def fluid_flow_long_numerical():
nz = 8
ntheta = 32
nradius = 8
omega = 100.0 * 2 * np.pi / 60
p_in = 0.0
p_out = 0.0
radius_rotor = 1
h = 0.000194564
radius_stator = radius_rotor + h
length = 8 * 2 * radius_stator
visc = 0.015
rho = 860.0
eccentricity = 0.0001
return flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
immediately_calculate_pressure_matrix_numerically=False,
)
def fluid_flow_short_eccentricity():
nz = 8
ntheta = 32
nradius = 8
omega = 100.0 * 2 * np.pi / 60
p_in = 0.0
p_out = 0.0
radius_rotor = 0.1999996
radius_stator = 0.1999996 + 0.000194564
length = (1 / 10) * (2 * radius_stator)
eccentricity = 0.0001
visc = 0.015
rho = 860.0
return flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
immediately_calculate_pressure_matrix_numerically=False,
)
def fluid_flow_long_numerical():
nz = 8
ntheta = 132
nradius = 11
omega = 100. * 2 * np.pi / 60
p_in = 0.
p_out = 0.
radius_rotor = 1
h = 0.000194564
radius_stator = radius_rotor + h
length = 8 * 2 * radius_stator
visc = 0.015
rho = 860.
eccentricity = 0.0001
return flow.FluidFlow(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity)
def fluid_flow_short_numerical():
nz = 8
ntheta = 32
nradius = 8
length = 0.01
omega = 100.0 * 2 * np.pi / 60
p_in = 0.0
p_out = 0.0
radius_rotor = 0.08
radius_stator = 0.1
visc = 0.015
rho = 860.0
attitude_angle = None
eccentricity = 0.001
return flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
attitude_angle=attitude_angle,
eccentricity=eccentricity,
immediately_calculate_pressure_matrix_numerically=False,
)
def fluid_flow_short_numerical():
nz = 8
ntheta = 132
nradius = 11
length = 0.01
omega = 100. * 2 * np.pi / 60
p_in = 0.
p_out = 0.
radius_rotor = 0.08
radius_stator = 0.1
visc = 0.015
rho = 860.
attitude_angle = None
eccentricity = 0.001
return flow.FluidFlow(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
attitude_angle=attitude_angle,
eccentricity=eccentricity)
def fluid_flow_short_eccentricity():
nz = 16
ntheta = 528
nradius = 11
omega = 100. * 2 * np.pi / 60
p_in = 0.
p_out = 0.
radius_rotor = 0.1999996
radius_stator = 0.1999996 + 0.000194564
length = (1 / 10) * (2 * radius_stator)
eccentricity = 0.0001
visc = 0.015
rho = 860.
return flow.FluidFlow(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity)
def fluid_flow_short_friswell(set_load=True):
nz = 8
ntheta = 32
nradius = 8
length = 0.03
omega = 157.1
p_in = 0.0
p_out = 0.0
radius_rotor = 0.0499
radius_stator = 0.05
load = 525
visc = 0.1
rho = 860.0
eccentricity = (radius_stator - radius_rotor) * 0.2663
if set_load:
return flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
load=load,
immediately_calculate_pressure_matrix_numerically=False,
)
else:
return flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
immediately_calculate_pressure_matrix_numerically=False,
)
def fluid_flow_short_friswell(set_load=True):
nz = 30
ntheta = 20
nradius = 11
length = 0.03
omega = 157.1
p_in = 0.
p_out = 0.
radius_rotor = 0.0499
radius_stator = 0.05
load = 525
visc = 0.1
rho = 860.
eccentricity = (radius_stator - radius_rotor) * 0.2663
if set_load:
return flow.FluidFlow(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
load=load)
else:
return flow.FluidFlow(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity)
def fluid_flow_example3():
"""This function returns a different instance of a simple fluid flow.
The purpose is to make available a simple model
so that doctest can be written using it.
Parameters
----------
Returns
-------
An instance of a fluid flow object.
Examples
--------
>>> my_fluid_flow = fluid_flow_example3()
>>> my_fluid_flow.eccentricity
0.0001
"""
from ross.fluid_flow import fluid_flow as flow
nz = 8
ntheta = 32 * 4
omega = 100.0 * 2 * np.pi / 60
p_in = 0.0
p_out = 0.0
radius_rotor = 1
h = 0.000194564
radius_stator = radius_rotor + h
length = 8 * 2 * radius_stator
visc = 0.015
rho = 860.0
eccentricity = 1e-4
attitude_angle = np.pi / 4
return flow.FluidFlow(
nz,
ntheta,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
attitude_angle=attitude_angle,
immediately_calculate_pressure_matrix_numerically=False,
)
def instantiate_fluid_flow_object(number_of_theta_nodes, number_of_z_nodes,
length_type):
"""Instantiates a FluidFlow object, either short or long, using the same parameters in ROSS tests.
