def __init__(
self,
array_context: ArrayContext,
mesh: Mesh,
order=None,
discr_tag_to_group_factory=None,
mpi_communicator=None,
# FIXME: `quad_tag_to_group_factory` is deprecated
quad_tag_to_group_factory=None):
"""
:arg discr_tag_to_group_factory: A mapping from discretization tags
(typically one of: :class:`grudge.dof_desc.DISCR_TAG_BASE`,
:class:`grudge.dof_desc.DISCR_TAG_MODAL`, or
:class:`grudge.dof_desc.DISCR_TAG_QUAD`) to a
:class:`~meshmode.discretization.poly_element.ElementGroupFactory`
indicating with which type of discretization the operations are
to be carried out, or *None* to indicate that operations with this
discretization tag should be carried out with the standard volume
discretization.
"""
if (quad_tag_to_group_factory is not None
and discr_tag_to_group_factory is not None):
raise ValueError(
"Both `quad_tag_to_group_factory` and `discr_tag_to_group_factory` "
"are specified. Use `discr_tag_to_group_factory` instead.")
# FIXME: `quad_tag_to_group_factory` is deprecated
if (quad_tag_to_group_factory is not None
and discr_tag_to_group_factory is None):
warn(
"`quad_tag_to_group_factory` is a deprecated kwarg and will "
"be dropped in version 2022.x. Use `discr_tag_to_group_factory` "
"instead.",
DeprecationWarning,
stacklevel=2)
discr_tag_to_group_factory = quad_tag_to_group_factory
self._setup_actx = array_context.clone()
from meshmode.discretization.poly_element import \
default_simplex_group_factory
if discr_tag_to_group_factory is None:
if order is None:
raise TypeError(
"one of 'order' and 'discr_tag_to_group_factory' must be given"
)
discr_tag_to_group_factory = {
DISCR_TAG_BASE:
default_simplex_group_factory(base_dim=mesh.dim, order=order)
}
else:
if order is not None:
discr_tag_to_group_factory = discr_tag_to_group_factory.copy()
if DISCR_TAG_BASE in discr_tag_to_group_factory:
raise ValueError(
"if 'order' is given, 'discr_tag_to_group_factory' must "
"not have a key of DISCR_TAG_BASE")
discr_tag_to_group_factory[DISCR_TAG_BASE] = \
default_simplex_group_factory(base_dim=mesh.dim, order=order)
# Modal discr should always come from the base discretization
discr_tag_to_group_factory[DISCR_TAG_MODAL] = \
_generate_modal_group_factory(
discr_tag_to_group_factory[DISCR_TAG_BASE]
)
self.discr_tag_to_group_factory = discr_tag_to_group_factory
from meshmode.discretization import Discretization
self._volume_discr = Discretization(
array_context, mesh,
self.group_factory_for_discretization_tag(DISCR_TAG_BASE))
# NOTE: Can be removed when symbolics are completely removed
# {{{ management of discretization-scoped common subexpressions
from pytools import UniqueNameGenerator
self._discr_scoped_name_gen = UniqueNameGenerator()
self._discr_scoped_subexpr_to_name = {}
self._discr_scoped_subexpr_name_to_value = {}
# }}}
self._dist_boundary_connections = \
self._set_up_distributed_communication(
mpi_communicator, array_context)
self.mpi_communicator = mpi_communicator
def main(ctx_factory=cl.create_some_context, use_logmgr=True,
use_overintegration=False,
use_leap=False, use_profiling=False, casename=None,
rst_filename=None, actx_class=PyOpenCLArrayContext):
"""Drive the example."""
cl_ctx = ctx_factory()
if casename is None:
casename = "mirgecom"
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
num_parts = comm.Get_size()
from mirgecom.simutil import global_reduce as _global_reduce
global_reduce = partial(_global_reduce, comm=comm)
logmgr = initialize_logmgr(use_logmgr,
filename=f"{casename}.sqlite", mode="wu", mpi_comm=comm)
if use_profiling:
queue = cl.CommandQueue(
cl_ctx, properties=cl.command_queue_properties.PROFILING_ENABLE)
else:
queue = cl.CommandQueue(cl_ctx)
actx = actx_class(
queue,
allocator=cl_tools.MemoryPool(cl_tools.ImmediateAllocator(queue)))
# timestepping control
current_step = 0
if use_leap:
from leap.rk import RK4MethodBuilder
timestepper = RK4MethodBuilder("state")
else:
timestepper = rk4_step
t_final = 0.1
current_cfl = 1.0
current_dt = .01
current_t = 0
constant_cfl = False
# some i/o frequencies
nstatus = 1
nrestart = 5
nviz = 10
nhealth = 1
dim = 3
rst_path = "restart_data/"
rst_pattern = (
rst_path + "{cname}-{step:04d}-{rank:04d}.pkl"
)
if rst_filename: # read the grid from restart data
rst_filename = f"{rst_filename}-{rank:04d}.pkl"
from mirgecom.restart import read_restart_data
restart_data = read_restart_data(actx, rst_filename)
local_mesh = restart_data["local_mesh"]
local_nelements = local_mesh.nelements
global_nelements = restart_data["global_nelements"]
assert restart_data["num_parts"] == num_parts
else: # generate the grid from scratch
from meshmode.mesh.generation import generate_regular_rect_mesh
box_ll = -1
box_ur = 1
nel_1d = 16
generate_mesh = partial(generate_regular_rect_mesh, a=(box_ll,)*dim,
b=(box_ur,) * dim, nelements_per_axis=(nel_1d,)*dim)
local_mesh, global_nelements = generate_and_distribute_mesh(comm,
generate_mesh)
local_nelements = local_mesh.nelements
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
order = 1
discr = EagerDGDiscretization(
actx, local_mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(
base_dim=local_mesh.dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
},
mpi_communicator=comm
)
nodes = thaw(discr.nodes(), actx)
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
vis_timer = None
if logmgr:
logmgr_add_cl_device_info(logmgr, queue)
logmgr_add_device_memory_usage(logmgr, queue)
logmgr_add_many_discretization_quantities(logmgr, discr, dim,
extract_vars_for_logging, units_for_logging)
vis_timer = IntervalTimer("t_vis", "Time spent visualizing")
logmgr.add_quantity(vis_timer)
logmgr.add_watches([
("step.max", "step = {value}, "),
("t_sim.max", "sim time: {value:1.6e} s\n"),
("min_pressure", "------- P (min, max) (Pa) = ({value:1.9e}, "),
("max_pressure", "{value:1.9e})\n"),
("t_step.max", "------- step walltime: {value:6g} s, "),
("t_log.max", "log walltime: {value:6g} s")
])
eos = IdealSingleGas()
gas_model = GasModel(eos=eos)
vel = np.zeros(shape=(dim,))
orig = np.zeros(shape=(dim,))
initializer = Lump(dim=dim, center=orig, velocity=vel, rhoamp=0.0)
wall = AdiabaticSlipBoundary()
