def create_equations(self):
"""Set up equations.
Body force is necessary to reset fx,fy,fz, although
not body force is applied.
"""
equations = [
Group(equations=[
BodyForce(dest='ellipsoid', sources=None),
NumberDensity(dest='ellipsoid', sources=['ellipsoid']),
NumberDensity(dest='walls', sources=['walls'])
]),
# Tait equation of state
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=self.rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='ellipsoid',
sources=None,
rho0=self.rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='walls',
sources=None,
rho0=self.rho,
c0=self.co,
gamma=7.0),
],
real=False),
Group(equations=[
ContinuityEquation(dest='fluid',
sources=['fluid', 'walls', 'ellipsoid']),
ContinuityEquation(dest='ellipsoid', sources=['fluid']),
ContinuityEquation(dest='walls', sources=['fluid']),
LaminarViscosity(
dest='fluid', sources=['fluid', 'walls'], nu=self.nu),
MomentumEquation(dest='fluid',
sources=['fluid', 'walls'],
alpha=self.alpha,
beta=0.0,
c0=self.co),
ViscosityRigidBody(dest='fluid',
sources=['ellipsoid'],
nu=self.nu,
rho0=self.rho),
PressureRigidBody(dest='fluid',
sources=['ellipsoid'],
rho0=self.rho),
XSPHCorrection(dest='fluid', sources=['fluid']),
]),
Group(
equations=[RigidBodyMoments(dest='ellipsoid', sources=None)]),
Group(equations=[RigidBodyMotion(dest='ellipsoid', sources=None)]),
]
return equations
def create_equations(self):
equations = [
Group(equations=[
BodyForce(dest='cube', sources=None, gy=-9.81),
SummationDensity(dest='cube', sources=['fluid', 'cube'])
],
real=False),
Group(equations=[
TaitEOSHGCorrection(dest='cube',
sources=None,
rho0=self.solid_rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='fluid',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='tank',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
],
real=False),
Group(equations=[
ContinuityEquation(
dest='fluid',
sources=['fluid', 'tank', 'cube'],
),
ContinuityEquation(
dest='tank',
sources=['fluid', 'tank', 'cube'],
),
MomentumEquation(dest='fluid',
sources=['fluid', 'tank', 'cube'],
alpha=self.alpha,
beta=0.0,
c0=self.co,
gy=-9.81),
LiuFluidForce(
dest='fluid',
sources=['cube'],
),
XSPHCorrection(dest='fluid', sources=['fluid', 'tank']),
]),
Group(equations=[
RigidBodyCollision(dest='cube', sources=['tank'], kn=1e5)
]),
Group(equations=[RigidBodyMoments(dest='cube', sources=None)]),
Group(equations=[RigidBodyMotion(dest='cube', sources=None)]),
]
return equations
def create_equations(self):
equations = [
Group(equations=[
BodyForce(dest='cube', sources=None, gy=-9.81),
],
real=False),
Group(equations=[
ContinuityEquation(dest='fluid',
sources=['fluid', 'tank', 'cube']),
ContinuityEquation(dest='tank',
sources=['tank', 'fluid', 'cube'])
]),
# Tait equation of state
Group(equations=[
TaitEOSHGCorrection(dest='fluid',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='tank',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
],
real=False),
Group(equations=[
MomentumEquation(dest='fluid',
sources=['fluid', 'tank'],
alpha=self.alpha,
beta=0.0,
c0=self.co,
gy=-9.81),
