def test_odd_axial_symmetry():
"""Buoy with odd number of slices."""
def shape(z):
return 0.1 * (-(z + 1)**2 + 16)
buoy = FloatingBody(
AxialSymmetricMesh.from_profile(shape,
z_range=np.linspace(-5.0, 0.0, 9),
nphi=5))
buoy.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=buoy, omega=2.0)
result1 = solver_with_sym.solve(problem)
full_buoy = FloatingBody(buoy.mesh.merged())
full_buoy.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=full_buoy, omega=2.0)
result2 = solver_with_sym.solve(problem)
volume = buoy.mesh.volume
assert np.isclose(result1.added_masses["Heave"],
result2.added_masses["Heave"],
atol=1e-4 * volume * problem.rho)
assert np.isclose(result1.radiation_dampings["Heave"],
result2.radiation_dampings["Heave"],
atol=1e-4 * volume * problem.rho)
def test_dof():
nodes = np.array([[0, 0, 0], [0, 0, 1], [1, 0, 1], [1, 0, 0]])
faces = np.array([[0, 1, 2, 3]])
body = FloatingBody(Mesh(nodes, faces), name="one_face")
assert body.dofs == {}
body.add_translation_dof(direction=(1.0, 0.0, 0.0), name="1")
assert np.allclose(body.dofs["1"], np.array([1.0, 0.0, 0.0]))
body.add_translation_dof(direction=(0.0, 1.0, 0.0), name="2")
assert np.allclose(body.dofs["2"], np.array([0.0, 1.0, 0.0]))
body.add_rotation_dof(Axis(vector=(0.0, 0.0, 1.0)), name="3")
body.add_rotation_dof(Axis(point=(0.5, 0, 0), vector=(0.0, 0.0, 1.0)), name="4")
def test_floating_sphere(depth, omega):
"""Comparison of the added mass and radiation damping
for a heaving sphere described using several symmetries
in finite and infinite depth.
"""
reso = 2
full_sphere = Sphere(radius=1.0, ntheta=reso, nphi=4*reso, axial_symmetry=False, clip_free_surface=True)
full_sphere.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=full_sphere, omega=omega, sea_bottom=-depth)
result1 = solver_with_sym.solve(problem)
half_sphere_mesh = full_sphere.mesh.extract_faces(
np.where(full_sphere.mesh.faces_centers[:, 1] > 0)[0],
name="half_sphere_mesh")
two_halves_sphere = FloatingBody(ReflectionSymmetricMesh(half_sphere_mesh, xOz_Plane))
two_halves_sphere.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=two_halves_sphere, omega=omega, sea_bottom=-depth)
result2 = solver_with_sym.solve(problem)
quarter_sphere_mesh = half_sphere_mesh.extract_faces(
np.where(half_sphere_mesh.faces_centers[:, 0] > 0)[0],
name="quarter_sphere_mesh")
four_quarter_sphere = FloatingBody(ReflectionSymmetricMesh(ReflectionSymmetricMesh(quarter_sphere_mesh, yOz_Plane), xOz_Plane))
assert 'None' not in four_quarter_sphere.mesh.tree_view()
four_quarter_sphere.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=four_quarter_sphere, omega=omega, sea_bottom=-depth)
result3 = solver_with_sym.solve(problem)
clever_sphere = Sphere(radius=1.0, ntheta=reso, nphi=4*reso, axial_symmetry=True, clip_free_surface=True)
clever_sphere.add_translation_dof(direction=(0, 0, 1), name="Heave")
problem = RadiationProblem(body=clever_sphere, omega=omega, sea_bottom=-depth)
result4 = solver_with_sym.solve(problem)
# (quarter_sphere + half_sphere + full_sphere + clever_sphere).show()
volume = 4/3*np.pi
assert np.isclose(result1.added_masses["Heave"], result2.added_masses["Heave"], atol=1e-4*volume*problem.rho)
assert np.isclose(result1.added_masses["Heave"], result3.added_masses["Heave"], atol=1e-4*volume*problem.rho)
assert np.isclose(result1.added_masses["Heave"], result4.added_masses["Heave"], atol=1e-4*volume*problem.rho)
assert np.isclose(result1.radiation_dampings["Heave"], result2.radiation_dampings["Heave"], atol=1e-4*volume*problem.rho)
assert np.isclose(result1.radiation_dampings["Heave"], result3.radiation_dampings["Heave"], atol=1e-4*volume*problem.rho)
assert np.isclose(result1.radiation_dampings["Heave"], result4.radiation_dampings["Heave"], atol=1e-4*volume*problem.rho)