def setup():
vertices = numpy.zeros((8, 2))
vertices[0] = [0, 0]
for i in range(0, 7):
vertices[i + 1] = [
math.cos(cornerAngle / 6 * math.pi / 180 * i),
math.sin(cornerAngle / 6 * math.pi / 180 * i)
]
triangles = numpy.array([[2, 1, 0], [0, 3, 2], [4, 3, 0], [0, 5, 4],
[6, 5, 0], [0, 7, 6]])
domain = {"vertices": vertices, "simplices": triangles}
gridView = adaptiveGridView(leafGridView(domain))
gridView.hierarchicalGrid.globalRefine(2)
space = solutionSpace(gridView, order=order)
from dune.fem.scheme import galerkin as solutionScheme
u = TrialFunction(space)
v = TestFunction(space)
x = SpatialCoordinate(space.cell())
# exact solution for this angle
Phi = cornerAngle / 180 * pi
phi = atan_2(x[1], x[0]) + conditional(x[1] < 0, 2 * pi, 0)
exact = dot(x, x)**(pi / 2 / Phi) * sin(pi / Phi * phi)
a = dot(grad(u), grad(v)) * dx
# set up the scheme
laplace = solutionScheme(
[a == 0, DirichletBC(space, exact, 1)],
solver="cg",
parameters={"newton.linear.preconditioning.method": "jacobi"})
uh = space.interpolate(0, name="solution")
return uh, exact, laplace
T = 3 dt = 0.005 t = 0 # <markdowncell> # We use *gmsh* to define the domain and then set up a first order # scalar Lagrange space which we will use both for $\psi$ and $p$. We can # construct general grids by either defining the grids directly in Python # (as demonstrated in the following example) or by reading the grid from # files using readers provided by Dune, e.g., Dune Grid Format (dgf) files # or Gmsh files. # <codecell> domain = (reader.gmsh, "wave_tank.msh") gridView = leafGridView( domain, dimgrid=2 ) gridView.hierarchicalGrid.loadBalance() V = solutionSpace(gridView, order=1, storage="fem") p = V.interpolate(0,name="p") phi = V.interpolate(0,name="phi") pVec = p.as_numpy phiVec = phi.as_numpy # <markdowncell> # Next we define an operator for the stiffness matrix including the # boundary condition which are time dependent so we use a `Constant` for # this. We use the `BoxDirichletBC` class which is derived from the more # general `DirichletBC` class which takes a function space, the boundary # function $g$ as a ufl expression, and finally a description of the part
import ufl
from ufl import grad, dot, dx, inner, Identity, sqrt, sin, pi, cos
import dune.ufl
import dune.grid
import dune.fem
from dune.alugrid import aluConformGrid as leafGridView
from dune.fem.view import geometryGridView
from dune.fem.space import lagrange as solutionSpace
from dune.fem.scheme import galerkin as solutionScheme
order = 3
storage = "istl"
# setup reference surface
referenceView = leafGridView("sphere.dgf", dimgrid=2, dimworld=3)
space = solutionSpace(referenceView,
dimRange=referenceView.dimWorld,
order=order,
storage=storage)
# setup deformed surface
x = ufl.SpatialCoordinate(space)
# positions = space.interpolate(x, name="position")
positions = space.interpolate(
x * (1 + 0.5 * sin(2 * pi * (x[0] + x[1])) * cos(0.25 * pi * x[2])),
name="position")
gridView = geometryGridView(positions)
space = solutionSpace(gridView,
dimRange=gridView.dimWorld,
order=order,
storage=storage)
# <codecell>
import time
import dune.fem as fem
from dune.grid import cartesianDomain
from dune.alugrid import aluConformGrid as leafGridView
from dune.fem.view import adaptiveLeafGridView as adaptiveGridView
from dune.fem.space import lagrange as solutionSpace
fem.parameter.append({"fem.verboserank": -1})
order = 1
dimDomain = 2 # we are solving this in 2D
dimRange = 2 # we have a system with two unknowns
domain = cartesianDomain(
[4, 4], [8, 8], [40, 40]) # fails with 20x20 in adapt due to petsc error
gridView = adaptiveGridView(leafGridView(domain, dimgrid=dimDomain))
space = solutionSpace(gridView,
