def test_stokes_terminal_velocity():
"""Test stokes terminal"""
bndc = IO.BoundaryData('particle_model/tests/data/boundary_circle.vtu')
system = System.System(bndc, base_name='particle_model/tests/data/circle',
gravity=numpy.array((0.0, -1.0, 0.0)),
rho=0.0, viscosity=1.0)
diameter = 1e-3
delta_t = 1.0e-8
par = ParticleBase.PhysicalParticle(diameter=diameter,
drag=DragModels.stokes_drag,
rho=1.0)
pos = numpy.zeros((1, 3))
vel = numpy.zeros((1, 3))
bucket = Particles.ParticleBucket(pos, vel, 0.0, delta_t=delta_t,
parameters=par,
system=system)
bucket.run(100*delta_t, write=False, method="RungeKutta4")
assert abs(bucket.time - 100*delta_t) < 1.0e-8
assert all(abs(bucket.particles[0].vel
- numpy.array((0,
-1.0/18./system.viscosity*par.diameter**2,
0))) < 1.e-8)
def test_gyre_collision():
"""Regression test for Mclaury coefficient"""
bndg = IO.BoundaryData('particle_model/tests/data/gyre_boundary.vtu')
system = System.System(bndg, coeff=1.0,
temporal_cache=temp_cache('gyre_0.vtu'))
from math import pi
pos = numpy.array((0.8, 0.45, 0.0))
vel = numpy.array((2.0 * pi, 0.0, 0.0))
part = Particles.Particle((pos, vel), delta_t=0.001, parameters=PAR1,
system=system)
for i in range(100):
del i
part.update(method="AdamsBashforth2")
assert part.pos[0] < 1.0
assert part.pos[1] < 1.0
assert part.pos[0] > 0.0
assert part.pos[1] > 0.0
assert len(part.collisions) == 1
assert part.collisions[0].pos[0] == 1.0
assert abs(Collision.mclaury_mass_coeff(part.collisions[0]) - 16.444037345317486) < 1.0e-8
def test_picker_linear_3d(tmpdir):
"""Test vtk picker in 3D."""
pos = ((0.5, 0.5, 0.5),
(0.25, 0.75, 0.25))
err = numpy.array((1.0e-8, 1.0e-8, 1.0e-8))
fname = tmpdir.join('linear3D.vtu').strpath
print(fname)
def vel(pos):
""" Fluid velocity"""
return numpy.array((pos[0], pos[1], pos[2]))
def pres(pos):
""" Fluid pressure"""
return pos[0]
IO.make_unstructured_grid(MESH3D, vel, pres, 0.0, fname)
system = System.System(temporal_cache=temp_cache('linear3D.vtu',
tmpdir.strpath))
part = Particles.Particle((0, 0), system=system)
for point in pos:
fluid_velocity, grad_p = part.picker(point, 0.0)
assert all(abs(fluid_velocity - vel(point)) < err)
assert all(grad_p == numpy.array((1.0, 0.0, 0.0)))
def test_polydata(tmpdir):
""" Test the polydata class """
from numpy import zeros
num = 100
pres = zeros((num, 3))
vel = zeros((num, 3))
fields = {"Test": zeros((num, 1))}
part = Particles.ParticleBucket(pres, vel, field_data=fields)
filepath = tmpdir.join('test.vtp').strpath
poly_data = IO.PolyData(tmpdir.join('test.vtp').strpath)
assert poly_data
poly_data.append_data(part)
assert len(poly_data.cell_ids) == num
assert poly_data.pnts.GetNumberOfPoints() == num
poly_data.write()
assert os.path.isfile(filepath)
assert poly_data.poly_data.GetNumberOfCells() == num
poly_data.append_data(part)
assert len(poly_data.cell_ids) == num
assert poly_data.pnts.GetNumberOfPoints() == 2 * num
def test_picker_constant():
"""Test vtk picker."""
part = Particles.Particle((0, 0), system=SYSTEM)
fluid_velocity, grad_p = part.picker((0.5, 0.5, 0.0), 0.0)
assert all(fluid_velocity == numpy.array((1.0, 0.0, 0.0)))
assert all(grad_p == numpy.array((0.0, 0.0, 0.0)))
def test_basic_particle_bucket_initialization():
""" Test initializing a particle bucket."""
from numpy import zeros
num = 10
pres = zeros((num, 3))
vel = zeros((num, 3))
part = Particles.ParticleBucket(pres, vel)
assert part
def test_step_spin_up_transitional_drag():
""" Test transitional drag function."""
