def set_solid_variational_form(self, neumann_bcs):
U = self.Us
dU, L = split(U)
V = TestFunction(self.FS_S)
v, w = split(V)
#v = V
# parameters
rho = self.rho()
phi0 = Constant(self.params['Parameter']['phi'])
m = self.sum_fluid_mass()
# Kinematics
n = FacetNormal(self.mesh)
#Return the dimension of the space this cell is embedded in
d = dU.geometric_dimension()
self.I = Identity(d)
self.F = variable(self.I + ufl_grad(dU))
self.J = variable(det(self.F))
self.C = variable(self.F.T * self.F)
self.Psi = self.material.constitutive_law(J=self.J, C=self.C, phi=phi0)
Psic = self.Psi * dx + L * (self.J - Constant(1) - m / rho) * dx
for condition, boundary in neumann_bcs:
Psic += dot(condition * n, dU) * self.ds(boundary)
Form = derivative(Psic, U, V)
dF = derivative(Form, U, TrialFunction(self.FS_S))
return Form, dF
def set_solid_variational_form(self, neumann_bcs):
U = self.Us
dU, L = split(U)
V = TestFunction(self.FS_S)
v, w = split(V)
# parameters
rho = Constant(self.params.params['rho'])
# fluid Solution
m = self.mf
# Kinematics
n = FacetNormal(self.mesh)
d = dU.geometric_dimension()
I = Identity(d)
F = variable(I + ufl_grad(dU))
J = variable(det(F))
C = variable(F.T*F)
# modified Cauchy-Green invariants
I1 = variable(J**(-2/3) * tr(C))
I2 = variable(J**(-4/3) * 0.5 * (tr(C)**2 - tr(C*C)))
Psi = self.material.constitutive_law(F, M=self.mf, rho=self.rho(), phi0=self.phi())
Psic = Psi*dx + L*(J-m/rho-Constant(1))*dx
for boundary, condition in neumann_bcs.items():
Psic += dot(condition*n, dU)*self.ds(boundary)
Form = derivative(Psic, U, V)
dF = derivative(Form, U, TrialFunction(self.FS_S))
return Form, dF
def fluid_solid_coupling(self, t):
dU, L = self.Us.split(True)
p = self.p
q = TestFunction(self.FS_F)
rho = self.rho()
phi0 = self.phi()
d = dU.geometric_dimension()
I = Identity(d)
F = variable(I + ufl_grad(dU))
J = variable(det(F))
Psi = self.material.constitutive_law(F, M=self.mf, rho=self.rho(), phi0=self.phi())
phi = (self.mf + rho*phi0)
Jphi = variable(J*phi)
p = diff(Psi, Jphi) - L
self.p = project(p, self.FS_F)
def set_fluid_variational_form(self):
m = self.mf
m_n = self.mf_n
vm = TestFunction(self.FS_F)
dU, L = self.Us.split(True)
dU_n, L_n = self.Us_n.split(True)
# Parameters
self.qi = self.q_in()
q_out = self.q_out()
rho = self.rho()
si = Constant(0.0)
k = Constant(1/self.dt())
th, th_ = self.theta()
# Kinematics from solid
d = dU.geometric_dimension()
I = Identity(d)
F = variable(I + ufl_grad(dU))
J = variable(det(F))
# VK = TensorFunctionSpace(self.mesh, "P", 1)
# if d == 2:
# exp = Expression((('0.5', '0.0'),('0.0', '1.0')), degree=1)
# elif d == 3:
# exp = Expression((('1.0', '0.0', '0.0'),('0.0', '1.0', '0.0'),
# ('0.0', '0.0', '1.0')), degree=1)
# self.K = project(Ki*exp, VK, solver_type='mumps')
# theta-rule / Crank-Nicolson
M = th*m + th_*m_n
# Fluid variational form
A = variable(rho * J * inv(F) * self.K() * inv(F.T))
Form = k*(m - m_n)*vm*dx + dot(grad(M), k*(dU-dU_n))*vm*dx -\
inner(-A*grad(self.p), grad(vm))*dx + rho*si*vm*dx
# Add inflow terms
Form += -self.rho()*self.qi*vm*dx
# Add outflow term
Form += self.rho()*q_out*vm*dx
dF = derivative(Form, m, TrialFunction(self.FS_F))
return Form, dF
def calculate_flow_vector(self):
FS = VectorFunctionSpace(self.mesh, 'P', 1)
dU, L = self.Us.split(True)
m = TrialFunction(self.FS_V)
mv = TestFunction(self.FS_V)
# Parameters
rho = Constant(self.rho())
phi0 = self.phi()
k = Constant(1/self.dt())
# Kinematics from solid
d = dU.geometric_dimension()
I = Identity(d)
F = variable(I + ufl_grad(dU))
J = variable(det(F))
phi = (self.mf + rho*phi0)
a = (1/rho)*inner(F*m, mv)*dx
L = inner(-J*self.K()*inv(F.T)*grad(self.p), mv)*dx
solve(a == L, self.Uf, solver_parameters={"linear_solver": "minres",
"preconditioner": "hypre_amg"})
def Grad(v):
return ufl_grad(v)
def Grad(v):
return ufl_grad(v)