AkinciRigidFluidCoupling(dest='fluid', sources=['cube']),
XSPHCorrection(dest='fluid', sources=['fluid', 'tank']),
]),
Group(equations=[
RigidBodyCollision(
dest='cube', sources=['tank', 'cube'], kn=1e5)
]),
Group(equations=[RigidBodyMoments(dest='cube', sources=None)]),
Group(equations=[RigidBodyMotion(dest='cube', sources=None)]),
]
return equations
def create_equations(self):
equations = [
# Equation of state
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
TaitEOSHGCorrection(dest='boundary',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
],
real=False),
# Continuity Momentum and XSPH equations
Group(equations=[
ContinuityEquation(dest='fluid', sources=['fluid', 'boundary'
]),
ContinuityEquation(dest='boundary', sources=['fluid']),
MomentumEquation(dest='fluid',
sources=['fluid', 'boundary'],
c0=c0,
alpha=alpha,
beta=beta,
gz=-9.81,
tensile_correction=True),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid'], eps=eps)
])
]
return equations
def create_equations(self):
h0 = dx * hdx
co = 10.0 * self.geom.get_max_speed(g=9.81)
gamma = 7.0
alpha = 0.5
beta = 0.0
B = co * co * rho0 / gamma
equations = [
Group(equations=[
BodyForce(dest='obstacle', sources=None, gz=-9.81),
NumberDensity(dest='obstacle', sources=['obstacle']),
NumberDensity(dest='boundary', sources=['boundary']),
], ),
# Equation of state
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=rho0,
c0=co,
gamma=gamma),
TaitEOSHGCorrection(dest='boundary',
sources=None,
rho0=rho0,
c0=co,
gamma=gamma),
TaitEOSHGCorrection(dest='obstacle',
sources=None,
rho0=rho0,
c0=co,
gamma=gamma),
],
real=False),
# Continuity, momentum and xsph equations
Group(equations=[
ContinuityEquation(dest='fluid',
sources=['fluid', 'boundary', 'obstacle']),
ContinuityEquation(dest='boundary', sources=['fluid']),
ContinuityEquation(dest='obstacle', sources=['fluid']),
MomentumEquation(dest='fluid',
sources=['fluid', 'boundary'],
alpha=alpha,
beta=beta,
gz=-9.81,
c0=co,
tensile_correction=True),
PressureRigidBody(dest='fluid',
sources=['obstacle'],
rho0=rho0),
XSPHCorrection(dest='fluid', sources=['fluid']),
RigidBodyCollision(dest='obstacle',
sources=['boundary'],
k=1.0,
d=2.0,
eta=0.1,
kt=0.1),
]),
Group(equations=[RigidBodyMoments(dest='obstacle', sources=None)]),
Group(equations=[RigidBodyMotion(dest='obstacle', sources=None)]),
]
return equations
def get_equations(self):
from pysph.sph.equation import Group
from pysph.sph.wc.basic import (MomentumEquation, TaitEOS,
TaitEOSHGCorrection,
UpdateSmoothingLengthFerrari)
from pysph.sph.wc.basic import (ContinuityEquationDeltaSPH,
MomentumEquationDeltaSPH)
from pysph.sph.basic_equations import \
(ContinuityEquation, SummationDensity, XSPHCorrection)
from pysph.sph.wc.viscosity import LaminarViscosity
equations = []
g1 = []
all = self.fluids + self.solids
if self.summation_density:
g0 = []
for name in self.fluids:
g0.append(SummationDensity(dest=name, sources=all))
equations.append(Group(equations=g0, real=False))
for name in self.fluids:
g1.append(
TaitEOS(dest=name,
sources=None,
rho0=self.rho0,
c0=self.c0,
gamma=self.gamma))
if self.hg_correction:
# This correction applies only to solids.
for name in self.solids:
g1.append(
TaitEOSHGCorrection(dest=name,
sources=None,
rho0=self.rho0,
c0=self.c0,
gamma=self.gamma))
equations.append(Group(equations=g1, real=False))
g2 = []
for name in self.solids:
g2.append(ContinuityEquation(dest=name, sources=self.fluids))
for name in self.fluids:
if self.delta_sph:
other = all[:]
other.remove(name)
g2.append(
ContinuityEquationDeltaSPH(dest=name,
sources=[name],
c0=self.c0,
delta=self.delta))
if len(other) > 0:
g2.append(ContinuityEquation(dest=name, sources=other))
g2.append(
MomentumEquationDeltaSPH(
dest=name,
sources=[name],
rho0=self.rho0,
c0=self.c0,
alpha=self.alpha,
gx=self.gx,
gy=self.gy,
gz=self.gz,
))
if len(other) > 0:
g2.append(
MomentumEquation(
dest=name,
sources=other,
c0=self.c0,
alpha=self.alpha,
beta=self.beta,
gx=self.gx,
gy=self.gy,
gz=self.gz,
tensile_correction=self.tensile_correction))
g2.append(XSPHCorrection(dest=name, sources=[name]))
else:
if not self.summation_density:
g2.append(ContinuityEquation(dest=name, sources=all))
g2.extend([
MomentumEquation(
dest=name,
sources=all,
alpha=self.alpha,
beta=self.beta,
gx=self.gx,
gy=self.gy,
gz=self.gz,
c0=self.c0,
tensile_correction=self.tensile_correction),
XSPHCorrection(dest=name, sources=[name])
])
if abs(self.nu) > 1e-14:
eq = LaminarViscosity(dest=name,
sources=self.fluids,
nu=self.nu)
g2.insert(-1, eq)
equations.append(Group(equations=g2))
if self.update_h:
g3 = [
UpdateSmoothingLengthFerrari(dest=x,
sources=None,
dim=self.dim,
hdx=self.hdx) for x in self.fluids
]
equations.append(Group(equations=g3, real=False))
return equations
def create_equations(self):
equations = [
Group(
equations=[
BodyForce(dest='cube', sources=None, gy=-9.81),
BodyForce(dest='wood', sources=None, gy=-9.81),
BodyForce(dest='small_tank', sources=None, gy=-9.81),
BodyForce(dest='outside', sources=None, gy=-9.81),
SummationDensity(dest='cube', sources=['fluid', 'cube']),
SummationDensity(dest='wood', sources=['fluid', 'wood']),
SummationDensity(dest='small_tank',
sources=['fluid', 'small_tank']),
SummationDensity(dest='outside',
sources=['fluid', 'outside'])
# NumberDensity(dest='cube', sources=['cube']),
],
real=False),
Group(equations=[
TaitEOSHGCorrection(dest='wood',
sources=None,
rho0=self.wood_rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='cube',
sources=None,
rho0=self.solid_rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='fluid',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='big_tank',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='small_tank',
sources=None,
rho0=self.wood_rho,
c0=self.co,
gamma=7.0),
TaitEOSHGCorrection(dest='outside',
sources=None,
rho0=self.ro,
c0=self.co,
gamma=7.0),
],
real=False),
Group(equations=[
ContinuityEquation(
dest='fluid',
sources=[
'fluid', 'small_tank', 'cube', 'wood', 'big_tank',
'outside'
],
),
ContinuityEquation(
dest='big_tank',
sources=[
'fluid', 'big_tank', 'cube', 'wood', 'small_tank',
'outside'
],
),
MomentumEquation(dest='fluid',
sources=['fluid', 'big_tank'],
alpha=self.alpha,
beta=0.0,
c0=self.co,
gy=-9.81),
LiuFluidForce(
dest='fluid',
sources=['cube'],
),
LiuFluidForce(
dest='fluid',
sources=['wood'],
),
LiuFluidForce(
dest='fluid',
sources=['small_tank'],
),
LiuFluidForce(
dest='fluid',
sources=['outside'],
),
# PressureRigidBody(dest='fluid', sources=['cube'],
# rho0=1500),
XSPHCorrection(dest='fluid', sources=['fluid', 'big_tank']),
]),
Group(equations=[
RigidBodyCollision(
dest='cube',
sources=['big_tank', 'wood', 'small_tank', 'outside'],
kn=1e6)
]),
Group(equations=[RigidBodyMoments(dest='cube', sources=None)]),