boundaries = {BTAG_ALL: wall}
uniform_state = initializer(nodes)
acoustic_pulse = AcousticPulse(dim=dim, amplitude=1.0, width=.1,
center=orig)
if rst_filename:
current_t = restart_data["t"]
current_step = restart_data["step"]
current_cv = restart_data["cv"]
if logmgr:
from mirgecom.logging_quantities import logmgr_set_time
logmgr_set_time(logmgr, current_step, current_t)
else:
# Set the current state from time 0
current_cv = acoustic_pulse(x_vec=nodes, cv=uniform_state, eos=eos)
current_state = make_fluid_state(current_cv, gas_model)
visualizer = make_visualizer(discr)
initname = "pulse"
eosname = eos.__class__.__name__
init_message = make_init_message(dim=dim, order=order,
nelements=local_nelements,
global_nelements=global_nelements,
dt=current_dt, t_final=t_final, nstatus=nstatus,
nviz=nviz, cfl=current_cfl,
constant_cfl=constant_cfl, initname=initname,
eosname=eosname, casename=casename)
if rank == 0:
logger.info(init_message)
def my_write_viz(step, t, state, dv=None):
if dv is None:
dv = eos.dependent_vars(state)
viz_fields = [("cv", state),
("dv", dv)]
from mirgecom.simutil import write_visfile
write_visfile(discr, viz_fields, visualizer, vizname=casename,
step=step, t=t, overwrite=True, vis_timer=vis_timer)
def my_write_restart(step, t, state):
rst_fname = rst_pattern.format(cname=casename, step=step, rank=rank)
if rst_fname != rst_filename:
rst_data = {
"local_mesh": local_mesh,
"cv": state,
"t": t,
"step": step,
"order": order,
"global_nelements": global_nelements,
"num_parts": num_parts
}
from mirgecom.restart import write_restart_file
write_restart_file(actx, rst_data, rst_fname, comm)
def my_health_check(pressure):
health_error = False
from mirgecom.simutil import check_naninf_local, check_range_local
if check_naninf_local(discr, "vol", pressure) \
or check_range_local(discr, "vol", pressure, .8, 1.5):
health_error = True
logger.info(f"{rank=}: Invalid pressure data found.")
return health_error
def my_pre_step(step, t, dt, state):
fluid_state = make_fluid_state(state, gas_model)
dv = fluid_state.dv
try:
if logmgr:
logmgr.tick_before()
from mirgecom.simutil import check_step
do_viz = check_step(step=step, interval=nviz)
do_restart = check_step(step=step, interval=nrestart)
do_health = check_step(step=step, interval=nhealth)
if do_health:
health_errors = global_reduce(my_health_check(dv.pressure), op="lor")
if health_errors:
if rank == 0:
logger.info("Fluid solution failed health check.")
raise MyRuntimeError("Failed simulation health check.")
if do_restart:
my_write_restart(step=step, t=t, state=state)
if do_viz:
my_write_viz(step=step, t=t, state=state, dv=dv)
except MyRuntimeError:
if rank == 0:
logger.info("Errors detected; attempting graceful exit.")
my_write_viz(step=step, t=t, state=state)
my_write_restart(step=step, t=t, state=state)
raise
dt = get_sim_timestep(discr, fluid_state, t, dt, current_cfl, t_final,
constant_cfl)
return state, dt
def my_post_step(step, t, dt, state):
# Logmgr needs to know about EOS, dt, dim?
# imo this is a design/scope flaw
if logmgr:
set_dt(logmgr, dt)
set_sim_state(logmgr, dim, state, eos)
logmgr.tick_after()
return state, dt
def my_rhs(t, state):
fluid_state = make_fluid_state(cv=state, gas_model=gas_model)
return euler_operator(discr, state=fluid_state, time=t,
boundaries=boundaries,
gas_model=gas_model,
quadrature_tag=quadrature_tag)
current_dt = get_sim_timestep(discr, current_state, current_t, current_dt,
current_cfl, t_final, constant_cfl)
current_step, current_t, current_cv = \
advance_state(rhs=my_rhs, timestepper=timestepper,
pre_step_callback=my_pre_step,
post_step_callback=my_post_step, dt=current_dt,
state=current_cv, t=current_t, t_final=t_final)
# Dump the final data
if rank == 0:
logger.info("Checkpointing final state ...")
final_state = make_fluid_state(current_cv, gas_model)
final_dv = final_state.dv
my_write_viz(step=current_step, t=current_t, state=current_cv, dv=final_dv)
my_write_restart(step=current_step, t=current_t, state=current_cv)
if logmgr:
logmgr.close()
elif use_profiling:
print(actx.tabulate_profiling_data())
finish_tol = 1e-16
assert np.abs(current_t - t_final) < finish_tol
def main(ctx_factory, dim=2, order=3, visualize=False):
cl_ctx = ctx_factory()
queue = cl.CommandQueue(cl_ctx)
actx = PyOpenCLArrayContext(
queue,
allocator=cl_tools.MemoryPool(cl_tools.ImmediateAllocator(queue)),
force_device_scalars=True,
)
nel_1d = 16
from meshmode.mesh.generation import generate_regular_rect_mesh
mesh = generate_regular_rect_mesh(
a=(-0.5,)*dim,
b=(0.5,)*dim,
nelements_per_axis=(nel_1d,)*dim)
logger.info("%d elements", mesh.nelements)
from meshmode.discretization.poly_element import \
QuadratureSimplexGroupFactory, \
default_simplex_group_factory
dcoll = DiscretizationCollection(
actx, mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(base_dim=dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(3*order),
}
)
# bounded above by 1
c = 0.2 + 0.8*bump(actx, dcoll, center=np.zeros(3), width=0.5)
dt = 0.5 * estimate_rk4_timestep(actx, dcoll, c=1)
fields = flat_obj_array(
bump(actx, dcoll, ),
[dcoll.zeros(actx) for i in range(dcoll.dim)]
)
vis = make_visualizer(dcoll)
def rhs(t, w):
return wave_operator(dcoll, c=c, w=w)
logger.info("dt = %g", dt)
t = 0
t_final = 3
istep = 0
while t < t_final:
fields = rk4_step(fields, t, dt, rhs)
if istep % 10 == 0:
logger.info(f"step: {istep} t: {t} "
f"L2: {op.norm(dcoll, fields[0], 2)} "
f"Linf: {op.norm(dcoll, fields[0], np.inf)} "
f"sol max: {op.nodal_max(dcoll, 'vol', fields[0])} "
f"sol min: {op.nodal_min(dcoll, 'vol', fields[0])}")
if visualize:
vis.write_vtk_file(
f"fld-wave-eager-var-velocity-{istep:04d}.vtu",
[
("c", c),
("u", fields[0]),
("v", fields[1:]),
]
)
t += dt
istep += 1
# NOTE: These are here to ensure the solution is bounded for the
# time interval specified
assert op.norm(dcoll, fields[0], 2) < 1
def main(ctx_factory=cl.create_some_context,
use_logmgr=True,
use_leap=False,
use_overintegration=False,
use_profiling=False,
casename=None,
rst_filename=None,
actx_class=PyOpenCLArrayContext,
log_dependent=True):
"""Drive example."""
