def __init__(self, parameters=None, solver="ipcs"):
"Create Navier-Stokes problem"
self.parameters = Parameters("problem_parameters")
# Create solver
if solver == "taylor-hood":
info("Using Taylor-Hood based Navier-Stokes solver")
self.solver = TaylorHoodSolver(self)
elif solver == "ipcs":
info("Using IPCS based Navier-Stokes solver")
self.solver = NavierStokesSolver(self)
else:
error("Unknown Navier--Stokes solver: %s" % solver)
# Set up parameters
self.parameters.add(self.solver.parameters)
def __init__(self, parameters=None, solver="ipcs"):
"Create Navier-Stokes problem"
self.parameters = Parameters("problem_parameters")
# Create solver
if solver == "taylor-hood":
info("Using Taylor-Hood based Navier-Stokes solver")
self.solver = TaylorHoodSolver(self)
elif solver == "ipcs":
info("Using IPCS based Navier-Stokes solver")
self.solver = NavierStokesSolver(self)
else:
error("Unknown Navier--Stokes solver: %s" % solver)
# Set up parameters
self.parameters.add(self.solver.parameters)
class NavierStokes(CBCProblem):
"Base class for all Navier-Stokes problems"
def __init__(self, parameters=None, solver="ipcs"):
"Create Navier-Stokes problem"
self.parameters = Parameters("problem_parameters")
# Create solver
if solver == "taylor-hood":
info("Using Taylor-Hood based Navier-Stokes solver")
self.solver = TaylorHoodSolver(self)
elif solver == "ipcs":
info("Using IPCS based Navier-Stokes solver")
self.solver = NavierStokesSolver(self)
else:
error("Unknown Navier--Stokes solver: %s" % solver)
# Set up parameters
self.parameters.add(self.solver.parameters)
def solve(self):
"Solve and return computed solution (u, p)"
# Update solver parameters
self.solver.parameters.update(self.parameters["solver_parameters"])
# Call solver
return self.solver.solve()
def step(self, dt):
"Make a time step of size dt"
# Update solver parameters
self.solver.parameters.update(self.parameters["solver_parameters"])
# Call solver
return self.solver.step(dt)
def update(self, t):
"Propagate values to next time step"
return self.solver.update(t)
def solution(self):
"Return current solution values"
return self.solver.solution()
def solution_values(self):
"Return solution values at t_{n-1} and t_n"
return self.solver.solution_values()
#--- Functions that must be overloaded by subclasses ---
def mesh(self):
"Return mesh"
missing_function("mesh")
#--- Functions that may optionally be overloaded by subclasses ---
def density(self):
"Return density"
return 1.0
def viscosity(self):
"Return viscosity"
return 1.0
def body_force(self, V):
"Return body force f"
return []
def boundary_traction(self, V):
"Return boundary traction g = sigma(u, p) * n"
return []
def mesh_velocity(self, V):
"Return mesh velocity (for ALE formulations)"
w = Constant((0,)*V.mesh().geometry().dim())
return w
def boundary_conditions(self, V, Q):
"Return boundary conditions for velocity and pressure"
return [], []
def velocity_dirichlet_values(self):
"Return Dirichlet boundary values for the velocity"
return []
def velocity_dirichlet_boundaries(self):
"Return Dirichlet boundaries for the velocity"
return []
def pressure_dirichlet_values(self):
"Return Dirichlet boundary conditions for the velocity"
return []
def pressure_dirichlet_boundaries(self):
"Return Dirichlet boundaries for the velocity"
return []
def velocity_initial_condition(self):
"Return initial condition for velocity"
return None
def pressure_initial_condition(self):
"Return initial condition for pressure"
return 0
def end_time(self):
"Return end time"
return 1.0
def time_step(self):
"Return preferred time step"
return None
def max_velocity(self):
"Return maximum velocity (used for selecting time step)"
return 1.0
def __str__(self):
"Return a short description of the problem"
return "Navier-Stokes problem"
class NavierStokes(CBCProblem):
"Base class for all Navier-Stokes problems"
def __init__(self, parameters=None, solver="ipcs"):
"Create Navier-Stokes problem"
self.parameters = Parameters("problem_parameters")
# Create solver
if solver == "taylor-hood":
info("Using Taylor-Hood based Navier-Stokes solver")
self.solver = TaylorHoodSolver(self)
elif solver == "ipcs":
info("Using IPCS based Navier-Stokes solver")
self.solver = NavierStokesSolver(self)
else:
error("Unknown Navier--Stokes solver: %s" % solver)
# Set up parameters
self.parameters.add(self.solver.parameters)
def solve(self):
"Solve and return computed solution (u, p)"
# Update solver parameters
self.solver.parameters.update(self.parameters["solver_parameters"])
# Call solver
return self.solver.solve()
def step(self, dt):
"Make a time step of size dt"
# Update solver parameters
self.solver.parameters.update(self.parameters["solver_parameters"])
# Call solver
return self.solver.step(dt)
def update(self, t):
"Propagate values to next time step"
return self.solver.update(t)
def solution(self):
"Return current solution values"
return self.solver.solution()
def solution_values(self):
"Return solution values at t_{n-1} and t_n"
return self.solver.solution_values()
#--- Functions that must be overloaded by subclasses ---
def mesh(self):
"Return mesh"
missing_function("mesh")
#--- Functions that may optionally be overloaded by subclasses ---
def density(self):
"Return density"
return 1.0
def viscosity(self):
"Return viscosity"
return 1.0
def body_force(self, V):
"Return body force f"
return []
def boundary_traction(self, V):
"Return boundary traction g = sigma(u, p) * n"
return []
def mesh_velocity(self, V):
"Return mesh velocity (for ALE formulations)"
w = Constant((0, ) * V.mesh().geometry().dim())
return w
def boundary_conditions(self, V, Q):
"Return boundary conditions for velocity and pressure"
return [], []
def velocity_dirichlet_values(self):
"Return Dirichlet boundary values for the velocity"
return []
def velocity_dirichlet_boundaries(self):
"Return Dirichlet boundaries for the velocity"
return []
def pressure_dirichlet_values(self):
"Return Dirichlet boundary conditions for the velocity"
return []
def pressure_dirichlet_boundaries(self):
"Return Dirichlet boundaries for the velocity"
return []
def velocity_initial_condition(self):
"Return initial condition for velocity"
return None
def pressure_initial_condition(self):
"Return initial condition for pressure"
return 0
def end_time(self):
"Return end time"
return 1.0
def time_step(self):
"Return preferred time step"
return None
def max_velocity(self):
"Return maximum velocity (used for selecting time step)"
return 1.0
def __str__(self):
"Return a short description of the problem"
return "Navier-Stokes problem"
