def points0():
# see Ludtke pg. 173 for values.
fluid = dict(
n2=0.0318,
co2=0.0118,
methane=0.8737,
ethane=0.0545,
propane=0.0178,
ibutane=0.0032,
nbutane=0.0045,
ipentane=0.0011,
npentane=0.0009,
nhexane=0.0007,
)
suc = State.define(p=Q_(62.7, "bar"), T=Q_(31.2, "degC"), fluid=fluid)
disch = State.define(p=Q_(76.82, "bar"), T=Q_(48.2, "degC"), fluid=fluid)
disch1 = State.define(p=Q_(76.0, "bar"), T=Q_(48.0, "degC"), fluid=fluid)
p0 = Point(
suc=suc,
disch=disch,
flow_m=85.9,
speed=Q_(13971, "RPM"),
b=Q_(44.2, "mm"),
D=0.318,
)
p1 = Point(
suc=suc,
disch=disch1,
flow_m=86.9,
speed=Q_(13971, "RPM"),
b=Q_(44.2, "mm"),
D=0.318,
)
return p0, p1
def load(cls, file_name):
with open(file_name) as f:
parameters = toml.load(f)
return cls([
Point(**Point._dict_from_load(kwargs))
for kwargs in parameters.values()
])
def point(self, flow_v=None, flow_m=None, speed=None):
"""Calculate specific point in the performance map.
Given a volumetric flow and a speed this method will calculate a point in the
impeller map according to these arguments.
Parameters
----------
flow_v : pint.Quantity, float
Volumetric flow (m³/s).
flow_m : pint.Quantity, float
Mass flow (kg/s).
speed : pint.Quantity, float
Speed (rad/s).
Returns
-------
point : ccp.Point
Point in the performance map.
"""
current_curve = self.curve(speed)
if flow_m:
flow_v = current_curve.points[0].suc.v() * flow_m
func_T = interp1d(current_curve.flow_v.m,
current_curve.disch.T().m,
fill_value="extrapolate")
func_p = interp1d(current_curve.flow_v.m,
current_curve.disch.p().m,
fill_value="extrapolate")
min_flow_v = min(current_curve.flow_v)
max_flow_v = max(current_curve.flow_v)
if flow_v < min_flow_v or max_flow_v < flow_v:
warnings.warn(
f"Expected point is being extrapolated.\n"
f"Interpolation limits: {min_flow_v:.3f~P} ~ {max_flow_v:.3f~P}\n"
f"Expected point flow: {flow_v:.3f~P}")
disch_T = func_T(flow_v)
disch_p = func_p(flow_v)
p0 = self.points[0]
disch = State.define(p=disch_p, T=disch_T, fluid=p0.suc.fluid)
point = Point(suc=p0.suc,
disch=disch,
flow_v=flow_v,
speed=speed,
b=p0.b,
D=p0.D)
return point
def imp1():
fluid = dict(
methane=0.69945,
ethane=0.09729,
propane=0.0557,
nbutane=0.0178,
ibutane=0.0102,
npentane=0.0039,
ipentane=0.0036,
nhexane=0.0018,
n2=0.0149,
co2=0.09259,
h2s=0.00017,
water=0.002,
)
suc = State.define(p=Q_(1.6995, "MPa"), T=311.55, fluid=fluid)
p0 = Point(
suc=suc,
flow_v=Q_(6501.67, "m**3/h"),
speed=Q_(11145, "RPM"),
head=Q_(179.275, "kJ/kg"),
eff=0.826357,
b=Q_(28.5, "mm"),
D=Q_(365, "mm"),
)
p1 = Point(
suc=suc,
flow_v=Q_(7016.72, "m**3/h"),
speed=Q_(11145, "RPM"),
head=Q_(173.057, "kJ/kg"),
eff=0.834625,
b=Q_(28.5, "mm"),
D=Q_(365, "mm"),
)
imp1 = Impeller([p0, p1])
return imp1
def load(cls, file):
"""Load impeller from toml file.
Parameters
----------
file : str or pathlib.Path
Filename to which the data is saved.
Returns
-------
impeller : ccp.Impeller
Impeller object.
"""
parameters = toml.load(file)
points = [
Point(**Point._dict_from_load(kwargs))
for kwargs in parameters.values()
]
return cls(points)
def imp2():
points = [
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1263 rad/s"),
flow_v=Q_("1.15 m³/s"),
head=Q_("147634 J/kg"),
eff=Q_("0.819"),
b=0.010745,
D=0.32560,
),
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1263 rad/s"),
flow_v=Q_("1.26 m³/s"),
head=Q_("144664 J/kg"),
eff=Q_("0.829"),
b=0.010745,
D=0.32560,
),
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1263 rad/s"),
flow_v=Q_("1.36 m³/s"),
head=Q_("139945 J/kg"),
eff=Q_("0.831"),
b=0.010745,
D=0.32560,
),
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1337 rad/s"),
flow_v=Q_("1.22 m³/s"),
head=Q_("166686 J/kg"),
eff=Q_("0.814"),
b=0.010745,
D=0.32560,
),
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1337 rad/s"),
flow_v=Q_("1.35 m³/s"),
head=Q_("163620 J/kg"),
eff=Q_("0.825"),
b=0.010745,
D=0.32560,
),
Point(
suc=State.define(p=Q_("100663 Pa"), T=Q_("305 K"), fluid={"AIR": 1.00000}),
speed=Q_("1337 rad/s"),
flow_v=Q_("1.48 m³/s"),
head=Q_("158536 J/kg"),
eff=Q_("0.830"),
b=0.010745,
D=0.32560,
),
]
imp2 = Impeller(points)
return imp2
def create_points_parallel(x):
"""Helper function used to parallelize creation of points."""
return Point(**x)
def curve(self, speed=None):
"""Calculate specific point in the performance map.
Given a speed this method will calculate a curve in the
impeller map according to these arguments.
Parameters
----------
speed : pint.Quantity, float
Speed (rad/s).
Returns
-------
curve : ccp.Curve
Point in the performance map.
"""
speeds = np.array([curve.speed.magnitude for curve in self.curves])
closest_curves_idxs = find_closest_speeds(speeds, speed.magnitude)
curves = [
self.curves[closest_curves_idxs[0]],
self.curves[closest_curves_idxs[1]],
]
# calculate factor
speed_range = curves[1].speed.magnitude - curves[0].speed.magnitude
factor = (speed.magnitude - curves[0].speed.magnitude) / speed_range
current_curve = []
p0 = self.points[0]
number_of_points = len(curves[0])
for i in range(number_of_points):
flow_T, disch_T = get_interpolated_values(
factor,
curves[0].flow_v.magnitude[i],
curves[0][i].disch.T().m,
curves[1].flow_v.magnitude[i],
curves[1][i].disch.T().m,
)
flow_p, disch_p = get_interpolated_values(
factor,
curves[0].flow_v.magnitude[i],
curves[0][i].disch.p().m,
curves[1].flow_v.magnitude[i],
curves[1][i].disch.p().m,
)
disch = State.define(p=disch_p, T=disch_T, fluid=p0.suc.fluid)
p = Point(
suc=p0.suc,
disch=disch,
flow_v=(flow_T + flow_p) / 2,
speed=speed,
b=p0.b,
D=p0.D,
)
current_curve.append(p)
current_curve = Curve(current_curve)
return current_curve