Group(equations=[RigidBodyMotion(dest='cube', sources=None)]),
Group(equations=[
RigidBodyCollision(
dest='wood',
sources=['big_tank', 'cube', 'small_tank', 'outside'],
kn=1e6)
]),
Group(equations=[RigidBodyMoments(dest='wood', sources=None)]),
Group(equations=[RigidBodyMotion(dest='wood', sources=None)]),
Group(equations=[
RigidBodyCollision(
dest='small_tank',
sources=['big_tank', 'cube', 'wood', 'outside'],
kn=1e6)
]),
Group(
equations=[RigidBodyMoments(dest='small_tank', sources=None)]),
Group(
equations=[RigidBodyMotion(dest='small_tank', sources=None)]),
Group(equations=[
RigidBodyCollision(
dest='outside',
sources=['big_tank', 'cube', 'small_tank', 'wood'],
kn=1e6)
]),
Group(equations=[RigidBodyMoments(dest='outside', sources=None)]),
Group(equations=[RigidBodyMotion(dest='outside', sources=None)]),
]
return equations
def create_equations(self):
equations = [
Group(equations=[
BodyForce(dest='block', sources=None, gy=gy),
NumberDensity(dest='block', sources=['block']),
NumberDensity(dest='solid', sources=['solid']),
], ),
# 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),
TaitEOSHGCorrection(dest='solid',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
TaitEOSHGCorrection(dest='block',
sources=None,
rho0=rho0,
c0=c0,
gamma=gamma),
], ),
# Main acceleration block
Group(equations=[
# Continuity equation with dissipative corrections for fluid on fluid
ContinuityEquationDeltaSPH(
dest='fluid', sources=['fluid'], c0=c0, delta=0.1),
ContinuityEquation(dest='fluid', sources=['solid', 'block']),
ContinuityEquation(dest='solid', sources=['fluid']),
ContinuityEquation(dest='block', sources=['fluid']),
# Momentum equation
MomentumEquation(dest='fluid',
sources=['fluid', 'solid', 'block'],
alpha=alpha,
beta=beta,
gy=-9.81,
c0=c0,
tensile_correction=True),
PressureRigidBody(dest='fluid',
sources=['block', 'solid'],
rho0=rho0),
ViscosityRigidBody(
dest='fluid', sources=['block', 'solid'
], rho0=rho0, nu=nu),
# Position step with XSPH
XSPHCorrection(dest='fluid', sources=['fluid']),
RigidBodyCollision(dest='block',
sources=['solid'],
k=1.0,
d=2.0,
eta=0.1,
kt=0.1),
]),
Group(equations=[RigidBodyMoments(dest='block', sources=None)]),
Group(equations=[RigidBodyMotion(dest='block', sources=None)]),
]
return equations
integrator=integrator,
dt=dt,
tf=tf,
adaptive_timestep=True,
n_damp=50,
fixed_h=False)
# create the equations
equations = [
# Equation of state
Group(equations=[
TaitEOS(dest='fluid', sources=None, rho0=ro, c0=co, gamma=gamma),
TaitEOSHGCorrection(dest='boundary',
sources=None,
rho0=ro,
c0=co,
gamma=gamma),
],
real=False),
Group(equations=[
# Continuity equation with dissipative corrections for fluid on fluid
ContinuityEquationDeltaSPH(
dest='fluid', sources=['fluid'], c0=co, delta=0.1),
ContinuityEquation(dest='fluid', sources=['boundary']),
ContinuityEquation(dest='boundary', sources=['fluid']),
# Momentum equation
MomentumEquation(dest='fluid',
sources=['fluid', 'boundary'],
def create_equations(self):
# Formulation for REF1
equations1 = [
# Spoon Equations
Group(
equations=[
HarmonicOscilllator(dest='spoon',
sources=None,
A=0.5,
omega=0.2),
# 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=1.25,
y=tahiniH,
r=0.15,
fill_rate=7),
DiffuseH2O(
dest='tahini', sources=['tahini'], 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='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=0.5,
omega=0.2),
# 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=Cx,
y=tahiniH,
r=0.15,
fill_rate=5),
DiffuseH2O(
dest='tahini', sources=['tahini'], 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='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