Example #1
0
def generate_inviscid(path_msh, parent_folder):
    single_nodes_X, single_nodes_Y, elements = extract_msh(path_msh)

    rs = np.sqrt(single_nodes_X**2 + single_nodes_Y**2)
    thetas = np.arctan2(single_nodes_Y, single_nodes_X)

    Ur, Utheta, p = [], [], []
    for r, theta in zip(rs, thetas):
        if r == 0:
            Ur.append(0)
            Utheta.append(0)
            p.append(0)
        else:
            Ur.append((1 - (0.5 / r)**2) * np.cos(theta))
            Utheta.append((1 + (0.5 / r)**2) * np.sin(theta))
            p.append(2 * (0.5 / r)**2 * np.cos(2 * theta) - (0.5 / r)**4)

    Ur = np.array(Ur)
    Utheta = np.array(Utheta)
    p = np.array(p)

    U = Ur * np.cos(thetas) - Utheta * np.sin(thetas)
    V = Ur * np.sin(thetas) - Utheta * np.cos(thetas)

    nodes_X, nodes_Y = np.array([]), np.array([])
    Us, Vs, ps = np.array([]), np.array([]), np.array([])

    Nt = 101
    times = np.linspace(0, 1, Nt)
    for t in times:
        nodes_X = np.vstack([nodes_X, single_nodes_X
                             ]) if nodes_X.size else single_nodes_X
        nodes_Y = np.vstack([nodes_Y, single_nodes_Y
                             ]) if nodes_Y.size else single_nodes_Y

        Us = np.vstack([Us, U]) if Us.size else U
        Vs = np.vstack([Vs, V]) if Vs.size else V
        ps = np.vstack([ps, p]) if ps.size else p

    Re, Ur = 1e+6, 0.

    flow = Flow()

    flow.Re, flow.Ur = Re, Ur

    flow.times = times
    flow.nodes_X, flow.nodes_Y = nodes_X, nodes_Y
    flow.Us, flow.Vs, flow.ps = Us, Vs, ps

    write_flow(flow, parent_folder + 'flows/potential')

    find_neighbors(elements)
    write_elements(elements, parent_folder + 'elements/potential')

    write_geometries(
        np.array([[
            5, 407, 404, 408, 405, 409, 406, 410, 6, 414, 411, 415, 412, 416,
            413, 417
        ]]), parent_folder + 'geometries/potential')
Example #2
0
def generate_periodic(path_msh, parent_folder):
    single_nodes_X, single_nodes_Y, elements = extract_msh(path_msh)

    d = np.max(single_nodes_Y) - np.min(single_nodes_Y)

    Nt = 101
    times = np.linspace(0, 1, Nt)

    period = 0.25
    w = 2 * np.pi / period

    # U = U0*cos(wt) with U0 = 1
    # Navier-Stokes, uniform:
    # rho dU/dt + 0 = - dp/dx with rho = 1
    # dp/dx = rhoU0*w*sin(wt)
    # p = p0 + rhoU0*w*sin(wt) with p0 = 0

    nodes_X, nodes_Y = np.array([]), np.array([])
    Us, Vs, ps = np.array([]), np.array([]), np.array([])

    for t in times:
        nodes_X = np.vstack([nodes_X, single_nodes_X
                             ]) if nodes_X.size else single_nodes_X
        nodes_Y = np.vstack([nodes_Y, single_nodes_Y
                             ]) if nodes_Y.size else single_nodes_Y

        U = 0 * nodes_X + np.cos(w * t)
        V = 0 * nodes_X
        p = 0 * nodes_X + w * np.sin(w * t)

        Us = np.vstack([Us, U]) if Us.size else U
        Vs = np.vstack([Vs, V]) if Vs.size else V
        ps = np.vstack([ps, p]) if ps.size else p

    Re, Ur = 1 * 1 * d / 1e-6, np.inf

    flow = Flow()

    flow.Re, flow.Ur = Re, Ur

    flow.times = times
    flow.nodes_X, flow.nodes_Y = nodes_X, nodes_Y
    flow.Us, flow.Vs, flow.ps = Us, Vs, ps

    write_flow(flow, parent_folder + 'flows/periodic')

    find_neighbors(elements)
    write_elements(elements, parent_folder + 'elements/periodic')

    write_geometries(np.array([]), parent_folder + 'geometries/periodic')
Example #3
0
def generate_poiseuille(path_msh, parent_folder):
    single_nodes_X, single_nodes_Y, elements = extract_msh(path_msh)

    d = np.max(single_nodes_Y) - np.min(single_nodes_Y)
    y_middle = np.min(single_nodes_Y) + d / 2

    n_nodes = len(single_nodes_X)

    mu = 1e-3
    p = 2 * mu * single_nodes_X

    U = d**2 / 4 - (single_nodes_Y - y_middle)**2
    V = np.zeros(n_nodes)

    nodes_X, nodes_Y = np.array([]), np.array([])
    Us, Vs, ps = np.array([]), np.array([]), np.array([])

    Nt = 101
    times = np.linspace(0, 1, Nt)
    for t in times:
        nodes_X = np.vstack([nodes_X, single_nodes_X
                             ]) if nodes_X.size else single_nodes_X
        nodes_Y = np.vstack([nodes_Y, single_nodes_Y
                             ]) if nodes_Y.size else single_nodes_Y

        Us = np.vstack([Us, U]) if Us.size else U
        Vs = np.vstack([Vs, V]) if Vs.size else V
        ps = np.vstack([ps, p]) if ps.size else p

    Re, Ur = 1e-3 * 1 * d / mu, np.inf  # Reynolds number and reduced velocity are not
    # defined in the Hagen-Poiseuille problem

    flow = Flow()

    flow.Re, flow.Ur = Re, Ur

    flow.times = times
    flow.nodes_X, flow.nodes_Y = nodes_X, nodes_Y
    flow.Us, flow.Vs, flow.ps = Us, Vs, ps

    write_flow(flow, parent_folder + 'flows/poiseuille')

    find_neighbors(elements)
    write_elements(elements, parent_folder + 'elements/poiseuille')

    write_geometries(np.array([]), parent_folder + 'geometries/poiseuille')