我查看了组成 FEniCS 的 julia 代码,fenics 页面上的周期性边界条件示例,以及我用于 fenics 的一些旧 python 代码,它启发了我写这个:
using FEniCS
using PyCall
@pyimport fenics
py"""
from dolfin import *
from mshr import *
length=2.2
height=0.41
channel = Rectangle(Point([0.0, 0.0]), Point([length, height]))
domain = channel
mesh = generate_mesh(domain, 64)
subdomains = MeshFunction("size_t", mesh, 1)
subdomains.set_all(0)
class Wall(SubDomain):
def inside(self,x,on_boundary):
return (near(x[1],height) or near(x[1],height)) and on_boundary
wall=Wall()
class PeriodicBoundary(SubDomain):
# Left boundary is "target domain" G
def inside(self, x, on_boundary):
return bool(x[0] < DOLFIN_EPS and x[0] > -DOLFIN_EPS and on_boundary)
# Map right boundary (H) to left boundary (G)
def map(self, x, y):
y[0] = x[0] - length
y[1] = x[1]
pbc=PeriodicBoundary()
"""
Q=FunctionSpace(fenics.VectorFunctionSpace(py"mesh", "P", 1,constrained_domain=py"pbc"))
该解决方案不是最佳的,因为它只是在 python 中完成了整个事情,但我认为我将不得不忍受它。