r_y, 0))
arc_1 = geometry.add_ellipse_arc(p1, c, p2, p2)
arc_2 = geometry.add_ellipse_arc(p2, c, p3, p3)
arc_3 = geometry.add_ellipse_arc(p3, c, p4, p4)
arc_4 = geometry.add_ellipse_arc(p4, c, p1, p1)
obstacle_loop = geometry.add_line_loop([arc_1, arc_2, arc_3, arc_4])
obstacle = geometry.add_surface(obstacle_loop)
rectangle = geometry.add_rectangle(0,
L,
0,
H,
0,
res,
holes=[obstacle_loop])
# geometry.add_physical_surface(obstacle, label=13)
geometry.add_physical_surface(rectangle.surface, label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
geometry.add_physical_line(rectangle.line_loop.lines, label=outer_marker)
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res,
hwall_n=res / 2,
thickness=2 * res)
geometry.add_background_field([field])
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="meshes/outfile.geo")
meshio.write(
"meshes/singlemesh.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
meshio.write(
"meshes/cf.xdmf",
meshio.Mesh(points=points,
cells={"triangle": cells["triangle"]},
cell_data={
"triangle": {
"name_to_read":
cell_data["triangle"]["gmsh:physical"]
}
}))
from pygmsh.built_in.geometry import Geometry from pygmsh import generate_mesh import meshio import dolfin import dolfin.io from dolfin.plotting import plot import matplotlib # Define input data from ufl import SpatialCoordinate, inner, grad, lhs, rhs, dot, exp, Measure, dx, ds from dolfin.fem import assemble_scalar from dolfin import FunctionSpace, TrialFunction, TestFunction, DirichletBC, Function, solve, cpp, fem geom = Geometry() mesh_ele_size = .02 p1 = geom.add_point([0.0, 0.0, 0], lcar=mesh_ele_size) p2 = geom.add_point([0.0, 1.0, 0], lcar=mesh_ele_size) p3 = geom.add_point([1.0, 1.0, 0], lcar=mesh_ele_size) p4 = geom.add_point([1.0, 0.0, 0], lcar=mesh_ele_size) p5 = geom.add_point([0.2, 0.5, 0], lcar=mesh_ele_size) p6 = geom.add_point([0.2, 0.7, 0], lcar=mesh_ele_size) p7 = geom.add_point([1.0, 0.5, 0], lcar=mesh_ele_size) p8 = geom.add_point([1.0, 0.7, 0], lcar=mesh_ele_size) l1 = geom.add_line(p1, p4) l2 = geom.add_line(p3, p2) l3 = geom.add_line(p2, p1) l4 = geom.add_line(p7, p5) l5 = geom.add_line(p5, p6) l6 = geom.add_line(p6, p8)
def front_mesh(res=0.025):
geometry = Geometry()
c = geometry.add_point((c_x, c_y, 0))
mesh_r = 5 * res # Width of mesh
# Elliptic obstacle
p1 = geometry.add_point((c_x - r_x, c_y, 0))
p2 = geometry.add_point((c_x, c_y + r_y, 0))
p3 = geometry.add_point((c_x + r_x, c_y, 0))
p4 = geometry.add_point((c_x, c_y - r_y, 0))
arc_1 = geometry.add_ellipse_arc(p1, c, p2, p2)
arc_2 = geometry.add_ellipse_arc(p2, c, p3, p3)
arc_3 = geometry.add_ellipse_arc(p3, c, p4, p4)
arc_4 = geometry.add_ellipse_arc(p4, c, p1, p1)
obstacle_loop = geometry.add_line_loop([arc_1, arc_2, arc_3, arc_4])
# Surrounding mesh
p1 = geometry.add_point((c_x - r_x - mesh_r, c_y, 0))
p2 = geometry.add_point((c_x, c_y + r_y + mesh_r, 0))
p3 = geometry.add_point((c_x + r_x + mesh_r, c_y, 0))
p4 = geometry.add_point((c_x, c_y - r_y - mesh_r, 0))
arc_5 = geometry.add_ellipse_arc(p1, c, p2, p2)
arc_6 = geometry.add_ellipse_arc(p2, c, p3, p3)
arc_7 = geometry.add_ellipse_arc(p3, c, p4, p4)
arc_8 = geometry.add_ellipse_arc(p4, c, p1, p1)
loop = geometry.add_line_loop([arc_5, arc_6, arc_7, arc_8])
mesh = geometry.add_plane_surface(loop, holes=[obstacle_loop])
geometry.add_physical_surface(mesh, label=12)