pos = numpy.array((0.1, 0.5, 0.0))
vel = numpy.array((0.0, 0.0, 0.0))
phys_par = ParticleBase.PhysicalParticle(drag=DragModels.transitional_drag,
rho=1.0e3)
part = Particles.Particle((pos, vel), delta_t=0.001,
system=SYSTEM,
parameters=phys_par)
part.update(method="RungeKutta4")
assert all(abs(part.pos - numpy.array((0.10373956, 0.5, 0))) < 1.e-8)
assert part.time == 0.001
def test_step_constant_velocity():
"""Test single step at constant velocity."""
for method in Timestepping.methods:
pos = numpy.array((0.5, 0.5, 0.0))
vel = numpy.array((1.0, 0.0, 0.0))
part = Particles.Particle((pos, vel), delta_t=0.1, parameters=PAR0,
system=SYSTEM)
print(method)
part.update(method=method)
assert all(part.pos == numpy.array((0.6, 0.5, 0.0)))
assert part.time == 0.1
part.update()
assert all(part.pos == numpy.array((0.7, 0.5, 0.0)))
def test_diagonal_collision_3D():
"""Test a collision at an angle"""
pos = numpy.array((0.9995, 0.4995, 0.4995))
vel = numpy.array((1.0, 1.0, 1.0))
part = Particles.Particle((pos, vel), delta_t=0.001, parameters=PAR0,
system=SYSTEM3D)
part.update()
assert all(abs(part.pos - numpy.array((0.9995, 0.5005, 0.5005))) < 1.0e-8)
assert all(part.vel == numpy.array((-1., 1.0, 1.0)))
assert part.time == 0.001
assert len(part.collisions) == 1
assert all(part.collisions[0].pos - numpy.array((1., 0.5, 0.5)) < 1.0e-8)
assert part.collisions[0].time - 0.0005 < 1e-8
assert all(part.collisions[0].vel == numpy.array((1., 1., 1.)))
assert part.collisions[0].angle - numpy.pi / 4.0 < 1e-10
def test_step_head_on_collision():
""" Test a head-on collision."""
pos = numpy.array((0.9995, 0.5, 0.0))
vel = numpy.array((1.0, 0.0, 0.0))
part = Particles.Particle((pos, vel), delta_t=0.001, parameters=PAR0,
system=SYSTEM)
part.update(method="ForwardEuler")
assert all(abs(part.pos - numpy.array((0.9995, 0.5, 0.0))) < 1.0e-8)
assert all(part.vel == numpy.array((-1., 0., 0.)))
assert part.time == 0.001
assert len(part.collisions) == 1
assert all(part.collisions[0].pos == numpy.array((1., 0.5, 0.)))
assert part.collisions[0].time == 0.0005
assert all(part.collisions[0].vel == numpy.array((1., 0., 0.)))
assert part.collisions[0].angle == numpy.pi/2.0
def test_particle_bucket_step_do_nothing():
""" Test initializing a full particle bucket."""
from numpy import zeros
bndc = IO.BoundaryData('particle_model/tests/data/boundary_circle.vtu')
system = System.System(bndc, base_name='particle_model/tests/data/circle')
num = 1
pres = zeros((num, 3))
vel = zeros((num, 3))
bucket = Particles.ParticleBucket(pres, vel, 0.0, delta_t=0.5,
system=system)
bucket.run(5.0, write=False)
assert bucket.time == 5.0
assert all(bucket.particles[0].pos == 0.0)
assert all(bucket.particles[0].vel == 0.0)
def test_coefficient_of_restitution():
"""Test of coefficient of restitution parameter."""
pos = numpy.array((0.95, 0.5, 0.0))
vel = numpy.array((1.0, 0.0, 0.0))
system = System.System(BOUNDARY, coeff=0.5, temporal_cache=temp_cache())
part = Particles.Particle((pos, vel), delta_t=0.1, parameters=PAR0,
system=system)
part.update()
assert all(abs(part.pos-numpy.array((0.975, 0.5, 0))) < 1.0e-8)
assert all(part.vel == numpy.array((-0.5, 0, 0)))
assert part.time == 0.1
assert len(part.collisions) == 1
assert all(part.collisions[0].pos == numpy.array((1., 0.5, 0.)))
assert part.collisions[0].time == 0.05
assert all(part.collisions[0].vel == numpy.array((1., 0., 0.)))
assert part.collisions[0].angle == numpy.pi/2.0