cl_ctx = ctx_factory()
if casename is None:
casename = "mirgecom"
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
nproc = comm.Get_size()
from mirgecom.simutil import global_reduce as _global_reduce
global_reduce = partial(_global_reduce, comm=comm)
logmgr = initialize_logmgr(use_logmgr,
filename=f"{casename}.sqlite",
mode="wu",
mpi_comm=comm)
if use_profiling:
queue = cl.CommandQueue(
cl_ctx, properties=cl.command_queue_properties.PROFILING_ENABLE)
else:
queue = cl.CommandQueue(cl_ctx)
actx = actx_class(queue,
allocator=cl_tools.MemoryPool(
cl_tools.ImmediateAllocator(queue)))
# Some discretization parameters
dim = 2
nel_1d = 8
order = 1
# {{{ Time stepping control
# This example runs only 3 steps by default (to keep CI ~short)
# With the mixture defined below, equilibrium is achieved at ~40ms
# To run to equilibrium, set t_final >= 40ms.
# Time stepper selection
if use_leap:
from leap.rk import RK4MethodBuilder
timestepper = RK4MethodBuilder("state")
else:
timestepper = rk4_step
# Time loop control parameters
current_step = 0
t_final = 1e-8
current_cfl = 1.0
current_dt = 1e-9
current_t = 0
constant_cfl = False
# i.o frequencies
nstatus = 1
nviz = 5
nhealth = 1
nrestart = 5
# }}} Time stepping control
debug = False
rst_path = "restart_data/"
rst_pattern = (rst_path + "{cname}-{step:04d}-{rank:04d}.pkl")
if rst_filename: # read the grid from restart data
rst_filename = f"{rst_filename}-{rank:04d}.pkl"
from mirgecom.restart import read_restart_data
restart_data = read_restart_data(actx, rst_filename)
local_mesh = restart_data["local_mesh"]
local_nelements = local_mesh.nelements
global_nelements = restart_data["global_nelements"]
assert restart_data["num_parts"] == nproc
rst_time = restart_data["t"]
rst_step = restart_data["step"]
rst_order = restart_data["order"]
else: # generate the grid from scratch
from meshmode.mesh.generation import generate_regular_rect_mesh
box_ll = -0.005
box_ur = 0.005
generate_mesh = partial(generate_regular_rect_mesh,
a=(box_ll, ) * dim,
b=(box_ur, ) * dim,
nelements_per_axis=(nel_1d, ) * dim)
local_mesh, global_nelements = generate_and_distribute_mesh(
comm, generate_mesh)
local_nelements = local_mesh.nelements
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
discr = EagerDGDiscretization(
actx,
local_mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE:
default_simplex_group_factory(base_dim=local_mesh.dim,
order=order),
DISCR_TAG_QUAD:
QuadratureSimplexGroupFactory(2 * order + 1)
},
mpi_communicator=comm)
nodes = thaw(discr.nodes(), actx)
ones = discr.zeros(actx) + 1.0
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
ones = discr.zeros(actx) + 1.0
vis_timer = None
if logmgr:
logmgr_add_cl_device_info(logmgr, queue)
logmgr_add_device_memory_usage(logmgr, queue)
vis_timer = IntervalTimer("t_vis", "Time spent visualizing")
logmgr.add_quantity(vis_timer)
logmgr.add_watches([("step.max", "step = {value}, "),
("t_sim.max", "sim time: {value:1.6e} s\n"),
("t_step.max",
"------- step walltime: {value:6g} s, "),
("t_log.max", "log walltime: {value:6g} s")])
if log_dependent:
logmgr_add_many_discretization_quantities(
logmgr, discr, dim, extract_vars_for_logging,
units_for_logging)
logmgr.add_watches([
("min_pressure",
"\n------- P (min, max) (Pa) = ({value:1.9e}, "),
("max_pressure", "{value:1.9e})\n"),
("min_temperature",
"------- T (min, max) (K) = ({value:7g}, "),
("max_temperature", "{value:7g})\n")
])
# {{{ Set up initial state using Cantera
# Use Cantera for initialization
# -- Pick up a CTI for the thermochemistry config
# --- Note: Users may add their own CTI file by dropping it into
# --- mirgecom/mechanisms alongside the other CTI files.
from mirgecom.mechanisms import get_mechanism_cti
mech_cti = get_mechanism_cti("uiuc")
cantera_soln = cantera.Solution(phase_id="gas", source=mech_cti)
nspecies = cantera_soln.n_species
# Initial temperature, pressure, and mixutre mole fractions are needed to
# set up the initial state in Cantera.
temperature_seed = 1500.0 # Initial temperature hot enough to burn
# Parameters for calculating the amounts of fuel, oxidizer, and inert species
equiv_ratio = 1.0
ox_di_ratio = 0.21
stoich_ratio = 3.0
# Grab the array indices for the specific species, ethylene, oxygen, and nitrogen
i_fu = cantera_soln.species_index("C2H4")
i_ox = cantera_soln.species_index("O2")
i_di = cantera_soln.species_index("N2")
x = np.zeros(nspecies)
# Set the species mole fractions according to our desired fuel/air mixture
x[i_fu] = (ox_di_ratio * equiv_ratio) / (stoich_ratio +
ox_di_ratio * equiv_ratio)
x[i_ox] = stoich_ratio * x[i_fu] / equiv_ratio
x[i_di] = (1.0 - ox_di_ratio) * x[i_ox] / ox_di_ratio
# Uncomment next line to make pylint fail when it can't find cantera.one_atm
one_atm = cantera.one_atm # pylint: disable=no-member
# one_atm = 101325.0
# Let the user know about how Cantera is being initilized
print(f"Input state (T,P,X) = ({temperature_seed}, {one_atm}, {x}")