Parameters
----------
number_of_theta_nodes: int
number_of_z_nodes: int
length_type: bool
Defines if short (True) or long (False) bearing.
Returns
-------
A FluidFlow object
"""
nradius = 11
omega = 100.0 * 2 * np.pi / 60
p_in = 0.0
p_out = 0.0
eccentricity = 0.0001
visc = 0.015
rho = 860.0
if length_type:
radius_rotor = 0.1999996
radius_stator = 0.1999996 + 0.000194564
length = (1 / 10) * (2 * radius_stator)
else:
p_in = 1
p_out = 0
radius_rotor = 1
h = 0.000194564
radius_stator = radius_rotor + h
length = 8 * 2 * radius_stator
return flow.FluidFlow(
number_of_z_nodes,
number_of_theta_nodes,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
immediately_calculate_pressure_matrix_numerically=False)
def from_fluid_flow(
cls,
n,
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=None,
load=None,
):
"""Instantiate a bearing using inputs from its fluid flow.
Parameters
----------
n : int
The node in which the bearing will be located in the rotor.
Grid related
^^^^^^^^^^^^
Describes the discretization of the problem
nz: int
Number of points along the Z direction (direction of flow).
ntheta: int
Number of points along the direction theta. NOTE: ntheta must be odd.
nradius: int
Number of points along the direction r.
length: float
Length in the Z direction (m).
Operation conditions
^^^^^^^^^^^^^^^^^^^^
Describes the operation conditions.
omega: float
Rotation of the rotor (rad/s).
p_in: float
Input Pressure (Pa).
p_out: float
Output Pressure (Pa).
load: float
Load applied to the rotor (N).
Geometric data of the problem
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Describes the geometric data of the problem.
radius_rotor: float
Rotor radius (m).
radius_stator: float
Stator Radius (m).
eccentricity: float
Eccentricity (m) is the euclidean distance between rotor and stator centers.
The center of the stator is in position (0,0).
Fluid characteristics
^^^^^^^^^^^^^^^^^^^^^
Describes the fluid characteristics.
visc: float
Viscosity (Pa.s).
rho: float
Fluid density(Kg/m^3).
Returns
-------
bearing: rs.BearingElement
A bearing object.
Examples
--------
>>> nz = 30
>>> ntheta = 20
>>> nradius = 11
>>> length = 0.03
>>> omega = 157.1
>>> p_in = 0.
>>> p_out = 0.
>>> radius_rotor = 0.0499
>>> radius_stator = 0.05
>>> eccentricity = (radius_stator - radius_rotor)*0.2663
>>> visc = 0.1
>>> rho = 860.
>>> BearingElement.from_fluid_flow(0, nz, ntheta, nradius, length, omega, p_in,
... p_out, radius_rotor, radius_stator,
... visc, rho, eccentricity=eccentricity) # doctest: +ELLIPSIS
BearingElement(n=0, n_link=None,
kxx=[...
"""
fluid_flow = flow.FluidFlow(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
load=load,
)
c = calculate_damping_matrix(fluid_flow, force_type="short")
k = calculate_stiffness_matrix(fluid_flow, force_type="short")
return cls(
n,
kxx=k[0],
cxx=c[0],
kyy=k[3],
kxy=k[1],
kyx=k[2],
cyy=c[3],
cxy=c[1],
cyx=c[2],
frequency=fluid_flow.omega,
)
def from_fluid_flow(
cls,
n,
nz,
ntheta,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
viscosity,
density,
attitude_angle=None,
eccentricity=None,
load=None,
omegap=None,
immediately_calculate_pressure_matrix_numerically=True,
tag=None,
n_link=None,
scale_factor=1,
is_random=None,
):
"""Instantiate a bearing using inputs from its fluid flow.
Parameters
----------
n : int
The node in which the bearing will be located in the rotor.
is_random : list
List of the object attributes to become random.
Possibilities:
["length", "omega", "p_in", "p_out", "radius_rotor",
"radius_stator", "viscosity", "density", "attitude_angle",
"eccentricity", "load", "omegap"]
tag: str, optional
A tag to name the element
Default is None.
n_link: int, optional
Node to which the bearing will connect. If None the bearing is
connected to ground.
Default is None.
scale_factor: float, optional
The scale factor is used to scale the bearing drawing.
Default is 1.
Grid related
^^^^^^^^^^^^
Describes the discretization of the problem
nz: int
Number of points along the Z direction (direction of flow).
ntheta: int
Number of points along the direction theta. NOTE: ntheta must be odd.
nradius: int
Number of points along the direction r.
length: float, list
Length in the Z direction (m).