geometry.add_physical_line(loop.lines, label=outer_marker)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
# Create refined mesh around geometry
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res,
hwall_n=res / 2,
thickness=2 * res)
geometry.add_background_field([field])
# Generate mesh
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="meshes/test.geo")
# Save mesh and mesh-function to file
meshio.write(
"meshes/multimesh_1.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf_1.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
def background_mesh(res=0.025):
"""
Create rectangular background mesh for the Poisson problem
"""
geo = Geometry()
# Create points for square with two inlets and one outlet
points = []
points.append(geo.add_point((0, 0, 0), res))
points.append(geo.add_point((1, 0, 0), res))
points.append(geo.add_point((1, 1, 0), res))
points.append(geo.add_point(outlet[1], res))
points.append(geo.add_point(outlet[0], res))
points.append(geo.add_point((0, 1, 0), res))
points.append(geo.add_point(inlet1[1], res))
points.append(geo.add_point(inlet1[0], res))
points.append(geo.add_point(inlet0[1], res))
points.append(geo.add_point(inlet0[0], res))
# Connect points as lines
lines = []
for i in range(len(points) - 1):
lines.append(geo.add_line(points[i], points[i + 1]))
lines.append(geo.add_line(points[-1], points[0]))
# Create geometry
line_loop = geo.add_line_loop(lines)
square = geo.add_plane_surface(line_loop)
# Create cell and facet function
wall_lines = lines[0:3] + lines[4:6] + [lines[7]] + [lines[9]]
inlet0_lines = [lines[8]]
inlet1_lines = [lines[6]]
outlet_lines = [lines[3]]
geo.add_physical_surface([square], label=12)
geo.add_physical_line(inlet0_lines, label=inlet0_marker)
geo.add_physical_line(inlet1_lines, label=inlet1_marker)
geo.add_physical_line(outlet_lines, label=outlet_marker)
geo.add_physical_line(wall_lines, label=wall_marker)
# Create mesh
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geo, prune_z_0=True) #,
#geo_filename="meshes/tmp.geo")
meshio.write(
"meshes/multimesh_0.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf_0.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
from pygmsh.built_in.geometry import Geometry
from pygmsh import generate_mesh
import meshio
import dolfin
import dolfin.io
geom = Geometry()
mesh_ele_size = .1
p0 = geom.add_point([0, 0, 0], lcar=mesh_ele_size)
p1 = geom.add_point([1, 0, 0], lcar=mesh_ele_size)
p2 = geom.add_point([1, 1, 0], lcar=mesh_ele_size)
p3 = geom.add_point([0, 1, 0], lcar=mesh_ele_size)
l0 = geom.add_line(p0, p1)
l1 = geom.add_line(p1, p2)
l2 = geom.add_line(p2, p3)
l3 = geom.add_line(p3, p0)
ll = geom.add_line_loop(lines=[l0, l1, l2, l3])
ps = geom.add_plane_surface(ll)
# Tag line and surface
geom.add_physical(l3, label=444)
geom.add_physical(ps, label=456)
print("\n".join(geom._GMSH_CODE))
mesh = generate_mesh(geom)
points, cells, cell_data = mesh.points, mesh.cells, mesh.cell_data
meshio.write("input/mesh_2d.xdmf",
def background_mesh(res=0.025):
"""
Create rectangular background mesh for the Poisson problem
"""
geometry = Geometry()
# r_bottom = geometry.add_rectangle(0,L,0,H/2,0, res)
# r_top = geometry.add_rectangle(0,L,H/2,H,0, res)
square = geometry.add_rectangle(0, L, 0, H, 0, res)
geometry.add_physical_surface([square.surface], label=12)
geometry.add_physical_line([square.line_loop.lines[3]], label=inflow)
