def fluid_flow_short_eccentricity():
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.
return flow.PressureMatrix(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity)
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 * radius_stator
visc = 0.015
rho = 860.
beta = np.pi
eccentricity = 0.0001
return flow.PressureMatrix(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
beta=beta,
eccentricity=eccentricity)
def fluid_flow_short_load():
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.
return flow.PressureMatrix(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
load=load)
def fluid_flow_numerical():
nz = 8
ntheta = 64
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.
beta = np.pi
eccentricity = 0.001
return flow.PressureMatrix(nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
beta=beta,
eccentricity=eccentricity)
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
-------
A bearing object.
"""
fluid_flow = flow.PressureMatrix(
nz,
ntheta,
nradius,
length,
omega,
p_in,
p_out,
radius_rotor,
radius_stator,
visc,
rho,
eccentricity=eccentricity,
load=load,
)
k = fluid_flow.get_analytical_damping_matrix()
c = fluid_flow.get_analytical_stiffness_matrix()
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],
w=fluid_flow.omega,
)