Input a list to make it random.
Operation conditions
^^^^^^^^^^^^^^^^^^^^
Describes the operation conditions.
omega: float, list
Rotation of the rotor (rad/s).
Input a list to make it random.
p_in: float, list
Input Pressure (Pa).
Input a list to make it random.
p_out: float, list
Output Pressure (Pa).
Input a list to make it random.
load: float, list
Load applied to the rotor (N).
Input a list to make it random.
Geometric data of the problem
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Describes the geometric data of the problem.
radius_rotor: float, list
Rotor radius (m).
Input a list to make it random.
radius_stator: float, list
Stator Radius (m).
Input a list to make it random.
eccentricity: float, list
Eccentricity (m) is the euclidean distance between rotor and stator
centers.
The center of the stator is in position (0,0).
Input a list to make it random.
Fluid characteristics
^^^^^^^^^^^^^^^^^^^^^
Describes the fluid characteristics.
viscosity: float, list
Viscosity (Pa.s).
Input a list to make it random.
density: float, list
Fluid density(Kg/m^3).
Input a list to make it random.
Returns
-------
random bearing: srs.ST_BearingElement
A random bearing object.
Examples
--------
>>> import numpy as np
>>> import ross.stochastic as srs
>>> nz = 8
>>> ntheta = 64
>>> length = 1.5 * 0.0254
>>> omega = [157.1, 300]
>>> p_in = 0.
>>> p_out = 0.
>>> radius_rotor = 3 * 0.0254
>>> radius_stator = 3.003 * 0.0254
>>> viscosity = np.random.uniform(2.4e-03, 2.8e-03, 5)
>>> density = 860
>>> load = 1244.1
>>> elms = srs.ST_BearingElement.from_fluid_flow(
... 0, nz=nz, ntheta=ntheta, length=length,
... omega=omega, p_in=p_in, p_out=p_out, radius_rotor=radius_rotor,
... radius_stator=radius_stator, viscosity=viscosity, density=density,
... load=load, is_random=["viscosity"]
... )
>>> len(list(iter(elms)))
5
"""
attribute_dict = locals()
attribute_dict.pop("cls")
attribute_dict.pop("omega")
attribute_dict.pop("is_random")
size = len(attribute_dict[is_random[0]])
args_dict = {
"kxx": np.zeros((len(omega), size)),
"kxy": np.zeros((len(omega), size)),
"kyx": np.zeros((len(omega), size)),
"kyy": np.zeros((len(omega), size)),
"cxx": np.zeros((len(omega), size)),
"cxy": np.zeros((len(omega), size)),
"cyx": np.zeros((len(omega), size)),
"cyy": np.zeros((len(omega), size)),
}
for k, v in attribute_dict.items():
if k not in is_random:
attribute_dict[k] = np.full(size, v)
else:
attribute_dict[k] = np.asarray(v)
for j, frequency in enumerate(omega):
for i in range(size):
fluid_flow = flow.FluidFlow(
attribute_dict["nz"][i],
attribute_dict["ntheta"][i],
attribute_dict["length"][i],
frequency,
attribute_dict["p_in"][i],
attribute_dict["p_out"][i],
attribute_dict["radius_rotor"][i],
attribute_dict["radius_stator"][i],
attribute_dict["viscosity"][i],
attribute_dict["density"][i],
attribute_dict["attitude_angle"][i],
attribute_dict["eccentricity"][i],
attribute_dict["load"][i],
attribute_dict["omegap"][i],
)
k, c = calculate_stiffness_and_damping_coefficients(fluid_flow)
args_dict["kxx"][j, i] = k[0]
args_dict["kxy"][j, i] = k[1]
args_dict["kyx"][j, i] = k[2]
args_dict["kyy"][j, i] = k[3]
args_dict["cxx"][j, i] = c[0]
args_dict["cxy"][j, i] = c[1]
args_dict["cyx"][j, i] = c[2]
args_dict["cyy"][j, i] = c[3]
return cls(
n,
kxx=args_dict["kxx"],
cxx=args_dict["cxx"],
kyy=args_dict["kyy"],
kxy=args_dict["kxy"],
kyx=args_dict["kyx"],
cyy=args_dict["cyy"],
cxy=args_dict["cxy"],
cyx=args_dict["cyx"],
frequency=omega,
tag=tag,
n_link=n_link,
scale_factor=scale_factor,
is_random=list(args_dict.keys()),
)
def from_fluid_flow(
cls,
n,
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=None,
load=None,
tag=None,
n_link=None,
scale_factor=1,
is_random=None,
):
"""Instantiate a bearing using inputs from its fluid flow.
