def get_equations(self):
from pysph.sph.equation import Group
from pysph.sph.wc.basic import TaitEOS
from pysph.sph.basic_equations import XSPHCorrection
from pysph.sph.wc.transport_velocity import (
ContinuityEquation, MomentumEquationPressureGradient,
MomentumEquationViscosity, MomentumEquationArtificialViscosity,
SolidWallPressureBC, SolidWallNoSlipBC, SetWallVelocity,
VolumeSummation)
equations = []
all = self.fluids + self.solids
g2 = []
for fluid in self.fluids:
g2.append(VolumeSummation(dest=fluid, sources=all))
g2.append(
TaitEOS(dest=fluid,
sources=None,
rho0=self.rho0,
c0=self.c0,
gamma=self.gamma,
p0=self.p0))
for solid in self.solids:
g2.append(VolumeSummation(dest=solid, sources=all))
g2.append(SetWallVelocity(dest=solid, sources=self.fluids))
equations.append(Group(equations=g2, real=False))
g3 = []
for solid in self.solids:
g3.append(
SolidWallPressureBC(dest=solid,
sources=self.fluids,
b=1.0,
rho0=self.rho0,
p0=self.B,
gx=self.gx,
gy=self.gy,
gz=self.gz))
equations.append(Group(equations=g3, real=False))
g4 = []
for fluid in self.fluids:
g4.append(ContinuityEquation(dest=fluid, sources=all))
g4.append(
MomentumEquationPressureGradient(dest=fluid,
sources=all,
pb=0.0,
gx=self.gx,
gy=self.gy,
gz=self.gz,
tdamp=self.tdamp))
if self.alpha > 0.0:
g4.append(
MomentumEquationArtificialViscosity(dest=fluid,
sources=all,
c0=self.c0,
alpha=self.alpha))
if self.nu > 0.0:
g4.append(
MomentumEquationViscosity(dest=fluid,
sources=self.fluids,
nu=self.nu))
if len(self.solids) > 0:
g4.append(
SolidWallNoSlipBC(dest=fluid,
sources=self.solids,
nu=self.nu))
g4.append(XSPHCorrection(dest=fluid, sources=[fluid]))
equations.append(Group(equations=g4))
return equations
def get_equations(self):
from pysph.sph.wc.transport_velocity import (
StateEquation, SetWallVelocity, SolidWallPressureBC,
VolumeSummation, SolidWallNoSlipBC,
MomentumEquationArtificialViscosity, ContinuitySolid)
all = self.fluids + self.solids
stage1 = []
if self.solids:
eq0 = []
for solid in self.solids:
eq0.append(SetWallVelocity(dest=solid, sources=self.fluids))
stage1.append(Group(equations=eq0, real=False))
eq1 = []
for fluid in self.fluids:
eq1.append(ContinuityEquationGTVF(dest=fluid, sources=self.fluids))
if self.solids:
eq1.append(ContinuitySolid(dest=fluid, sources=self.solids))
stage1.append(Group(equations=eq1, real=False))
eq2, stage2 = [], []
for fluid in self.fluids:
eq2.append(CorrectDensity(dest=fluid, sources=all))
stage2.append(Group(equations=eq2, real=False))
eq3 = []
for fluid in self.fluids:
eq3.append(
StateEquation(dest=fluid,
sources=None,
p0=self.pref,
rho0=self.rho0,
b=1.0))
stage2.append(Group(equations=eq3, real=False))
g2_s = []
for solid in self.solids:
g2_s.append(VolumeSummation(dest=solid, sources=all))
g2_s.append(
SolidWallPressureBC(dest=solid,
sources=self.fluids,
b=1.0,
rho0=self.rho0,
p0=self.pref,
gx=self.gx,
gy=self.gy,
gz=self.gz))
if g2_s:
stage2.append(Group(equations=g2_s, real=False))
eq4 = []
for fluid in self.fluids:
eq4.append(
MomentumEquationPressureGradient(dest=fluid,
sources=all,
pref=self.pref,
gx=self.gx,
gy=self.gy,
gz=self.gz))
if self.alpha > 0.0:
eq4.append(
MomentumEquationArtificialViscosity(dest=fluid,
sources=all,
c0=self.c0,
alpha=self.alpha))
if self.nu > 0.0:
eq4.append(
MomentumEquationViscosity(dest=fluid,
sources=all,
nu=self.nu))
if self.solids:
eq4.append(
SolidWallNoSlipBC(dest=fluid,
sources=self.solids,
nu=self.nu))
eq4.append(
MomentumEquationArtificialStress(dest=fluid,
sources=self.fluids,
dim=self.dim))
stage2.append(Group(equations=eq4, real=True))
return MultiStageEquations([stage1, stage2])
def get_equations(self):
from pysph.sph.equation import Group
from pysph.sph.wc.transport_velocity import (
SummationDensity, StateEquation, MomentumEquationPressureGradient,
MomentumEquationArtificialViscosity, MomentumEquationViscosity,
MomentumEquationArtificialStress, SolidWallPressureBC,
SolidWallNoSlipBC, SetWallVelocity)
equations = []
all = self.fluids + self.solids
g1 = []
for fluid in self.fluids:
g1.append(SummationDensity(dest=fluid, sources=all))
equations.append(Group(equations=g1, real=False))
g2 = []
for fluid in self.fluids:
g2.append(
StateEquation(dest=fluid,
sources=None,
p0=self.p0,
rho0=self.rho0,
b=1.0))
for solid in self.solids:
g2.append(SetWallVelocity(dest=solid, sources=self.fluids))
equations.append(Group(equations=g2, real=False))
g3 = []
for solid in self.solids:
g3.append(
SolidWallPressureBC(dest=solid,
sources=self.fluids,
b=1.0,
rho0=self.rho0,
p0=self.p0,
gx=self.gx,
gy=self.gy,
gz=self.gz))
equations.append(Group(equations=g3, real=False))
g4 = []
for fluid in self.fluids:
g4.append(
MomentumEquationPressureGradient(dest=fluid,
sources=all,
pb=self.pb,
gx=self.gx,
gy=self.gy,
gz=self.gz,
tdamp=self.tdamp))
if self.alpha > 0.0:
g4.append(
MomentumEquationArtificialViscosity(dest=fluid,
sources=all,
c0=self.c0,
alpha=self.alpha))
if self.nu > 0.0:
g4.append(
MomentumEquationViscosity(dest=fluid,
sources=self.fluids,
nu=self.nu))
if len(self.solids) > 0:
g4.append(
SolidWallNoSlipBC(dest=fluid,
sources=self.solids,
nu=self.nu))
g4.append(
MomentumEquationArtificialStress(dest=fluid,
sources=self.fluids))
equations.append(Group(equations=g4))
return equations
def create_equations(self):
# Formulation for REF1
# (using only first set of equations for simplicity)
equations = [
Group(equations=[
DiffuseMaterial(dest='fluid',
sources=['fluid'],
diffusion_speed=0.1)
], ),
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density
Group(
equations=[VolumeFromMassDensity(dest='fluid',
sources=None)], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
], ),
# The boundary conditions are imposed by extrapolating the fluid
# pressure, taking into consideration the boundary acceleration
Group(equations=[
SolidWallPressureBC(dest='solid',
sources=['fluid'],
b=1.0,
gy=gravity_y,
rho0=rho0,
p0=p0)
], ),
# Main acceleration block
Group(equations=[
# Continuity equation
ContinuityEquation(dest='fluid', sources=['fluid', 'solid']),
# Pressure gradient with acceleration damping
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid', 'solid'],
pb=0.0,
gy=gravity_y,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(dest='fluid',
sources=['fluid', 'solid'],
alpha=0.24,
c0=c0),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid'], eps=0.0)
]),
]
return equations
def _get_external_flow_equations(self):
from pysph.sph.basic_equations import XSPHCorrection
from pysph.sph.wc.transport_velocity import (
VolumeSummation, SolidWallNoSlipBC, SummationDensity,