# Set Cantera internal gas temperature, pressure, and mole fractios
cantera_soln.TPX = temperature_seed, one_atm, x
# Pull temperature, total density, mass fractions, and pressure from Cantera
# We need total density, and mass fractions to initialize the fluid/gas state.
can_t, can_rho, can_y = cantera_soln.TDY
can_p = cantera_soln.P
# *can_t*, *can_p* should not differ (significantly) from user's initial data,
# but we want to ensure that we use exactly the same starting point as Cantera,
# so we use Cantera's version of these data.
# }}}
# {{{ Create Pyrometheus thermochemistry object & EOS
# Create a Pyrometheus EOS with the Cantera soln. Pyrometheus uses Cantera and
# generates a set of methods to calculate chemothermomechanical properties and
# states for this particular mechanism.
from mirgecom.thermochemistry import make_pyrometheus_mechanism_class
pyro_mechanism = make_pyrometheus_mechanism_class(cantera_soln)(actx.np)
eos = PyrometheusMixture(pyro_mechanism,
temperature_guess=temperature_seed)
gas_model = GasModel(eos=eos)
from pytools.obj_array import make_obj_array
def get_temperature_update(cv, temperature):
y = cv.species_mass_fractions
e = gas_model.eos.internal_energy(cv) / cv.mass
return pyro_mechanism.get_temperature_update_energy(e, temperature, y)
from mirgecom.gas_model import make_fluid_state
def get_fluid_state(cv, tseed):
return make_fluid_state(cv=cv,
gas_model=gas_model,
temperature_seed=tseed)
compute_temperature_update = actx.compile(get_temperature_update)
construct_fluid_state = actx.compile(get_fluid_state)
# }}}
# {{{ MIRGE-Com state initialization
# Initialize the fluid/gas state with Cantera-consistent data:
# (density, pressure, temperature, mass_fractions)
print(f"Cantera state (rho,T,P,Y) = ({can_rho}, {can_t}, {can_p}, {can_y}")
velocity = np.zeros(shape=(dim, ))
initializer = MixtureInitializer(dim=dim,
nspecies=nspecies,
pressure=can_p,
temperature=can_t,
massfractions=can_y,
velocity=velocity)
my_boundary = AdiabaticSlipBoundary()
boundaries = {BTAG_ALL: my_boundary}
if rst_filename:
current_step = rst_step
current_t = rst_time
if logmgr:
from mirgecom.logging_quantities import logmgr_set_time
logmgr_set_time(logmgr, current_step, current_t)
if order == rst_order:
current_cv = restart_data["cv"]
temperature_seed = restart_data["temperature_seed"]
else:
rst_cv = restart_data["cv"]
old_discr = EagerDGDiscretization(actx,
local_mesh,
order=rst_order,
mpi_communicator=comm)
from meshmode.discretization.connection import make_same_mesh_connection
connection = make_same_mesh_connection(
actx, discr.discr_from_dd("vol"),
old_discr.discr_from_dd("vol"))
current_cv = connection(rst_cv)
temperature_seed = connection(restart_data["temperature_seed"])
else:
# Set the current state from time 0
current_cv = initializer(eos=gas_model.eos, x_vec=nodes)
temperature_seed = temperature_seed * ones
# The temperature_seed going into this function is:
# - At time 0: the initial temperature input data (maybe from Cantera)
# - On restart: the restarted temperature seed from restart file (saving
# the *seed* allows restarts to be deterministic
current_fluid_state = construct_fluid_state(current_cv, temperature_seed)
current_dv = current_fluid_state.dv
temperature_seed = current_dv.temperature
# Inspection at physics debugging time
if debug:
print("Initial MIRGE-Com state:")
print(f"Initial DV pressure: {current_fluid_state.pressure}")
print(f"Initial DV temperature: {current_fluid_state.temperature}")
# }}}
visualizer = make_visualizer(discr)
initname = initializer.__class__.__name__
eosname = gas_model.eos.__class__.__name__
init_message = make_init_message(dim=dim,
order=order,
nelements=local_nelements,
global_nelements=global_nelements,
dt=current_dt,
t_final=t_final,
nstatus=nstatus,
nviz=nviz,
cfl=current_cfl,
constant_cfl=constant_cfl,
initname=initname,
eosname=eosname,
casename=casename)
# Cantera equilibrate calculates the expected end state @ chemical equilibrium
# i.e. the expected state after all reactions
cantera_soln.equilibrate("UV")
eq_temperature, eq_density, eq_mass_fractions = cantera_soln.TDY
eq_pressure = cantera_soln.P
# Report the expected final state to the user
if rank == 0:
logger.info(init_message)
logger.info(f"Expected equilibrium state:"
f" {eq_pressure=}, {eq_temperature=},"
f" {eq_density=}, {eq_mass_fractions=}")
def my_write_status(dt, cfl, dv=None):
status_msg = f"------ {dt=}" if constant_cfl else f"----- {cfl=}"
if ((dv is not None) and (not log_dependent)):
temp = dv.temperature
press = dv.pressure
from grudge.op import nodal_min_loc, nodal_max_loc
tmin = allsync(actx.to_numpy(nodal_min_loc(discr, "vol", temp)),
comm=comm,
op=MPI.MIN)
tmax = allsync(actx.to_numpy(nodal_max_loc(discr, "vol", temp)),
comm=comm,
op=MPI.MAX)
pmin = allsync(actx.to_numpy(nodal_min_loc(discr, "vol", press)),
comm=comm,
op=MPI.MIN)
pmax = allsync(actx.to_numpy(nodal_max_loc(discr, "vol", press)),
comm=comm,
op=MPI.MAX)
dv_status_msg = f"\nP({pmin}, {pmax}), T({tmin}, {tmax})"
status_msg = status_msg + dv_status_msg
if rank == 0:
logger.info(status_msg)
def my_write_viz(step, t, dt, state, ts_field, dv, production_rates, cfl):
viz_fields = [("cv", state), ("dv", dv),
("production_rates", production_rates),
("dt" if constant_cfl else "cfl", ts_field)]
write_visfile(discr,
viz_fields,
visualizer,
vizname=casename,
step=step,
t=t,
overwrite=True,
vis_timer=vis_timer)
def my_write_restart(step, t, state, temperature_seed):
rst_fname = rst_pattern.format(cname=casename, step=step, rank=rank)
if rst_fname == rst_filename:
if rank == 0:
logger.info("Skipping overwrite of restart file.")