Parameters
----------
n : int
The node in which the bearing will be located in the rotor.
is_random : list
List of the object attributes to become random.
Possibilities:
["length", "omega", "p_in", "p_out", "radius_rotor",
"radius_stator", "visc", "rho", "eccentricity", "load"]
tag: str, optional
A tag to name the element
Default is None.
n_link: int, optional
Node to which the bearing will connect. If None the bearing is
connected to ground.
Default is None.
scale_factor: float, optional
The scale factor is used to scale the bearing drawing.
Default is 1.
Grid related
^^^^^^^^^^^^
Describes the discretization of the problem
nz: int
Number of points along the Z direction (direction of flow).
ntheta: int
Number of points along the direction theta. NOTE: ntheta must be odd.
nradius: int
Number of points along the direction r.
length: float, list
Length in the Z direction (m).
Input a list to make it random.
Operation conditions
^^^^^^^^^^^^^^^^^^^^
Describes the operation conditions.
omega: float, list
Rotation of the rotor (rad/s).
Input a list to make it random.
p_in: float, list
Input Pressure (Pa).
Input a list to make it random.
p_out: float, list
Output Pressure (Pa).
Input a list to make it random.
load: float, list
Load applied to the rotor (N).
Input a list to make it random.
Geometric data of the problem
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Describes the geometric data of the problem.
radius_rotor: float, list
Rotor radius (m).
Input a list to make it random.
radius_stator: float, list
Stator Radius (m).
Input a list to make it random.
eccentricity: float, list
Eccentricity (m) is the euclidean distance between rotor and stator
centers.
The center of the stator is in position (0,0).
Input a list to make it random.
Fluid characteristics
^^^^^^^^^^^^^^^^^^^^^
Describes the fluid characteristics.
visc: float, list
Viscosity (Pa.s).
Input a list to make it random.
rho: float, list
Fluid density(Kg/m^3).
Input a list to make it random.
Returns
-------
random bearing: srs.ST_BearingElement
A random bearing object.
Examples
--------
>>> import numpy as np
>>> import ross.stochastic as srs
>>> nz = 30
>>> ntheta = 20
>>> nradius = 11
>>> length = 0.03
>>> omega = 157.1
>>> p_in = 0.
>>> p_out = 0.
>>> radius_rotor = 0.0499
>>> radius_stator = 0.05
>>> eccentricity = (radius_stator - radius_rotor)*0.2663
>>> visc = np.random.uniform(0.1, 0.2, 5)
>>> rho = 860.0
>>> elms = srs.ST_BearingElement.from_fluid_flow(
... 0, nz, ntheta, nradius, length,
... omega, p_in, p_out, radius_rotor,
... radius_stator, visc, rho,
... eccentricity=eccentricity, is_random=["visc"]
... )
>>> len(list(iter(elms)))
5
"""
attribute_dict = locals()
size = len(attribute_dict[is_random[0]])
args_dict = {
"kxx": [],
"kxy": [],
"kyx": [],
"kyy": [],
"cxx": [],
"cxy": [],
"cyx": [],
"cyy": [],
}
for k, v in attribute_dict.items():
if k not in is_random:
attribute_dict[k] = np.full(size, v)
else:
attribute_dict[k] = np.asarray(v)
for i in range(size):
fluid_flow = flow.FluidFlow(
attribute_dict["nz"][i],
attribute_dict["ntheta"][i],
attribute_dict["nradius"][i],
attribute_dict["length"][i],
attribute_dict["omega"][i],
attribute_dict["p_in"][i],
attribute_dict["p_out"][i],
attribute_dict["radius_rotor"][i],
attribute_dict["radius_stator"][i],
attribute_dict["visc"][i],
attribute_dict["rho"][i],
eccentricity=attribute_dict["eccentricity"][i],
load=attribute_dict["load"][i],
)
c = calculate_short_damping_matrix(fluid_flow)
k = calculate_short_stiffness_matrix(fluid_flow)
args_dict["kxx"].append(k[0])
args_dict["kxy"].append(k[1])
args_dict["kyx"].append(k[2])
args_dict["kyy"].append(k[3])
args_dict["cxx"].append(c[0])
args_dict["cxy"].append(c[1])
args_dict["cyx"].append(c[2])
args_dict["cyy"].append(c[3])
return cls(
n,
kxx=args_dict["kxx"],
cxx=args_dict["cxx"],
kyy=args_dict["kyy"],
kxy=args_dict["kxy"],
kyx=args_dict["kyx"],
cyy=args_dict["cyy"],
cxy=args_dict["cxy"],
cyx=args_dict["cyx"],
frequency=[fluid_flow.omega],
tag=tag,
n_link=n_link,
scale_factor=scale_factor,
is_random=list(args_dict.keys()),
)
