def create_equations(self):
sy11_equations = [
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])],
real=False),
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
SY11ColorGradient(dest='fluid', sources=['fluid'])
],
real=False),
Group(equations=[
ScaleSmoothingLength(dest='fluid',
sources=None,
factor=factor1)
],
real=False,
update_nnps=True),
Group(equations=[SY11DiracDelta(dest='fluid', sources=['fluid'])],
real=False),
Group(equations=[
InterfaceCurvatureFromNumberDensity(
dest='fluid',
sources=['fluid'],
with_morris_correction=True),
],
real=False),
Group(
equations=[
ScaleSmoothingLength(dest='fluid',
sources=None,
factor=factor2)
],
real=False,
update_nnps=True,
),
Group(equations=[
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=0.0),
MomentumEquationViscosity(dest='fluid',
sources=['fluid'],
nu=nu),
ShadlooYildizSurfaceTensionForce(dest='fluid',
sources=None,
sigma=sigma),
], )
]
adami_equations = [
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])],
real=False),
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
],
real=False),
Group(equations=[
AdamiColorGradient(dest='fluid', sources=['fluid']),
],
real=False),
Group(equations=[
AdamiReproducingDivergence(dest='fluid',
sources=['fluid'],
dim=2),
],
real=False),
Group(equations=[
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=p0),
MomentumEquationViscosityAdami(dest='fluid',
sources=['fluid']),
CSFSurfaceTensionForceAdami(
dest='fluid',
sources=None,
)
], )
]
adami_stress_equations = [
Group(equations=[
SummationDensity(dest='fluid', sources=['fluid']),
],
real=False),
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=rho0,
c0=c0,
gamma=7,
p0=p0),
],
real=False),
Group(equations=[
ColorGradientAdami(dest='fluid', sources=['fluid']),
],
real=False),
Group(equations=[
ConstructStressMatrix(dest='fluid',
sources=None,
sigma=sigma,
d=2)
],
real=False),
Group(equations=[
MomentumEquationPressureGradientAdami(dest='fluid',
sources=['fluid']),
MomentumEquationViscosityAdami(dest='fluid', sources=['fluid'
]),
SurfaceForceAdami(dest='fluid', sources=['fluid']),
]),
]
tvf_equations = [
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])],
real=False),
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
SmoothedColor(dest='fluid', sources=['fluid']),
],
real=False),
Group(equations=[
MorrisColorGradient(dest='fluid',
sources=['fluid'],
epsilon=epsilon),
],
real=False),
Group(equations=[
InterfaceCurvatureFromNumberDensity(
dest='fluid',
sources=['fluid'],
with_morris_correction=True),
],
real=False),
Group(equations=[
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=p0),
MomentumEquationViscosity(dest='fluid',
sources=['fluid'],
nu=nu),
CSFSurfaceTensionForce(dest='fluid', sources=None,
sigma=sigma),
MomentumEquationArtificialStress(dest='fluid',
sources=['fluid']),
], )
]
morris_equations = [
Group(equations=[
SummationDensitySourceMass(dest='fluid', sources=['fluid']),
],
real=False,
update_nnps=False),
Group(equations=[
TaitEOS(dest='fluid',
sources=None,
rho0=rho0,
c0=c0,
gamma=1.0),
SmoothedColor(dest='fluid', sources=[
'fluid',
]),
ScaleSmoothingLength(dest='fluid',
sources=None,
factor=2.0 / 3.0),
],
real=False,
update_nnps=False),
Group(equations=[
MorrisColorGradient(dest='fluid',
sources=[
'fluid',
],
epsilon=epsilon),
],
real=False,
update_nnps=False),
Group(equations=[
InterfaceCurvatureFromDensity(dest='fluid',
sources=['fluid'],
with_morris_correction=True),
ScaleSmoothingLength(dest='fluid', sources=None, factor=1.5),
],
real=False,
update_nnps=False),
Group(equations=[
MomentumEquationPressureGradientMorris(dest='fluid',
sources=['fluid']),
MomentumEquationViscosityMorris(dest='fluid',
sources=['fluid']),
CSFSurfaceTensionForce(dest='fluid', sources=None,
sigma=sigma),
],
update_nnps=False)
]
if self.options.scheme == 'tvf':
return tvf_equations
elif self.options.scheme == 'adami_stress':
return adami_stress_equations
elif self.options.scheme == 'adami':
return adami_equations
elif self.options.scheme == 'shadloo':
return sy11_equations
else:
return morris_equations
def create_equations(self):
