flux = Function(V_g)
flux.rename("Flux", "")
while precice.is_coupling_ongoing():
if precice.is_action_required(precice.action_write_iteration_checkpoint()): # write checkpoint
precice.store_checkpoint(u_n, t, n)
read_data = precice.read_data()
if problem is ProblemType.DIRICHLET and (domain_part is DomainPart.CIRCULAR or domain_part is DomainPart.RECTANGLE):
# We have to data for an arbitrary point that is not on the circle, to obtain exact solution.
# See https://github.com/precice/fenics-adapter/issues/113 for details.
read_data[(0, 0)] = u_D(0, 0)
# Update the coupling expression with the new read data
precice.update_coupling_expression(coupling_expression, read_data)
dt.assign(np.min([fenics_dt, precice_dt]))
# Compute solution u^n+1, use bcs u_D^n+1, u^n and coupling bcs
solve(a == L, u_np1, bcs)
# Write data to preCICE according to which problem is being solved
if problem is ProblemType.DIRICHLET:
# Dirichlet problem reads temperature and writes flux on boundary to Neumann problem
determine_gradient(V_g, u_np1, flux)
precice.write_data(flux)
elif problem is ProblemType.NEUMANN:
# Neumann problem reads flux and writes temperature on boundary to Dirichlet problem
precice.write_data(u_np1)
# output solution and reference solution at t=0, n=0
n = 0
print('output u^%d and u_ref^%d' % (n, n))
solution_out << u_n
ranks << mesh_rank
while precice.is_coupling_ongoing():
# write checkpoint
if precice.is_action_required(precice.action_write_iteration_checkpoint()):
precice.store_checkpoint(u_n, t, n)
read_data = precice.read_data()
# Update the coupling expression with the new read data
precice.update_coupling_expression(volume_term, read_data)
f.assign(interpolate(volume_term, V))
dt_inv.assign(1 / dt)
# Compute solution u^n+1, use bcs u^n and coupling bcs
a, L = lhs(F), rhs(F)
solve(a == L, u_np1, bc)
# Write data to preCICE according to which problem is being solved
precice.write_data(u_np1)
dt = precice.advance(dt)
# roll back to checkpoint
if precice.is_action_required(precice.action_read_iteration_checkpoint()):