geometry.add_physical_line([square.line_loop.lines[1]], label=outflow)
geometry.add_physical_line(
[square.line_loop.lines[0], square.line_loop.lines[2]], label=walls)
# geometry.add_physical_surface([r_bottom.surface,
# r_top.surface],label=12)
# in_lines = [r_bottom.line_loop.lines[3],r_top.line_loop.lines[3]]
# geometry.add_physical_line(in_lines, label=inflow)
# out_lines = [r_bottom.line_loop.lines[1],r_top.line_loop.lines[1]]
# geometry.add_physical_line(out_lines, label=outflow)
# wall_lines = [r_bottom.line_loop.lines[0],r_top.line_loop.lines[2]]
# geometry.add_physical_line(wall_lines, label=walls)
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="meshes/tmp.geo")
meshio.write(
"meshes/multimesh_0.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf_0.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
def front_mesh(res=0.025):
geometry = Geometry()
mesh_r = width_scale * res
c = geometry.add_point((c_x, c_y, 0))
# Elliptic obstacle
p1 = geometry.add_point((c_x - r_x, c_y, 0))
p2 = geometry.add_point((c_x + r_x, c_y, 0))
p12 = geometry.add_point((c_x, c_y + 1.4 * r_x, 0))
p21 = geometry.add_point((c_x, c_y - 1.4 * r_x, 0))
arc_1 = geometry.add_spline([p1, p12, p2])
arc_2 = geometry.add_spline([p2, p21, p1])
# arc_1 = geometry.add_circle_arc(p1, c, p2)
# arc_2 = geometry.add_circle_arc(p2, c, p1)
# Surrounding mesh
p3 = geometry.add_point((c_x - r_x - mesh_r, c_y, 0))
p4 = geometry.add_point((c_x + r_x + mesh_r, c_y, 0))
p34 = geometry.add_point((c_x, c_y + 1.4 * r_x + mesh_r, 0))
p43 = geometry.add_point((c_x, c_y - 1.4 * r_x - mesh_r, 0))
arc_5 = geometry.add_spline([p3, p34, p4])
arc_6 = geometry.add_spline([p4, p43, p3])
# arc_5 = geometry.add_circle_arc(p3, c, p4)
# arc_6 = geometry.add_circle_arc(p4, c, p3)
line_front = geometry.add_line(p3, p1)
line_back = geometry.add_line(p2, p4)
surface_top = geometry.add_line_loop(
[line_front, arc_1, line_back, -arc_5])
surface_bottom = geometry.add_line_loop(
[line_front, -arc_2, line_back, arc_6])
obstacle_loop = geometry.add_line_loop([arc_1, arc_2])
top = geometry.add_plane_surface(surface_top)
bottom = geometry.add_plane_surface(surface_bottom)
geometry.add_physical_surface([top, bottom], label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
# Create refined mesh around geometry
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res,
hwall_n=res / 3,
thickness=2 * res)
geometry.add_background_field([field])
# Generate mesh
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="meshes/test.geo")
# Save mesh and mesh-function to file
meshio.write(
"meshes/multimesh_1.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf_1.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
def front_mesh_symmetric(res=0.025):
"""
Creates a donut mesh with symmetry line through y = c_y
"""
geometry = Geometry()
mesh_r = width_scale*res
c = geometry.add_point((c_x,c_y,0))
# Elliptic obstacle
p1 = geometry.add_point((c_x-r_x, c_y,0))
p2 = geometry.add_point((c_x+r_x, c_y,0))
# embed()
arc_1 = geometry.add_circle_arc(p1, c, p2)
arc_2 = geometry.add_circle_arc(p2, c, p1)
# Surrounding mesh
p3 = geometry.add_point((c_x-r_x-mesh_r, c_y,0))
p4 = geometry.add_point((c_x+r_x+mesh_r, c_y,0))
arc_5 = geometry.add_circle_arc(p3, c, p4)
arc_6 = geometry.add_circle_arc(p4, c, p3)
line_front = geometry.add_line(p3, p1)
line_back = geometry.add_line(p2, p4)
