(modules/phase_field/examples/nucleation/refine.i)
#
# Example derived from cahn_hilliard.i demonstrating the use of Adaptivity
# with the DiscreteNucleation system. The DiscreteNucleationMarker triggers
# mesh refinement for the nucleus geometry. It is up to the user to specify
# refinement for the physics. In this example this is done using a GradientJumpIndicator
# with a ValueThresholdMarker. The nucleation system marker and the physics marker
# must be combined using a ComboMarker to combine their effect.
#
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
ny = 10
xmax = 500
ymax = 500
elem_type = QUAD
[]
[Modules]
[./PhaseField]
[./Conserved]
[./c]
free_energy = F
mobility = M
kappa = kappa_c
solve_type = REVERSE_SPLIT
[../]
[../]
[../]
[]
[ICs]
[./c_IC]
type = ConstantIC
variable = c
value = 0.2
[../]
[]
[Materials]
[./pfmobility]
type = GenericConstantMaterial
prop_names = 'M kappa_c'
prop_values = '1 25'
[../]
[./chemical_free_energy]
# simple double well free energy
type = DerivativeParsedMaterial
f_name = Fc
args = 'c'
constant_names = 'barr_height cv_eq'
constant_expressions = '0.1 0'
function = 16*barr_height*c^2*(1-c)^2 # +0.01*(c*plog(c,0.005)+(1-c)*plog(1-c,0.005))
derivative_order = 2
outputs = exodus
[../]
[./probability]
# This is a made up toy nucleation rate it should be replaced by
# classical nucleation theory in a real simulation.
type = ParsedMaterial
f_name = P
args = c
function = 'if(c<0.21,c*1e-8,0)'
outputs = exodus
[../]
[./nucleation]
# The nucleation material is configured to insert nuclei into the free energy
# tht force the concentration to go to 0.95, and holds this enforcement for 500
# time units.
type = DiscreteNucleation
f_name = Fn
op_names = c
op_values = 0.90
penalty = 5
penalty_mode = MIN
map = map
outputs = exodus
[../]
[./free_energy]
# add the chemical and nucleation free energy contributions together
type = DerivativeSumMaterial
derivative_order = 2
args = c
sum_materials = 'Fc Fn'
[../]
[]
[UserObjects]
[./inserter]
# The inserter runs at the end of each time step to add nucleation events
# that happened during the timestep (if it converged) to the list of nuclei
type = DiscreteNucleationInserter
hold_time = 50
probability = P
radius = 10
[../]
[./map]
# The map UO runs at the beginning of a timestep and generates a per-element/qp
# map of nucleus locations. The map is only regenerated if the mesh changed or
# the list of nuclei was modified.
# The map converts the nucleation points into finite area objects with a given radius.
type = DiscreteNucleationMap
periodic = c
inserter = inserter
[../]
[]
[Preconditioning]
[./SMP]
type = SMP
full = true
[../]
[]
[BCs]
[./Periodic]
[./all]
auto_direction = 'x y'
[../]
[../]
[]
[Postprocessors]
[./dt]
type = TimestepSize
[../]
[./ndof]
type = NumDOFs
[../]
[./rate]
type = DiscreteNucleationData
value = RATE
inserter = inserter
[../]
[./dtnuc]
type = DiscreteNucleationTimeStep
inserter = inserter
p2nucleus = 0.0005
dt_max = 10
[../]
[./update]
type = DiscreteNucleationData
value = UPDATE
inserter = inserter
[../]
[./count]
type = DiscreteNucleationData
value = COUNT
inserter = inserter
[../]
[]
[Adaptivity]
[./Indicators]
[./jump]
type = GradientJumpIndicator
variable = c
[../]
[../]
[./Markers]
[./nuc]
type = DiscreteNucleationMarker
map = map
[../]
[./grad]
type = ValueThresholdMarker
variable = jump
coarsen = 0.1
refine = 0.2
[../]
[./combo]
type = ComboMarker
markers = 'nuc grad'
[../]
[../]
marker = combo
cycles_per_step = 3
recompute_markers_during_cycles = true
max_h_level = 3
[]
[Executioner]
type = Transient
scheme = bdf2
solve_type = 'PJFNK'
petsc_options_iname = '-pc_type -sub_pc_type'
petsc_options_value = 'asm lu '
nl_max_its = 20
l_tol = 1.0e-4
nl_rel_tol = 1.0e-10
nl_abs_tol = 1.0e-10
start_time = 0.0
num_steps = 120
[./TimeStepper]
type = IterationAdaptiveDT
dt = 10
growth_factor = 1.5
cutback_factor = 0.5
optimal_iterations = 8
iteration_window = 2
timestep_limiting_postprocessor = dtnuc
[../]
[]
[Outputs]
exodus = true
csv = true
print_linear_residuals = false
[]