else:
rst_data = {
"local_mesh": local_mesh,
"cv": state.cv,
"temperature_seed": temperature_seed,
"t": t,
"step": step,
"order": order,
"global_nelements": global_nelements,
"num_parts": nproc
}
from mirgecom.restart import write_restart_file
write_restart_file(actx, rst_data, rst_fname, comm)
def my_health_check(cv, dv):
import grudge.op as op
health_error = False
pressure = dv.pressure
temperature = dv.temperature
from mirgecom.simutil import check_naninf_local, check_range_local
if check_naninf_local(discr, "vol", pressure):
health_error = True
logger.info(f"{rank=}: Invalid pressure data found.")
if check_range_local(discr, "vol", pressure, 1e5, 2.6e5):
health_error = True
logger.info(f"{rank=}: Pressure range violation.")
if check_naninf_local(discr, "vol", temperature):
health_error = True
logger.info(f"{rank=}: Invalid temperature data found.")
if check_range_local(discr, "vol", temperature, 1.498e3, 1.6e3):
health_error = True
logger.info(f"{rank=}: Temperature range violation.")
# This check is the temperature convergence check
# The current *temperature* is what Pyrometheus gets
# after a fixed number of Newton iterations, *n_iter*.
# Calling `compute_temperature` here with *temperature*
# input as the guess returns the calculated gas temperature after
# yet another *n_iter*.
# The difference between those two temperatures is the
# temperature residual, which can be used as an indicator of
# convergence in Pyrometheus `get_temperature`.
# Note: The local max jig below works around a very long compile
# in lazy mode.
temp_resid = compute_temperature_update(cv, temperature) / temperature
temp_err = (actx.to_numpy(op.nodal_max_loc(discr, "vol", temp_resid)))
if temp_err > 1e-8:
health_error = True
logger.info(
f"{rank=}: Temperature is not converged {temp_resid=}.")
return health_error
from mirgecom.inviscid import get_inviscid_timestep
def get_dt(state):
return get_inviscid_timestep(discr, state=state)
compute_dt = actx.compile(get_dt)
from mirgecom.inviscid import get_inviscid_cfl
def get_cfl(state, dt):
return get_inviscid_cfl(discr, dt=dt, state=state)
compute_cfl = actx.compile(get_cfl)
def get_production_rates(cv, temperature):
return eos.get_production_rates(cv, temperature)
compute_production_rates = actx.compile(get_production_rates)
def my_get_timestep(t, dt, state):
# richer interface to calculate {dt,cfl} returns node-local estimates
t_remaining = max(0, t_final - t)
if constant_cfl:
ts_field = current_cfl * compute_dt(state)
from grudge.op import nodal_min_loc
dt = allsync(actx.to_numpy(nodal_min_loc(discr, "vol", ts_field)),
comm=comm,
op=MPI.MIN)
cfl = current_cfl
else:
ts_field = compute_cfl(state, current_dt)
from grudge.op import nodal_max_loc
cfl = allsync(actx.to_numpy(nodal_max_loc(discr, "vol", ts_field)),
comm=comm,
op=MPI.MAX)
return ts_field, cfl, min(t_remaining, dt)
def my_pre_step(step, t, dt, state):
cv, tseed = state
fluid_state = construct_fluid_state(cv, tseed)
dv = fluid_state.dv
try:
if logmgr:
logmgr.tick_before()
from mirgecom.simutil import check_step
do_viz = check_step(step=step, interval=nviz)
do_restart = check_step(step=step, interval=nrestart)
do_health = check_step(step=step, interval=nhealth)
do_status = check_step(step=step, interval=nstatus)
if do_health:
health_errors = global_reduce(my_health_check(cv, dv),
op="lor")
if health_errors:
if rank == 0:
logger.info("Fluid solution failed health check.")
raise MyRuntimeError("Failed simulation health check.")
ts_field, cfl, dt = my_get_timestep(t=t, dt=dt, state=fluid_state)
if do_status:
my_write_status(dt=dt, cfl=cfl, dv=dv)
if do_restart:
my_write_restart(step=step,
t=t,
state=fluid_state,
temperature_seed=tseed)
if do_viz:
production_rates = compute_production_rates(
fluid_state.cv, fluid_state.temperature)
my_write_viz(step=step,
t=t,
dt=dt,
state=cv,
dv=dv,
production_rates=production_rates,
ts_field=ts_field,
cfl=cfl)
except MyRuntimeError:
if rank == 0:
logger.info("Errors detected; attempting graceful exit.")
# my_write_viz(step=step, t=t, dt=dt, state=cv)
# my_write_restart(step=step, t=t, state=fluid_state)
raise
return state, dt
def my_post_step(step, t, dt, state):
cv, tseed = state
fluid_state = construct_fluid_state(cv, tseed)
# Logmgr needs to know about EOS, dt, dim?
# imo this is a design/scope flaw
if logmgr:
set_dt(logmgr, dt)
set_sim_state(logmgr, dim, cv, gas_model.eos)
logmgr.tick_after()
return make_obj_array([cv, fluid_state.temperature]), dt
def my_rhs(t, state):
cv, tseed = state
from mirgecom.gas_model import make_fluid_state
fluid_state = make_fluid_state(cv=cv,
gas_model=gas_model,
temperature_seed=tseed)
return make_obj_array([
euler_operator(discr,
state=fluid_state,
time=t,
boundaries=boundaries,
gas_model=gas_model,
quadrature_tag=quadrature_tag) +
eos.get_species_source_terms(cv, fluid_state.temperature),
0 * tseed
])
current_dt = get_sim_timestep(discr, current_fluid_state, current_t,
current_dt, current_cfl, t_final,
constant_cfl)
current_step, current_t, current_state = \
advance_state(rhs=my_rhs, timestepper=timestepper,
pre_step_callback=my_pre_step,
post_step_callback=my_post_step, dt=current_dt,
state=make_obj_array([current_cv, temperature_seed]),
t=current_t, t_final=t_final)
# Dump the final data
if rank == 0:
logger.info("Checkpointing final state ...")
final_cv, tseed = current_state
final_fluid_state = construct_fluid_state(final_cv, tseed)
final_dv = final_fluid_state.dv
final_dm = compute_production_rates(final_cv, final_dv.temperature)
ts_field, cfl, dt = my_get_timestep(t=current_t,
dt=current_dt,
state=final_fluid_state)
my_write_viz(step=current_step,
t=current_t,
dt=dt,
state=final_cv,
dv=final_dv,
production_rates=final_dm,
ts_field=ts_field,
cfl=cfl)
my_write_status(dt=dt, cfl=cfl, dv=final_dv)
my_write_restart(step=current_step,
t=current_t,
state=final_fluid_state,
temperature_seed=tseed)
if logmgr:
logmgr.close()
elif use_profiling:
print(actx.tabulate_profiling_data())
finish_tol = 1e-16
assert np.abs(current_t - t_final) < finish_tol
def test_uniform_rhs(actx_factory, nspecies, dim, order, use_overintegration):
"""Test the inviscid rhs using a trivial constant/uniform state.