surface_top = geometry.add_line_loop([line_front, arc_1, line_back, -arc_5])
surface_bottom = geometry.add_line_loop([line_front, -arc_2, line_back,
arc_6])
obstacle_loop = geometry.add_line_loop([arc_1, arc_2])
outer_loop = geometry.add_line_loop([arc_5,arc_6])
top = geometry.add_plane_surface(surface_top)
bottom = geometry.add_plane_surface(surface_bottom)
geometry.add_physical_surface([top, bottom],label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
geometry.add_physical_line(outer_loop.lines, label=outer_marker)
# Create refined mesh around geometry
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res, hwall_n=res/3,
thickness=0.1*mesh_r)
geometry.add_background_field([field])
# Generate mesh
(points, cells, point_data,
cell_data, field_data) = generate_mesh(geometry, prune_z_0=True,
geo_filename="meshes/test.geo")
# Save mesh and mesh-function to file
meshio.write("multimesh_1.xdmf", meshio.Mesh(
points=points, cells={"triangle": cells["triangle"]}))
meshio.write("mf_1.xdmf", meshio.Mesh(
points=points, cells={"line": cells["line"]},
cell_data={"line": {"name_to_read":
cell_data["line"]["gmsh:physical"]}}))
import os
os.system("mv multimesh_1.* meshes/")
os.system("mv mf_1.* meshes/")
def single_mesh(res=0.025):
"""
Creates a single mesh containing a circular obstacle
"""
geometry = Geometry()
c = geometry.add_point((c_x, c_y, 0))
# Elliptic obstacle
p1 = geometry.add_point((c_x - r_x, c_y, 0))
p2 = geometry.add_point((c_x, c_y + r_x, 0))
p3 = geometry.add_point((c_x + r_x, c_y, 0))
p4 = geometry.add_point((c_x, c_y - r_x, 0))
arc_1 = geometry.add_ellipse_arc(p1, c, p2, p2)
arc_2 = geometry.add_ellipse_arc(p2, c, p3, p3)
arc_3 = geometry.add_ellipse_arc(p3, c, p4, p4)
arc_4 = geometry.add_ellipse_arc(p4, c, p1, p1)
obstacle_loop = geometry.add_line_loop([arc_1, arc_2, arc_3, arc_4])
rectangle = geometry.add_rectangle(0,
L,
0,
H,
0,
res,
holes=[obstacle_loop])
flow_list = [rectangle.line_loop.lines[3]]
obstacle_list = obstacle_loop.lines
walls_list = [rectangle.line_loop.lines[0], rectangle.line_loop.lines[2]]
geometry.add_physical_surface(rectangle.surface, label=12)
geometry.add_physical_line(flow_list, label=inflow)
geometry.add_physical_line(walls_list, label=walls)
geometry.add_physical_line([rectangle.line_loop.lines[1]], label=outflow)
geometry.add_physical_line(obstacle_list, label=obstacle)
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res,
hwall_n=res / 8,
thickness=res / 2)
geometry.add_background_field([field])
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="test.geo")
meshio.write(
"mesh.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"mf.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
def front_mesh_unsym(res=0.025):
"""
Creates unsymmetric donut mesh
"""
geometry = Geometry()
mesh_r = width_scale*res
c = geometry.add_point((c_x,c_y,0))
# Elliptic obstacle
p1 = geometry.add_point((c_x-r_x, c_y,0),lcar=res/2)
p2 = geometry.add_point((c_x+r_x, c_y,0),lcar=res/2)
arc_1 = geometry.add_circle_arc(p1, c, p2)
arc_2 = geometry.add_circle_arc(p2, c, p1)
# Surrounding mesh
p3 = geometry.add_point((c_x-r_x-mesh_r, c_y,0),lcar=res)
p4 = geometry.add_point((c_x+r_x+mesh_r, c_y,0),lcar=res)
arc_5 = geometry.add_circle_arc(p3, c, p4)
arc_6 = geometry.add_circle_arc(p4, c, p3)
obstacle_loop = geometry.add_line_loop([arc_1, arc_2])
outer_loop = geometry.add_line_loop([arc_5,arc_6])
