single_periodic_porous.py 文件源码

def create_bcs(Lx, Ly, mesh, grid_spacing, rad, num_obstacles,
               surface_charge, solutes, enable_NS, enable_EC,
               p_lagrange, V_lagrange,
               **namespace):
    """ The boundaries and boundary conditions are defined here. """
    data = np.loadtxt(
        "meshes/periodic_porous_Lx{}_Ly{}_rad{}_N{}_dx{}.dat".format(
            Lx, Ly, rad, num_obstacles, grid_spacing))
    centroids = data[:, :2]
    rad = data[:, 2]

    # Find a single node to pin pressure to
    x_loc = np.array(mesh.coordinates())
    x_proc = np.zeros((size, 2))
    ids_notboun = np.logical_and(
        x_loc[:, 0] > x_loc[:, 0].min() + df.DOLFIN_EPS,
        x_loc[:, 1] > x_loc[:, 1].min() + df.DOLFIN_EPS)
    x_loc = x_loc[ids_notboun, :]
    d2 = (x_loc[:, 0]+Lx/2)**2 + (x_loc[:, 1]+Ly/2)**2
    x_bottomleft = x_loc[d2 == d2.min()][0]
    x_proc[rank, :] = x_bottomleft
    x_pin = np.zeros_like(x_proc)
    comm.Allreduce(x_proc, x_pin, op=MPI.SUM)
    x_pin = x_pin[x_pin[:, 0] == x_pin[:, 0].min(), :][0]

    info("Pinning point: {}".format(x_pin))

    pin_code = ("x[0] < {x}+{eps} && "
                "x[0] > {x}-{eps} && "
                "x[1] > {y}-{eps} && "
                "x[1] < {y}+{eps}").format(
                    x=x_pin[0], y=x_pin[1], eps=1e-3)

    boundaries = dict(
        obstacles=[Obstacles(Lx, centroids, rad, grid_spacing)]
    )

    # Allocating the boundary dicts
    bcs = dict()
    bcs_pointwise = dict()
    for boundary in boundaries:
        bcs[boundary] = dict()

    noslip = Fixed((0., 0.))

    if enable_NS:
        bcs["obstacles"]["u"] = noslip

        if not p_lagrange:
            bcs_pointwise["p"] = (0., pin_code)

    if enable_EC:
        bcs["obstacles"]["V"] = Charged(surface_charge)

        if not V_lagrange:
            bcs_pointwise["V"] = (0., pin_code)

    return boundaries, bcs, bcs_pointwise