MomentumEquationArtificialViscosity, MomentumEquationViscosity)
all = self.fluids + self.solids
edac_nu = self._get_edac_nu()
equations = []
group1 = []
for fluid in self.fluids:
group1.append(SummationDensity(dest=fluid, sources=all))
for solid in self.solids:
group1.extend([
VolumeSummation(dest=solid, sources=all),
SolidWallPressureBC(dest=solid,
sources=self.fluids,
gx=self.gx,
gy=self.gy,
gz=self.gz),
SetWallVelocity(dest=solid, sources=self.fluids),
])
if self.clamp_p:
group1.append(ClampWallPressure(dest=solid, sources=None))
equations.append(Group(equations=group1, real=False))
group2 = []
for fluid in self.fluids:
group2.append(
MomentumEquation(dest=fluid,
sources=all,
gx=self.gx,
gy=self.gy,
gz=self.gz,
c0=self.c0,
tdamp=self.tdamp))
if self.alpha > 0.0:
group2.append(
MomentumEquationArtificialViscosity(dest=fluid,
sources=all,
alpha=self.alpha,
c0=self.c0))
if self.nu > 0.0:
group2.append(
MomentumEquationViscosity(dest=fluid,
sources=self.fluids,
nu=self.nu))
if len(self.solids) > 0 and self.nu > 0.0:
group2.append(
SolidWallNoSlipBC(dest=fluid,
sources=self.solids,
nu=self.nu))
group2.extend([
EDACEquation(dest=fluid,
sources=all,
nu=edac_nu,
cs=self.c0,
rho0=self.rho0),
XSPHCorrection(dest=fluid, sources=[fluid], eps=self.eps)
])
equations.append(Group(equations=group2))
return equations
def _get_internal_flow_equations(self):
from pysph.sph.wc.transport_velocity import (
VolumeSummation, SolidWallNoSlipBC, SummationDensity,
MomentumEquationArtificialStress,
MomentumEquationArtificialViscosity, MomentumEquationViscosity)
edac_nu = self._get_edac_nu()
all = self.fluids + self.solids
equations = []
group1 = []
avg_p_group = []
has_solids = len(self.solids) > 0
for fluid in self.fluids:
group1.append(SummationDensity(dest=fluid, sources=all))
if self.bql:
eq = ComputeAveragePressure(dest=fluid, sources=all)
if has_solids:
avg_p_group.append(eq)
else:
group1.append(eq)
for solid in self.solids:
group1.extend([
VolumeSummation(dest=solid, sources=all),
SolidWallPressureBC(dest=solid,
sources=self.fluids,
gx=self.gx,
gy=self.gy,
gz=self.gz),
SetWallVelocity(dest=solid, sources=self.fluids),
])
equations.append(Group(equations=group1, real=False))
# Compute average pressure *after* the wall pressure is setup.
if self.bql and has_solids:
equations.append(Group(equations=avg_p_group, real=True))
group2 = []
for fluid in self.fluids:
group2.append(
MomentumEquationPressureGradient(dest=fluid,
sources=all,
pb=self.pb,
gx=self.gx,
gy=self.gy,
gz=self.gz,
tdamp=self.tdamp))
if self.alpha > 0.0:
group2.append(
MomentumEquationArtificialViscosity(dest=fluid,
sources=all,
alpha=self.alpha,
c0=self.c0))
if self.nu > 0.0:
group2.append(
MomentumEquationViscosity(dest=fluid,
sources=self.fluids,
nu=self.nu))
if len(self.solids) > 0 and self.nu > 0.0:
group2.append(
SolidWallNoSlipBC(dest=fluid,
sources=self.solids,
nu=self.nu))
group2.extend([
MomentumEquationArtificialStress(dest=fluid,
sources=self.fluids),
EDACEquation(dest=fluid,
sources=all,
nu=edac_nu,
cs=self.c0,
rho0=self.rho0),
])
equations.append(Group(equations=group2))
return equations
def create_equations(self):
# Formulation for REF1
equations1 = [
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density.