donut = geometry.add_plane_surface(obstacle_loop, holes=[outer_loop])
geometry.add_physical_surface([donut],label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
geometry.add_physical_line(outer_loop.lines, label=outer_marker)
# Create refined mesh around geometry
# field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
# hfar=res, hwall_n=res/3,
# thickness=2*res)
# geometry.add_background_field([field])
# Generate mesh
(points, cells, point_data,
cell_data, field_data) = generate_mesh(geometry, prune_z_0=True,
geo_filename="meshes/test.geo")
# Save mesh and mesh-function to file
meshio.write("meshes/multimesh_1.xdmf", meshio.Mesh(
points=points, cells={"triangle": cells["triangle"]}))
meshio.write("meshes/mf_1.xdmf", meshio.Mesh(
points=points, cells={"line": cells["line"]},
cell_data={"line": {"name_to_read":
cell_data["line"]["gmsh:physical"]}}))
def background_mesh(res=0.025):
"""
Create rectangular background mesh for the Poisson problem
"""
geometry = Geometry()
square = geometry.add_rectangle(0,L,0,H,0, 5*res)
geometry.add_physical_surface([square.surface],label=12)
geometry.add_physical_line([square.line_loop.lines[3]], label=inflow)
geometry.add_physical_line([square.line_loop.lines[1]], label=outflow)
geometry.add_physical_line([square.line_loop.lines[0],
square.line_loop.lines[2]], label=walls)
p_c = geometry.add_point((c_x,c_y,0),lcar=0.1*res)
geometry.add_raw_code(["Field[1]=Attractor;",
"Field[1].NodesList={{ {} }};".format(p_c.id),
"Field[2]=Threshold;",
"Field[2].IField=1;",
"Field[2].LcMin={};".format(res),
"Field[2].LcMax={};".format(5*res),
"Field[2].DistMin={};".format(2*r_x),
"Field[2].DistMax={};".format(4*r_x),
"Field[3]=Min;",
"Field[3].FieldsList = {2};",
"Background Field = 3;"])
(points, cells, point_data,
cell_data, field_data) = generate_mesh(geometry, prune_z_0=True,dim=2,
geo_filename="meshes/tmp.geo")
meshio.write("multimesh_0.xdmf", meshio.Mesh(
points=points, cells={"triangle": cells["triangle"]}))
meshio.write("mf_0.xdmf", meshio.Mesh(
points=points, cells={"line": cells["line"]},
cell_data={"line": {"name_to_read":
cell_data["line"]["gmsh:physical"]}}))
import os
os.system("mv multimesh_0.* meshes/")
os.system("mv mf_0.* meshes/")
def front_mesh_wedge(res=0.025):
"""
Creates a wedged mesh with symmetry line through y = c_y
"""
geometry = Geometry()
mesh_r = width_scale*res
c = geometry.add_point((c_x,c_y,0))
# Elliptic obstacle
y_fac = 1
r_ =0.7
p1 = geometry.add_point((c_x-r_x, c_y,0),lcar=res/2)
pt1 = geometry.add_point((c_x-r_*r_x,c_y+y_fac*r_x,0),lcar=res/2)
pt2 = geometry.add_point((c_x+r_*r_x,c_y+y_fac*r_x,0),lcar=res/2)
pb1 = geometry.add_point((c_x-r_*r_x, c_y-y_fac*r_x,0),lcar=res/2)
pb2 = geometry.add_point((c_x+r_*r_x, c_y-y_fac*r_x,0),lcar=res/2)
p2 = geometry.add_point((c_x+r_x, c_y,0),lcar=res/2)
# embed()
arc_1 = geometry.add_bspline([p1, pt1,pt2, p2])
arc_2 = geometry.add_bspline([p2, pb2,pb1, p1])
# Surrounding mesh
p3 = geometry.add_point((c_x-r_x-mesh_r, c_y,0),lcar=res)
p4 = geometry.add_point((c_x+r_x+mesh_r, c_y,0),lcar=res)
pt_1 = geometry.add_point((c_x-r_*r_x*y_fac, c_y+y_fac*r_x+mesh_r,0),
lcar=res)
pt_2 = geometry.add_point((c_x+r_*r_x*y_fac, c_y+y_fac*r_x+mesh_r,0)
,lcar=res)
pb_1 = geometry.add_point((c_x-r_*r_x*y_fac, c_y-y_fac*r_x-mesh_r,0),
lcar=res)
pb_2 = geometry.add_point((c_x+r_*r_x*y_fac, c_y-y_fac*r_x-mesh_r,0),
lcar=res)