This state should yield rhs = 0 to FP. The test is performed for 1, 2,
and 3 dimensions, with orders 1, 2, and 3, with and without passive species.
"""
actx = actx_factory()
tolerance = 1e-9
from pytools.convergence import EOCRecorder
eoc_rec0 = EOCRecorder()
eoc_rec1 = EOCRecorder()
# for nel_1d in [4, 8, 12]:
for nel_1d in [4, 8]:
from meshmode.mesh.generation import generate_regular_rect_mesh
mesh = generate_regular_rect_mesh(
a=(-0.5,) * dim, b=(0.5,) * dim, nelements_per_axis=(nel_1d,) * dim
)
logger.info(
f"Number of {dim}d elements: {mesh.nelements}"
)
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
discr = EagerDGDiscretization(
actx, mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(
base_dim=dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
}
)
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
zeros = discr.zeros(actx)
ones = zeros + 1.0
mass_input = discr.zeros(actx) + 1
energy_input = discr.zeros(actx) + 2.5
mom_input = make_obj_array(
[discr.zeros(actx) for i in range(discr.dim)]
)
mass_frac_input = flat_obj_array(
[ones / ((i + 1) * 10) for i in range(nspecies)]
)
species_mass_input = mass_input * mass_frac_input
num_equations = dim + 2 + len(species_mass_input)
cv = make_conserved(
dim, mass=mass_input, energy=energy_input, momentum=mom_input,
species_mass=species_mass_input)
gas_model = GasModel(eos=IdealSingleGas())
fluid_state = make_fluid_state(cv, gas_model)
expected_rhs = make_conserved(
dim, q=make_obj_array([discr.zeros(actx)
for i in range(num_equations)])
)
boundaries = {BTAG_ALL: DummyBoundary()}
inviscid_rhs = euler_operator(discr, state=fluid_state, gas_model=gas_model,
boundaries=boundaries, time=0.0,
quadrature_tag=quadrature_tag)
rhs_resid = inviscid_rhs - expected_rhs
rho_resid = rhs_resid.mass
rhoe_resid = rhs_resid.energy
mom_resid = rhs_resid.momentum
rhoy_resid = rhs_resid.species_mass
rho_rhs = inviscid_rhs.mass
rhoe_rhs = inviscid_rhs.energy
rhov_rhs = inviscid_rhs.momentum
rhoy_rhs = inviscid_rhs.species_mass
logger.info(
f"rho_rhs = {rho_rhs}\n"
f"rhoe_rhs = {rhoe_rhs}\n"
f"rhov_rhs = {rhov_rhs}\n"
f"rhoy_rhs = {rhoy_rhs}\n"
)
def inf_norm(x):
return actx.to_numpy(discr.norm(x, np.inf))
assert inf_norm(rho_resid) < tolerance
assert inf_norm(rhoe_resid) < tolerance
for i in range(dim):
assert inf_norm(mom_resid[i]) < tolerance
for i in range(nspecies):
assert inf_norm(rhoy_resid[i]) < tolerance
err_max = inf_norm(rho_resid)
eoc_rec0.add_data_point(1.0 / nel_1d, err_max)
# set a non-zero, but uniform velocity component
for i in range(len(mom_input)):
mom_input[i] = discr.zeros(actx) + (-1.0) ** i
cv = make_conserved(
dim, mass=mass_input, energy=energy_input, momentum=mom_input,
species_mass=species_mass_input)
gas_model = GasModel(eos=IdealSingleGas())
fluid_state = make_fluid_state(cv, gas_model)
boundaries = {BTAG_ALL: DummyBoundary()}
inviscid_rhs = euler_operator(discr, state=fluid_state, gas_model=gas_model,
boundaries=boundaries, time=0.0)
rhs_resid = inviscid_rhs - expected_rhs
rho_resid = rhs_resid.mass
rhoe_resid = rhs_resid.energy
mom_resid = rhs_resid.momentum
rhoy_resid = rhs_resid.species_mass
assert inf_norm(rho_resid) < tolerance
assert inf_norm(rhoe_resid) < tolerance
for i in range(dim):
assert inf_norm(mom_resid[i]) < tolerance
for i in range(nspecies):
assert inf_norm(rhoy_resid[i]) < tolerance
err_max = inf_norm(rho_resid)
eoc_rec1.add_data_point(1.0 / nel_1d, err_max)
logger.info(
f"V == 0 Errors:\n{eoc_rec0}"
f"V != 0 Errors:\n{eoc_rec1}"
)
assert (
eoc_rec0.order_estimate() >= order - 0.5
or eoc_rec0.max_error() < 1e-9
)
assert (
eoc_rec1.order_estimate() >= order - 0.5
or eoc_rec1.max_error() < 1e-9
)
def _euler_flow_stepper(actx, parameters):
logging.basicConfig(format="%(message)s", level=logging.INFO)
mesh = parameters["mesh"]
t = parameters["time"]
order = parameters["order"]
t_final = parameters["tfinal"]
initializer = parameters["initializer"]
exittol = parameters["exittol"]
casename = parameters["casename"]
boundaries = parameters["boundaries"]
eos = parameters["eos"]
cfl = parameters["cfl"]
dt = parameters["dt"]
constantcfl = parameters["constantcfl"]
nstepstatus = parameters["nstatus"]
use_overintegration = parameters["use_overintegration"]
if t_final <= t:
return(0.0)
rank = 0
dim = mesh.dim
istep = 0
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
discr = EagerDGDiscretization(
actx, mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(
base_dim=dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
}
)
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
nodes = thaw(discr.nodes(), actx)
cv = initializer(nodes)
gas_model = GasModel(eos=eos)
fluid_state = make_fluid_state(cv, gas_model)
sdt = cfl * get_inviscid_timestep(discr, fluid_state)
initname = initializer.__class__.__name__
eosname = eos.__class__.__name__
logger.info(
f"Num {dim}d order-{order} elements: {mesh.nelements}\n"
f"Timestep: {dt}\n"
