def initial_mesh(self):
mesh = self.coarse_mesh()
for cycle in range(self.initial_hot_wall_refinement_cycles):
edge_markers = fenics.MeshFunction("bool", mesh, 1, False)
self.hot_wall.mark(edge_markers, True)
fenics.adapt(mesh, edge_markers)
mesh = mesh.child()
return mesh
def refine_initial_mesh(self):
""" Refine near the hot wall. """
class HotWall(fenics.SubDomain):
def inside(self, x, on_boundary):
return on_boundary and fenics.near(x[0], 0.)
hot_wall = HotWall()
for i in range(self.initial_hot_wall_refinement_cycles):
edge_markers = fenics.MeshFunction("bool", self.mesh, 1, False)
hot_wall.mark(edge_markers, True)
fenics.adapt(self.mesh, edge_markers)
self.mesh = self.mesh.child()
def refine_initial_mesh(self):
""" Refine near the phase-change interface. """
y_pci = self.y_pci
class PhaseInterface(fenics.SubDomain):
def inside(self, x, on_boundary):
return fenics.near(x[1], y_pci)
phase_interface = PhaseInterface()
for i in range(self.pci_refinement_cycles):
edge_markers = fenics.MeshFunction("bool", self.mesh, 1, False)
phase_interface.mark(edge_markers, True)
fenics.adapt(self.mesh, edge_markers)
self.mesh = self.mesh.child(
) # Does this break references? Can we do this a different way?
def test_variable_viscosity__nightly():
lid = "near(x[1], 1.)"
ymin = -0.25
fixed_walls = "near(x[0], 0.) | near(x[0], 1.) | near(x[1], '+str(ymin)+')"
left_middle = "near(x[0], 0.) && near(x[1], 0.5)"
output_dir = "output/test_variable_viscosity"
mesh = fenics.RectangleMesh(fenics.Point(0., ymin), fenics.Point(1., 1.), 20, 25, 'crossed')
# Refine the initial PCI.
initial_pci_refinement_cycles = 4
class PCI(fenics.SubDomain):
def inside(self, x, on_boundary):
return fenics.near(x[1], 0.)
pci = PCI()
for i in range(initial_pci_refinement_cycles):
edge_markers = fenics.EdgeFunction("bool", mesh)
pci.mark(edge_markers, True)
fenics.adapt(mesh, edge_markers)
mesh = mesh.child()
# Run the simulation.
w, mesh = phaseflow.run(
mesh = mesh,
end_time = 20.,
time_step_size = 1.,
stop_when_steady = True,
steady_relative_tolerance = 1.e-4,
thermal_conductivity = 0.,
liquid_viscosity = 0.01,
solid_viscosity = 1.e6,
temperature_of_fusion = -0.01,
regularization_smoothing_factor = 0.01,
gravity = (0., 0.),
stefan_number = 1.e16,
adaptive = True,
output_dir = output_dir,
initial_values_expression = (lid, "0.", "0.", "1. - 2.*(x[1] <= 0.)"),
boundary_conditions = [
{'subspace': 0, 'value_expression': ("1.", "0."), 'degree': 3, 'location_expression': lid, 'method': 'topological'},
{'subspace': 0, 'value_expression': ("0.", "0."), 'degree': 3, 'location_expression': fixed_walls, 'method': 'topological'},
{'subspace': 1, 'value_expression': "0.", 'degree': 2, 'location_expression': left_middle, 'method': 'pointwise'}])
# Verify against the known solution.
verify_against_ghia1982(w, mesh)
def inside(self, x, on_boundary):
return on_boundary and fenics.near(x[0], 0.)
hot_wall = HotWall()
initial_hot_wall_refinement_cycles = 6
for cycle in range(initial_hot_wall_refinement_cycles):
edge_markers = fenics.MeshFunction("bool", mesh, 1, False)
hot_wall.mark(edge_markers, True)
fenics.adapt(mesh, edge_markers)
mesh = mesh.child()
P1 = fenics.FiniteElement('P', mesh.ufl_cell(), 1)
P2 = fenics.VectorElement('P', mesh.ufl_cell(), 2)
mixed_element = fenics.MixedElement([P1, P2, P1])
W = fenics.FunctionSpace(mesh, mixed_element)
psi_p, psi_u, psi_T = fenics.TestFunctions(W)
w = fenics.Function(W)
def melt_toy_pcm(output_dir="output/test_melt_toy_pcm/",
restart=False,
restart_filepath='',
start_time=0.):
# Make the mesh.
initial_mesh_size = 1
mesh = fenics.UnitSquareMesh(initial_mesh_size, initial_mesh_size,
'crossed')
initial_hot_wall_refinement_cycles = 6
class HotWall(fenics.SubDomain):
def inside(self, x, on_boundary):
return on_boundary and fenics.near(x[0], 0.)
hot_wall = HotWall()
for i in range(initial_hot_wall_refinement_cycles):
edge_markers = fenics.EdgeFunction("bool", mesh)
hot_wall.mark(edge_markers, True)
fenics.adapt(mesh, edge_markers)
mesh = mesh.child()
# Run phaseflow.
T_hot = 1.
T_cold = -0.1
w, mesh = phaseflow.run(
stefan_number=1.,
rayleigh_number=1.e6,
prandtl_number=0.71,
solid_viscosity=1.e4,
liquid_viscosity=1.,
mesh=mesh,
time_step_size=1.e-3,
start_time=start_time,
end_time=0.02,
stop_when_steady=True,
temperature_of_fusion=T_f,
regularization_smoothing_factor=0.025,
adaptive=True,
adaptive_metric='phase_only',
adaptive_solver_tolerance=1.e-4,
nlp_relative_tolerance=1.e-8,
initial_values_expression=("0.", "0.", "0.",
"(" + str(T_hot) + " - " + str(T_cold) +
")*(x[0] < 0.001) + " + str(T_cold)),
boundary_conditions=[{
'subspace': 0,
'value_expression': ("0.", "0."),
'degree': 3,
'location_expression':
"near(x[0], 0.) | near(x[0], 1.) | near(x[1], 0.) | near(x[1], 1.)",
'method': "topological"
}, {
'subspace': 2,
'value_expression': str(T_hot),
'degree': 2,
'location_expression': "near(x[0], 0.)",
'method': "topological"
}, {
'subspace': 2,
'value_expression': str(T_cold),
'degree': 2,
'location_expression': "near(x[0], 1.)",
'method': "topological"
}],
output_dir=output_dir,
restart=restart,
restart_filepath=restart_filepath)
return w