arc_5 = geometry.add_bspline([p3, pt_1, pt_2, p4])
arc_6 = geometry.add_bspline([p4, pb_2, pb_1, p3])
obstacle_loop = geometry.add_line_loop([arc_1, arc_2])
outer_loop = geometry.add_line_loop([arc_5,arc_6])
donut = geometry.add_plane_surface(obstacle_loop, holes = [outer_loop])
geometry.add_physical_surface([donut],label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
geometry.add_physical_line(outer_loop.lines, label=outer_marker)
# Generate mesh
(points, cells, point_data,
cell_data, field_data) = generate_mesh(geometry, prune_z_0=True,
geo_filename="meshes/test.geo")
# Save mesh and mesh-function to file
meshio.write("multimesh_1.xdmf", meshio.Mesh(
points=points, cells={"triangle": cells["triangle"]}))
meshio.write("mf_1.xdmf", meshio.Mesh(
points=points, cells={"line": cells["line"]},
cell_data={"line": {"name_to_read":
cell_data["line"]["gmsh:physical"]}}))
import os
os.system("mv multimesh_1.* meshes/")
os.system("mv mf_1.* meshes/")
def single_mesh(res=0.025):
"""
Create rectangular background mesh for the Poisson problem
"""
geometry = Geometry()
c = geometry.add_point((c_x, c_y, 0))
mesh_r = 5 * res # Width of mesh
# Elliptic obstacle
p1 = geometry.add_point((c_x - r_x, c_y, 0))
p2 = geometry.add_point((c_x, c_y + r_y, 0))
p3 = geometry.add_point((c_x + r_x, c_y, 0))
p4 = geometry.add_point((c_x, c_y - r_y, 0))
arc_1 = geometry.add_ellipse_arc(p1, c, p2, p2)
arc_2 = geometry.add_ellipse_arc(p2, c, p3, p3)
arc_3 = geometry.add_ellipse_arc(p3, c, p4, p4)
arc_4 = geometry.add_ellipse_arc(p4, c, p1, p1)
obstacle_loop = geometry.add_line_loop([arc_1, arc_2, arc_3, arc_4])
# Surrounding mesh
rectangle = geometry.add_rectangle(0,
L,
0,
H,
0,
res,
holes=[obstacle_loop])
geometry.add_physical_surface(rectangle.surface, label=12)
geometry.add_physical_line(obstacle_loop.lines, label=inner_marker)
geometry.add_physical_line(rectangle.line_loop.lines, label=outer_marker)
# Create refined mesh around geometry
field = geometry.add_boundary_layer(edges_list=obstacle_loop.lines,
hfar=res,
hwall_n=res / 2,
thickness=2 * res)
geometry.add_background_field([field])
# Generate mesh
(points, cells, point_data, cell_data,
field_data) = generate_mesh(geometry,
prune_z_0=True,
geo_filename="meshes/test_single.geo")
# Save mesh and mesh-function to file
meshio.write(
"meshes/singlemesh.xdmf",
meshio.Mesh(points=points, cells={"triangle": cells["triangle"]}))
meshio.write(
"meshes/mf.xdmf",
meshio.Mesh(points=points,
cells={"line": cells["line"]},
cell_data={
"line": {
"name_to_read": cell_data["line"]["gmsh:physical"]
}
}))
from pygmsh.built_in.geometry import Geometry
from pygmsh import generate_mesh
import dolfin
import dolfin.io
geom = Geometry()
mesh_ele_size = 0.5
p0 = geom.add_point([0, 0, 0], lcar=mesh_ele_size)
p1 = geom.add_point([1, 0, 0], lcar=mesh_ele_size)
p2 = geom.add_point([1, 1, 0], lcar=mesh_ele_size)
p3 = geom.add_point([0, 1, 0], lcar=mesh_ele_size)
l0 = geom.add_line(p0, p1)
l1 = geom.add_line(p1, p2)
l2 = geom.add_line(p2, p3)
l3 = geom.add_line(p3, p0)
ll = geom.add_line_loop(lines=[l0, l1, l2, l3])
ps = geom.add_plane_surface(ll)
# Tag line and surface
geom.add_physical(l0, label="BOTTOM")
geom.add_physical(l1, label="RIGHT")
geom.add_physical(l2, label="TOP")
geom.add_physical(l3, label="LEFT")
geom.add_physical(ps, label="DOMAIN")
# print("\n".join(geom._GMSH_CODE))
mesh = generate_mesh(geom)