Group(equations=[
VolumeFromMassDensity(dest='fluid', sources=None)
], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma
Group(equations=[
TaitEOS(dest='fluid', sources=None, rho0=rho0, c0=c0, gamma=gamma),
], ),
# The boundary conditions are imposed by extrapolating the fluid
# pressure, taking into considering the bounday acceleration
Group(equations=[
SolidWallPressureBC(dest='solid', sources=['fluid'], b=1.0, gy=gy,
rho0=rho0, p0=p0),
], ),
# Main acceleration block
Group(equations=[
# Continuity equation
ContinuityEquation(dest='fluid', sources=['fluid','solid']),
# Pressure gradient with acceleration damping.
MomentumEquationPressureGradient(
dest='fluid', sources=['fluid', 'solid'], pb=0.0, gy=gy,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(
dest='fluid', sources=['fluid', 'solid'], alpha=0.24, c0=c0),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid'], eps=0.0)
]),
]
# Formulation for REF2. Note that for this formulation to work, the
# boundary particles need to have a spacing different from the fluid
# particles (usually determined by a factor beta). In the current
# implementation, the value is taken as 1.0 which will mostly be
# ineffective.
equations2 = [
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density.
Group(equations=[
VolumeFromMassDensity(dest='fluid', sources=None)
], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma
Group(equations=[
TaitEOS(dest='fluid', sources=None, rho0=rho0, c0=c0, gamma=gamma),
], ),
# Main acceleration block
Group(equations=[
# The boundary conditions are imposed as a force or
# accelerations on the fluid particles. Note that the
# no-penetration condition is to be satisfied with this
# equation. The subsequent equations therefore do not have
# solid as the source. Note the difference between the
# ghost-fluid formulations. K should be 0.01*co**2
# according to REF2. We take it much smaller here on
# account of the multiple layers of boundary particles
MonaghanKajtarBoundaryForce(dest='fluid', sources=['solid'],
K=0.02, beta=1.0, h=hdx*dx),
# Continuity equation
ContinuityEquation(dest='fluid', sources=['fluid',]),
# Pressure gradient with acceleration damping.
MomentumEquationPressureGradient(
dest='fluid', sources=['fluid'], pb=0.0, gy=gy,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(
dest='fluid', sources=['fluid'], alpha=0.25, c0=c0),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid'], eps=0.0)
]),
]
# Formulation for REF3
equations3 = [
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density.
Group(equations=[
VolumeFromMassDensity(dest='fluid', sources=None)
], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma. The solid phase is treated just as a fluid and
# the pressure and density operations is updated for this as well.
Group(equations=[
TaitEOS(dest='fluid', sources=None, rho0=rho0, c0=c0, gamma=gamma),
TaitEOS(dest='solid', sources=None, rho0=rho0, c0=c0, gamma=gamma),
], ),
# Main acceleration block. The boundary conditions are imposed by
# peforming the continuity equation and gradient of pressure
# calculation on the solid phase, taking contributions from the
# fluid phase
Group(equations=[
# Continuity equation
ContinuityEquation(dest='fluid', sources=['fluid','solid']),
ContinuityEquation(dest='solid', sources=['fluid']),
# Pressure gradient with acceleration damping.
MomentumEquationPressureGradient(
dest='fluid', sources=['fluid', 'solid'], pb=0.0, gy=gy,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(
dest='fluid', sources=['fluid', 'solid'], alpha=0.25, c0=c0),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid'], eps=0.5)
]),
]
if self.options.bc_type == 1:
return equations1
elif self.options.bc_type == 2:
return equations2
elif self.options.bc_type == 3:
return equations3
def create_equations(self):
# Formulation for REF1
equations1 = [
Group(equations=[
HarmonicOscilllator(dest='spoon', sources=None, A=3, omega=0.5),
# Translate acceleration to positions
XSPHCorrection(dest='spoon', sources=['spoon'], eps=0.0)
], real=False),
# Water Faucet Equations
Group(equations=[
H2OFaucet(dest='tahini', sources=None, x=0.5, y=tahiniH, z=1, r=0.1, fill_rate=8),
DiffuseH2O(dest='tahini', sources=['tahini'], diffusion_speed=0.025),
]),
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density.
