"""
Solver-specific boundary conditions. Here, in particular, we
implement a "moving-lid" option, i.e. fixed tangential velocity at a wall.
"""
from pyro.util import msg
[docs]
def user(bc_name, bc_edge, variable, ccdata):
"""
A moving lid boundary. This fixes the tangent velocity at the boundary
to 1, and the y-velocity to 0.
Parameters
----------
bc_name : {'moving_lid'}
The descriptive name for the boundary condition -- this allows
for pyro to have multiple types of user-supplied boundary
conditions. For this module, it needs to be 'moving_lid'.
bc_edge : {'ylb', 'yrb', 'xlb', 'xrb}
The boundary to update: ylb = lower y; yrb = upper y.
xlb = left x; xrb = right x
ccdata : CellCenterData2d object
The data object
"""
myg = ccdata.grid
if bc_name == "moving_lid":
if bc_edge == "yrb":
if variable in ("x-velocity", "u"):
v = ccdata.get_var(variable)
for j in range(myg.jhi+1, myg.jhi+myg.ng+1):
v[:, j] = 1.0 # unit velocity
elif variable in ("y-velocity", "v"):
v = ccdata.get_var(variable)
for j in range(myg.jhi+1, myg.jhi+myg.ng+1):
v[:, j] = 0.0
else:
raise NotImplementedError("variable not defined")
else:
msg.fail("error: moving_lid BC only implemented for 'yrb' (top boundary)")
else:
msg.fail(f"error: bc type {bc_name} not supported")