f_N_function = interpolate(f_N, V)
coupling_boundary = TopBoundary()
bottom_boundary = BottomBoundary()
# Define initial value
u_n = interpolate(u_D, V)
u_n.rename("T", "")
# Adapter definition and initialization
precice = Adapter(adapter_config_filename="precice-adapter-config.json")
precice_dt = precice.initialize(coupling_boundary, mesh, V)
# Create a FEniCS Expression to define and control the coupling boundary values
coupling_expression = precice.create_coupling_expression()
# Assigning appropriate dt
dt = Constant(0)
dt.assign(np.min([fenics_dt, precice_dt]))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
F = u * v / dt * dx + alpha * dot(grad(u), grad(v)) * dx - u_n * v / dt * dx
# apply constant Dirichlet boundary condition at bottom edge
# apply Dirichlet boundary condition on coupling interface
bcs = [DirichletBC(V, coupling_expression, coupling_boundary), DirichletBC(V, u_D, bottom_boundary)]
a, L = lhs(F), rhs(F)
precice, precice_dt, initial_data = None, 0.0, None
# Initialize the adapter according to the specific participant
if problem is ProblemType.DIRICHLET:
precice = Adapter(adapter_config_filename="precice-adapter-config-D.json")
precice_dt = precice.initialize(coupling_boundary, mesh, V)
initial_data = precice.initialize_data(f_N_function)
elif problem is ProblemType.NEUMANN:
precice = Adapter(adapter_config_filename="precice-adapter-config-N.json")
precice_dt = precice.initialize(coupling_boundary, mesh, V_g)
initial_data = precice.initialize_data(u_D_function)
boundary_marker = False
coupling_expression = precice.create_coupling_expression(initial_data)
dt = Constant(0)
dt.assign(np.min([fenics_dt, precice_dt]))
# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
f = Expression('beta + gamma*x[0]*x[0] - 2*gamma*t - 2*(1-gamma) - 2*alpha',
degree=2,
alpha=alpha,
beta=beta,
gamma=gamma,
t=0)
F = u * v / dt * dx + dot(grad(u), grad(v)) * dx - (u_n / dt + f) * v * dx