Group(equations=[
VolumeFromMassDensity(dest='tahini', sources=None)
], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma
Group(equations=[
TaitEOSHGCorrection(
dest='tahini',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
], ),
# The boundary conditions are imposed by extrapolating the tahini
# pressure, taking into considering the bounday acceleration
Group(equations=[
SolidWallPressureBC(dest='bowl', sources=['tahini'], b=1.0, gy=gy,
rho0=rho0, p0=p0),
SolidWallPressureBC(dest='spoon', sources=['tahini'], b=1.0, gy=gy,
rho0=rho0, p0=p0),
], ),
# Main acceleration block
Group(equations=[
TahiniEquation(dest='tahini', sources=['tahini'], sigma=dx / 1.122),
# Continuity equation
ContinuityEquation(
dest='tahini', sources=[
'tahini', 'bowl', 'spoon']),
# Pressure gradient with acceleration damping.
MomentumEquationPressureGradient(
dest='tahini', sources=['tahini', 'bowl', 'spoon'], pb=0.0, gy=gy,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(
dest='tahini', sources=['tahini', 'bowl', 'spoon'], alpha=1, c0=c0),
# Position step with XSPH
XSPHCorrection(dest='tahini', sources=['tahini'], eps=0.0)
]),
]
# Formulation for REF3
equations3 = [
# Spoon Equations
Group(equations=[
HarmonicOscilllator(dest='spoon', sources=None, A=3, omega=0.333),
# Translate acceleration to positions
XSPHCorrection(dest='spoon', sources=['spoon'], eps=0.0)
], real=False),
# Water Faucet Equations
Group(equations=[
H2OFaucet(dest='tahini', sources=None, x=0.5, y=tahiniH, z=1, r=0.1, fill_rate=25),
DiffuseH2O(dest='tahini', sources=['tahini'], diffusion_speed=0.025),
]),
# For the multi-phase formulation, we require an estimate of the
# particle volume. This can be either defined from the particle
# number density or simply as the ratio of mass to density.
Group(equations=[
VolumeFromMassDensity(dest='tahini', sources=None)
], ),
# Equation of state is typically the Tait EOS with a suitable
# exponent gamma. The solid phase is treated just as a fluid and
# the pressure and density operations is updated for this as well.
Group(equations=[
TaitEOS(
dest='tahini',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
TaitEOS(
dest='bowl',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
TaitEOS(
dest='spoon',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
], ),
# Main acceleration block. The boundary conditions are imposed by
# peforming the continuity equation and gradient of pressure
# calculation on the bowl phase, taking contributions from the
# tahini phase
Group(equations=[
TahiniEquation(dest='tahini', sources=['tahini'], sigma=dx / 1.122),
# Continuity equation
ContinuityEquation(
dest='tahini', sources=[
'tahini', 'bowl', 'spoon']),
ContinuityEquation(dest='bowl', sources=['tahini']),
ContinuityEquation(dest='spoon', sources=['tahini']),
# Pressure gradient with acceleration damping.
MomentumEquationPressureGradient(
dest='tahini', sources=['tahini', 'bowl', 'spoon'], pb=0.0, gy=gy,
tdamp=tdamp),
# artificial viscosity for stability
MomentumEquationArtificialViscosity(
dest='tahini', sources=['tahini', 'bowl', 'spoon'], alpha=1, c0=c0),
# Position step with XSPH
XSPHCorrection(dest='tahini', sources=['tahini'], eps=0.5)
]),
]
if self.options.bc_type == 1:
return equations1
elif self.options.bc_type == 3:
return equations3