sy11_equations = [
# We first compute the mass and number density of the fluid
# phase. This is used in all force computations henceforth. The
# number density (1/volume) is explicitly set for the solid phase
# and this isn't modified for the simulation.
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])]),
# Given the updated number density for the fluid, we can update
# the fluid pressure. Additionally, we can compute the Shepard
# Filtered velocity required for the no-penetration boundary
# condition. Also compute the gradient of the color function to
# compute the normal at the interface.
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
SY11ColorGradient(dest='fluid', sources=['fluid'])
]),
#################################################################
# Begin Surface tension formulation
#################################################################
# Scale the smoothing lengths to determine the interface
# quantities.
Group(equations=[
ScaleSmoothingLength(dest='fluid',
sources=None,
factor=factor1)
],
update_nnps=False),
# Compute the discretized dirac delta with respect to the new
# smoothing length.
Group(equations=[SY11DiracDelta(dest='fluid',
sources=['fluid'])], ),
# Compute the interface curvature using the modified smoothing
# length and interface normals computed in the previous Group.
Group(equations=[
InterfaceCurvatureFromNumberDensity(
dest='fluid',
sources=['fluid'],
with_morris_correction=True),
], ),
# Now rescale the smoothing length to the original value for the
# rest of the computations.
Group(
equations=[
ScaleSmoothingLength(dest='fluid',
sources=None,
factor=factor2)
],
update_nnps=False,
),
#################################################################
# End Surface tension formulation
#################################################################
# The main acceleration block
Group(
equations=[
# Gradient of pressure for the fluid phase using the
# number density formulation. No penetration boundary
# condition using Adami et al's generalized wall boundary
# condition. The extrapolated pressure and density on the
# wall particles is used in the gradient of pressure to
# simulate a repulsive force.
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=p0),
# Artificial viscosity for the fluid phase.
MomentumEquationViscosity(dest='fluid',
sources=['fluid'],
nu=nu),
# Surface tension force for the SY11 formulation
ShadlooYildizSurfaceTensionForce(dest='fluid',
sources=None,
sigma=sigma),
# Artificial stress for the fluid phase
MomentumEquationArtificialStress(dest='fluid',
sources=['fluid']),
], )
]
morris_equations = [
# We first compute the mass and number density of the fluid
# phase. This is used in all force computations henceforth. The
# number density (1/volume) is explicitly set for the solid phase
# and this isn't modified for the simulation.
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])]),
# Given the updated number density for the fluid, we can update
# the fluid pressure. Additionally, we can compute the Shepard
# Filtered velocity required for the no-penetration boundary
# condition. Also compute the smoothed color based on the color
# index for a particle.
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
SmoothedColor(dest='fluid', sources=['fluid'], smooth=True),
]),
#################################################################
# Begin Surface tension formulation
#################################################################
# Compute the gradient of the smoothed color field. At the end of
# this Group, we will have the interface normals and the
# discretized dirac delta function for the fluid-fluid interface.
Group(equations=[
MorrisColorGradient(dest='fluid',
sources=['fluid'],
epsilon=epsilon),
], ),
# Compute the interface curvature computed in the previous Group.
Group(equations=[
InterfaceCurvatureFromNumberDensity(
dest='fluid',
sources=['fluid'],
with_morris_correction=True),
], ),
#################################################################
# End Surface tension formulation
#################################################################
# The main acceleration block
Group(
equations=[
# Gradient of pressure for the fluid phase
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=p0),
# Artificial viscosity for the fluid phase.
MomentumEquationViscosity(dest='fluid',
sources=['fluid'],
nu=nu),
# Surface tension force for the Morris formulation
CSFSurfaceTensionForce(dest='fluid',
sources=None,
sigma=sigma),
# Artificial stress for the fluid phase
MomentumEquationArtificialStress(dest='fluid',
sources=['fluid']),
], )
]
adami_equations = [
# We first compute the mass and number density of the fluid
# phase. This is used in all force computations henceforth. The
# number density (1/volume) is explicitly set for the solid phase
# and this isn't modified for the simulation.
Group(
equations=[SummationDensity(dest='fluid', sources=['fluid'])]),
# Given the updated number density for the fluid, we can update
# the fluid pressure. Additionally, we can compute the Shepard
# Filtered velocity required for the no-penetration boundary
# condition.
Group(equations=[
StateEquation(dest='fluid', sources=None, rho0=rho0, p0=p0),
]),
#################################################################
# Begin Surface tension formulation
#################################################################
# Compute the gradient of the color field.
Group(equations=[
AdamiColorGradient(dest='fluid', sources=['fluid']),
], ),
# Compute the interface curvature using the color gradients
# computed in the previous Group.
Group(equations=[
AdamiReproducingDivergence(dest='fluid',
sources=['fluid'],
dim=2),
], ),
#################################################################
# End Surface tension formulation
#################################################################
# The main acceleration block
Group(
equations=[
# Gradient of pressure for the fluid phase
MomentumEquationPressureGradient(dest='fluid',
sources=['fluid'],
pb=p0),
# Artificial viscosity for the fluid phase.
MomentumEquationViscosity(dest='fluid',
sources=['fluid'],
nu=nu),
# Surface tension force for the CSF formulation
CSFSurfaceTensionForce(dest='fluid',
sources=None,
sigma=sigma),
# Artificial stress for the fluid phase
MomentumEquationArtificialStress(dest='fluid',
sources=['fluid']),
], )
]
if self.options.scheme == 'morris':
return morris_equations
elif self.options.scheme == 'adami':
return adami_equations
else:
return sy11_equations