f"Final time: {t_final}\n"
f"Status freq: {nstepstatus}\n"
f"Initialization: {initname}\n"
f"EOS: {eosname}"
)
vis = make_visualizer(discr, order)
def write_soln(state, write_status=True):
dv = eos.dependent_vars(cv=state)
expected_result = initializer(nodes, t=t)
result_resid = state - expected_result
maxerr = [np.max(np.abs(result_resid[i].get())) for i in range(dim + 2)]
mindv = [np.min(dvfld.get()) for dvfld in dv]
maxdv = [np.max(dvfld.get()) for dvfld in dv]
if write_status is True:
statusmsg = (
f"Status: Step({istep}) Time({t})\n"
f"------ P({mindv[0]},{maxdv[0]})\n"
f"------ T({mindv[1]},{maxdv[1]})\n"
f"------ dt,cfl = ({dt},{cfl})\n"
f"------ Err({maxerr})"
)
logger.info(statusmsg)
io_fields = ["cv", state]
io_fields += eos.split_fields(dim, dv)
io_fields.append(("exact_soln", expected_result))
io_fields.append(("residual", result_resid))
nameform = casename + "-{iorank:04d}-{iostep:06d}.vtu"
visfilename = nameform.format(iorank=rank, iostep=istep)
vis.write_vtk_file(visfilename, io_fields)
return maxerr
def rhs(t, q):
fluid_state = make_fluid_state(q, gas_model)
return euler_operator(discr, fluid_state, boundaries=boundaries,
gas_model=gas_model, time=t,
quadrature_tag=quadrature_tag)
filter_order = 8
eta = .5
alpha = -1.0*np.log(np.finfo(float).eps)
nummodes = int(1)
for _ in range(dim):
nummodes *= int(order + dim + 1)
nummodes /= math.factorial(int(dim))
cutoff = int(eta * order)
from mirgecom.filter import (
exponential_mode_response_function as xmrfunc,
filter_modally
)
frfunc = partial(xmrfunc, alpha=alpha, filter_order=filter_order)
while t < t_final:
if constantcfl is True:
dt = sdt
else:
cfl = dt / sdt
if nstepstatus > 0:
if istep % nstepstatus == 0:
write_soln(state=cv)
cv = rk4_step(cv, t, dt, rhs)
cv = filter_modally(discr, "vol", cutoff, frfunc, cv)
t += dt
istep += 1
sdt = cfl * get_inviscid_timestep(discr, fluid_state)
if nstepstatus > 0:
logger.info("Writing final dump.")
maxerr = max(write_soln(cv, False))
else:
expected_result = initializer(nodes, time=t)
maxerr = max_component_norm(discr, cv-expected_result, np.inf)
logger.info(f"Max Error: {maxerr}")
if maxerr > exittol:
raise ValueError("Solution failed to follow expected result.")
return(maxerr)
def test_multilump_rhs(actx_factory, dim, order, v0, use_overintegration):
"""Test the Euler rhs using the non-trivial 1, 2, and 3D mass lump case.
The case is tested against the analytic expressions of the RHS. Checks several
different orders and refinement levels to check error behavior.
"""
actx = actx_factory()
nspecies = 10
tolerance = 1e-8
maxxerr = 0.0
from pytools.convergence import EOCRecorder
eoc_rec = EOCRecorder()
for nel_1d in [4, 8, 12]:
from meshmode.mesh.generation import (
generate_regular_rect_mesh,
)
mesh = generate_regular_rect_mesh(
a=(-1,) * dim, b=(1,) * dim, nelements_per_axis=(nel_1d,) * dim,
)
logger.info(f"Number of elements: {mesh.nelements}")
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
discr = EagerDGDiscretization(
actx, mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(
base_dim=dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
}
)
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
nodes = thaw(discr.nodes(), actx)
centers = make_obj_array([np.zeros(shape=(dim,)) for i in range(nspecies)])
spec_y0s = np.ones(shape=(nspecies,))
spec_amplitudes = np.ones(shape=(nspecies,))
velocity = np.zeros(shape=(dim,))
velocity[0] = v0
rho0 = 2.0
lump = MulticomponentLump(dim=dim, nspecies=nspecies, rho0=rho0,
spec_centers=centers, velocity=velocity,
spec_y0s=spec_y0s, spec_amplitudes=spec_amplitudes)
lump_soln = lump(nodes)
gas_model = GasModel(eos=IdealSingleGas())
fluid_state = make_fluid_state(lump_soln, gas_model)
def _my_boundary(discr, btag, gas_model, state_minus, **kwargs):
actx = state_minus.array_context
bnd_discr = discr.discr_from_dd(btag)
nodes = thaw(bnd_discr.nodes(), actx)
return make_fluid_state(lump(x_vec=nodes, **kwargs), gas_model)
boundaries = {
BTAG_ALL: PrescribedFluidBoundary(boundary_state_func=_my_boundary)
}
inviscid_rhs = euler_operator(
discr, state=fluid_state, gas_model=gas_model, boundaries=boundaries,
time=0.0, quadrature_tag=quadrature_tag
)
expected_rhs = lump.exact_rhs(discr, cv=lump_soln, time=0)
print(f"inviscid_rhs = {inviscid_rhs}")
print(f"expected_rhs = {expected_rhs}")
err_max = actx.to_numpy(
discr.norm((inviscid_rhs-expected_rhs), np.inf))
if err_max > maxxerr:
maxxerr = err_max
eoc_rec.add_data_point(1.0 / nel_1d, err_max)
logger.info(f"Max error: {maxxerr}")
logger.info(
f"Error for (dim,order) = ({dim},{order}):\n"
f"{eoc_rec}"
)
assert (
eoc_rec.order_estimate() >= order - 0.5
or eoc_rec.max_error() < tolerance
)
def test_vortex_rhs(actx_factory, order, use_overintegration):
"""Test the inviscid rhs using the non-trivial 2D isentropic vortex.
The case is configured to yield rhs = 0. Checks several different orders
and refinement levels to check error behavior.