dimRange=dimRange,
order=order,
storage="petscadapt")
# <markdowncell>
# We want to solve the following system of equations of variables $\phi$ (phase field) and $T$ (temperature field)
#
# \begin{gather*}
# \tau \frac{\partial \phi}{\partial t} = \nabla \cdot D \nabla \phi + \phi(1-\phi)m(\phi, T), \\
# \frac{\partial T}{\partial t} = D_T \nabla^2 T + \frac{\partial \phi}{\partial t},
# \end{gather*}
#
# where $D_T$ = 2.25, m is given by
#
from ufl import *
from dune.fem import spaceAdapt, adapt
from dune.grid import cartesianDomain, gridFunction
from dune.alugrid import aluConformGrid as leafGridView
from dune.fem.view import adaptiveLeafGridView as adaptiveGridView
from dune.fem import parameter, doerflerMark, globalRefine
from dune.fem.function import levelFunction
from dune.ufl import Space
import dune.create as create
parameter.append({"fem.verboserank": 0})
domain = cartesianDomain([0, 0], [1, 1], [16, 16])
grid = adaptiveGridView(leafGridView(domain))
space = create.space("lagrangehp", grid, maxOrder=4, storage="istl")
u = TrialFunction(space)
v = TestFunction(space)
x = SpatialCoordinate(space)
n = FacetNormal(space)
mu = 20 * 16
hT = MaxCellEdgeLength(space)
hS = avg(MaxFacetEdgeLength(space))
hs = MaxFacetEdgeLength(space)('+')
diffusiveFlux = lambda w, d: d
source = -sin(pi * x[0]) * sin(6 * pi * x[1])
a = (inner(diffusiveFlux(u, grad(u)), grad(v)) + source * v) * dx
from ufl import SpatialCoordinate, dot
from dune.grid import cartesianDomain
from dune.alugrid import aluConformGrid as leafGridView
from dune.fem.view import filteredGridView
from dune.fem.space import lagrange
gridView = leafGridView( cartesianDomain([0,0],[1,1],[16,16]) )
filteredView = filteredGridView(gridView, lambda e: e.geometry.center.two_norm > 0.5, domainId=1)
space = lagrange(filteredView, order=2)
x = SpatialCoordinate(space)
solution = space.interpolate(dot(x,x),name="solution")
solution.plot()
print("number of dofs:", solution.size,\
"integral over filtered domain",solution.integrate())
filteredView = filteredGridView(gridView, lambda e: e.geometry.center.two_norm < 0.5, domainId=1,
useFilteredIndexSet=True)
space = lagrange(filteredView, order=2)
x = SpatialCoordinate(space)
solution = space.interpolate(dot(x,x),name="solution")
solution.plot()
print("number of dofs:", solution.size,\
"integral over filtered domain",solution.integrate())
space = lagrange(gridView, order=2)
solution = space.interpolate(dot(x,x),name="solution")
solution.plot()
print("number of dofs:", solution.size,\
"integral over filtered domain",solution.integrate())
inner, dot, div, grad, dx, as_vector, transpose, Identity
from dune.ufl import Constant, DirichletBC
from dune.fem.space import lagrange as lagrangeSpace
from dune.fem.operator import galerkin as galerkinOperator
from dune.fem.operator import linear as linearOperator
from dune.fem.scheme import galerkin as galerkinScheme
from dune.fem import parameter
parameter.append({"fem.verboserank": 0})
order = 2
# Note: structuredGrid fails in precon step!
# grid = structuredGrid([0,0],[3,1],[30,10])
from dune.alugrid import aluCubeGrid as leafGridView
grid = leafGridView( cartesianDomain([0,0],[3,1],[30,10]) )
spcU = lagrangeSpace(grid, dimRange=grid.dimension, order=order, storage="petsc")
spcP = lagrangeSpace(grid, dimRange=1, order=order-1, storage="petsc")
cell = spcU.cell()
x = SpatialCoordinate(cell)
mu = Constant(0.1, "mu")
nu = Constant(0.01, "nu")
u = TrialFunction(spcU)
v = TestFunction(spcU)
p = TrialFunction(spcP)
q = TestFunction(spcP)
exact_u = as_vector( [x[1] * (1.-x[1]), 0] )
exact_p = as_vector( [ (-2*x[0] + 2)*mu ] )
f = as_vector( [0,]*grid.dimension )