"""
actx = actx_factory()
dim = 2
from pytools.convergence import EOCRecorder
eoc_rec = EOCRecorder()
from meshmode.mesh.generation import generate_regular_rect_mesh
for nel_1d in [32, 48, 64]:
mesh = generate_regular_rect_mesh(
a=(-5,) * dim, b=(5,) * dim, nelements_per_axis=(nel_1d,) * dim,
)
logger.info(
f"Number of {dim}d elements: {mesh.nelements}"
)
from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
from meshmode.discretization.poly_element import \
default_simplex_group_factory, QuadratureSimplexGroupFactory
discr = EagerDGDiscretization(
actx, mesh,
discr_tag_to_group_factory={
DISCR_TAG_BASE: default_simplex_group_factory(
base_dim=dim, order=order),
DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
}
)
if use_overintegration:
quadrature_tag = DISCR_TAG_QUAD
else:
quadrature_tag = None
nodes = thaw(discr.nodes(), actx)
# Init soln with Vortex and expected RHS = 0
vortex = Vortex2D(center=[0, 0], velocity=[0, 0])
vortex_soln = vortex(nodes)
gas_model = GasModel(eos=IdealSingleGas())
fluid_state = make_fluid_state(vortex_soln, gas_model)
def _vortex_boundary(discr, btag, gas_model, state_minus, **kwargs):
actx = state_minus.array_context
bnd_discr = discr.discr_from_dd(btag)
nodes = thaw(bnd_discr.nodes(), actx)
return make_fluid_state(vortex(x_vec=nodes, **kwargs), gas_model)
boundaries = {
BTAG_ALL: PrescribedFluidBoundary(boundary_state_func=_vortex_boundary)
}
inviscid_rhs = euler_operator(
discr, state=fluid_state, gas_model=gas_model, boundaries=boundaries,
time=0.0, quadrature_tag=quadrature_tag)
err_max = max_component_norm(discr, inviscid_rhs, np.inf)
eoc_rec.add_data_point(1.0 / nel_1d, err_max)
logger.info(
f"Error for (dim,order) = ({dim},{order}):\n"
f"{eoc_rec}"
)
assert (
eoc_rec.order_estimate() >= order - 0.5
or eoc_rec.max_error() < 1e-11
)
def main(ctx_factory, dim=2, order=4, use_quad=False, visualize=False):
cl_ctx = ctx_factory()
queue = cl.CommandQueue(cl_ctx)
actx = PyOpenCLArrayContext(
queue,
allocator=cl_tools.MemoryPool(cl_tools.ImmediateAllocator(queue)),
force_device_scalars=True,
)
# {{{ parameters
# sphere radius
radius = 1.0
# sphere resolution
resolution = 64 if dim == 2 else 1
# final time
final_time = np.pi
# flux
flux_type = "lf"
# }}}
# {{{ discretization
if dim == 2:
from meshmode.mesh.generation import make_curve_mesh, ellipse
mesh = make_curve_mesh(
lambda t: radius * ellipse(1.0, t),
np.linspace(0.0, 1.0, resolution + 1),
order)
elif dim == 3:
from meshmode.mesh.generation import generate_icosphere
mesh = generate_icosphere(radius, order=4 * order,
uniform_refinement_rounds=resolution)
else:
raise ValueError("unsupported dimension")
discr_tag_to_group_factory = {}
if use_quad:
qtag = dof_desc.DISCR_TAG_QUAD
else:
qtag = None
from meshmode.discretization.poly_element import \
default_simplex_group_factory, \
QuadratureSimplexGroupFactory
discr_tag_to_group_factory[dof_desc.DISCR_TAG_BASE] = \
default_simplex_group_factory(base_dim=dim-1, order=order)
if use_quad:
discr_tag_to_group_factory[qtag] = \
QuadratureSimplexGroupFactory(order=4*order)
from grudge import DiscretizationCollection
dcoll = DiscretizationCollection(
actx, mesh,
discr_tag_to_group_factory=discr_tag_to_group_factory
)
volume_discr = dcoll.discr_from_dd(dof_desc.DD_VOLUME)
logger.info("ndofs: %d", volume_discr.ndofs)
logger.info("nelements: %d", volume_discr.mesh.nelements)
# }}}
# {{{ Surface advection operator
# velocity field
x = thaw(dcoll.nodes(), actx)
c = make_obj_array([-x[1], x[0], 0.0])[:dim]
def f_initial_condition(x):
return x[0]
from grudge.models.advection import SurfaceAdvectionOperator
adv_operator = SurfaceAdvectionOperator(
dcoll,
c,
flux_type=flux_type,
quad_tag=qtag
)
u0 = f_initial_condition(x)
def rhs(t, u):
return adv_operator.operator(t, u)
# check velocity is tangential
from grudge.geometry import normal
surf_normal = normal(actx, dcoll, dd=dof_desc.DD_VOLUME)
error = op.norm(dcoll, c.dot(surf_normal), 2)
logger.info("u_dot_n: %.5e", error)
# }}}
# {{{ time stepping
# FIXME: dt estimate is not necessarily valid for surfaces
dt = actx.to_numpy(
0.45 * adv_operator.estimate_rk4_timestep(actx, dcoll, fields=u0))
nsteps = int(final_time // dt) + 1
logger.info("dt: %.5e", dt)
logger.info("nsteps: %d", nsteps)
from grudge.shortcuts import set_up_rk4
dt_stepper = set_up_rk4("u", dt, u0, rhs)
plot = Plotter(actx, dcoll, order, visualize=visualize)
norm_u = actx.to_numpy(op.norm(dcoll, u0, 2))
step = 0
event = dt_stepper.StateComputed(0.0, 0, 0, u0)
plot(event, "fld-surface-%04d" % 0)
if visualize and dim == 3:
from grudge.shortcuts import make_visualizer
vis = make_visualizer(dcoll)
vis.write_vtk_file(
"fld-surface-velocity.vtu",
[
("u", c),
("n", surf_normal)
],
overwrite=True
)
df = dof_desc.DOFDesc(FACE_RESTR_INTERIOR)
face_discr = dcoll.discr_from_dd(df)
face_normal = thaw(dcoll.normal(dd=df), actx)
from meshmode.discretization.visualization import make_visualizer
vis = make_visualizer(actx, face_discr)
vis.write_vtk_file("fld-surface-face-normals.vtu", [
("n", face_normal)
], overwrite=True)
for event in dt_stepper.run(t_end=final_time, max_steps=nsteps + 1):
if not isinstance(event, dt_stepper.StateComputed):
continue
step += 1
if step % 10 == 0:
norm_u = actx.to_numpy(op.norm(dcoll, event.state_component, 2))
plot(event, "fld-surface-%04d" % step)
logger.info("[%04d] t = %.5f |u| = %.5e", step, event.t, norm_u)
# NOTE: These are here to ensure the solution is bounded for the
# time interval specified
assert norm_u < 3
