def computeHeatExchange(self, fStateFilm = None):
if (fStateFilm is None):
fStateFilm = FluidState(self.fluidName)
fStateFilm.update_Tp(self.inletTemperature, self.inletPressure)
self.inletEnthalpy = fStateFilm.h
self.Pr = fStateFilm.Pr
self.cond = fStateFilm.cond
# Determining Nusselt number
if (self.Re <= 2.3e3):
# laminar flow
self.Nu = 3.66
elif (self.Re > 2.3e3 and self.Re < 1e4):
# transition
interpCoeff = (self.Re - 2.3e3) / (1e4 - 2.3e3)
Nu_low = 3.66
xi = (1.8 * 4 - 1.5)**(-2)
Nu_high = ((xi / 8.) * 1e4 * self.Pr) / (1 + 12.7 * math.sqrt(xi / 8.) * (self.Pr**(2 / 3.) - 1)) * \
(1 + (self.internalDiameter / self.length)**(2 / 3.))
self.Nu = interpCoeff * Nu_high + (1 - interpCoeff) * Nu_low
elif (self.Re >= 1e4): # and self.Re <= 1e6):
# turbulent flow
xi = (1.8 * math.log(self.Re, 10) - 1.5)**(-2)
self.Nu = ((xi / 8.) * self.Re * self.Pr) / (1 + 12.7 * math.sqrt(xi / 8.) * (self.Pr**(2 / 3.) - 1))
#elif (self.Re > 1e6):
# raise ValueError("Reynolds Number outside range of validity")
self.alpha = self.cond * self.Nu / self.internalDiameter
if (self.computationWithIteration == True):
LMTD = - (self.outletTemperature - self.inletTemperature) / \
math.log((self.TWall - self.inletTemperature) / \
(self.TWall - self.outletTemperature))
self.QDot = self.alpha * self.internalSurfaceArea * LMTD
else:
self.QDot = self.alpha * self.internalSurfaceArea * (self.inletTemperature - self.TWall)
self.outletEnthalpy = self.inletEnthalpy - (self.QDot / self.massFlowRate)
fStateOut = FluidState(self.fluidName)
fStateOut.update_ph(self.outletPressure, self.outletEnthalpy)
prevOutletTemperature = self.outletTemperature
self.outletTemperature = fStateOut.T
if ((self.outletTemperature - self.TWall)*(self.inletTemperature - self.TWall) < 0):
if (self.computationWithIteration == True):
self.outletTemperature = 0.5 * prevOutletTemperature + 0.5 * self.TWall
else:
self.outletTemperature = self.TWall
else:
if (self.computationWithIteration == True):
self.outletTemperature = 0.9 * prevOutletTemperature + 0.1 * self.outletTemperature
def testState():
s1 = FluidState('ParaHydrogen')
s1.update('P', 700e5, 'T', 288)
print("p={0}".format(s1.p()))
print("T={0}".format(s1.T()))
print("rho={0}".format(s1.rho()))
print("h={0}".format(s1.h()))
print("s={0}".format(s1.s()))
print("cp={0}".format(s1.cp()))
print("cv={0}".format(s1.cv()))
print("gamma={0}".format(s1.gamma()))
print("dpdt_v={0}".format(s1.dpdt_v()))
print("dpdv_t={0}".format(s1.dpdv_t()))
print("beta={0}".format(s1.beta()))
print("mu={0}".format(s1.mu()))
print("lambfa={0}".format(s1.cond()))
print("Pr={0}".format(s1.Pr()))
s2 = FluidState('ParaHydrogen')
s2.update_Tp(s1.T(), s1.p())
print("update_Tp rho={0}".format(s2.rho()))
s3 = FluidState('ParaHydrogen')
s3.update_Trho(s1.T(), s1.rho())
print("update_Trho p={0}".format(s3.p()))
s4 = FluidState('ParaHydrogen')
s4.update_prho(s1.p(), s1.rho())
print("update_prho T={0}".format(s4.T()))
s5 = FluidState('ParaHydrogen')
s5.update_ph(s1.p(), s1.h())
print("update_ph ={0}".format(s5.T()))
s6 = FluidState('ParaHydrogen')
s6.update_ps(s1.p(), s1.s())
print("update_ps T={0}".format(s6.T()))
s7 = FluidState('ParaHydrogen')
s7.update_pq(1e5, 0)
print("update_pq T={0}".format(s7.T()))
s8 = FluidState('ParaHydrogen')
s8.update_Tq(25, 0)
print("update_Tq p={0}".format(s8.p()))
print('--------------------')
print('Initialize state from fluid')
h2 = Fluid('ParaHydrogen')
s9 = FluidState(h2)
s9.update_Tp(s1.T(), s1.p())
print("rho={0}".format(s9.rho()))
def setLimits(self, pMin=None, pMax=None, hMin=None, hMax=None, TMax=None):
# Reference points
self.minLiquid = FluidState(self.fluid)
self.minVapor = FluidState(self.fluid)
self.critical = FluidState(self.fluid)
self.critical.update_Trho(self.fluid.critical['T'],
self.fluid.critical['rho'])
# For general use
fState = FluidState(self.fluid)
# Pressure range
if (pMin is None):
pMin = self.fluid.tripple['p'] * 1.05
if (pMin < 1e3):
pMin = 1e3
self.pMin = pMin
self.minLiquid.update_pq(self.pMin, 0)
self.minVapor.update_pq(self.pMin, 1)
if (pMax is None):
pMax = 3 * self.critical.p
self.pMax = pMax
# Enthalpy range
domeWidth = self.minVapor.h - self.minLiquid.h
if (hMin is None):
hMin = self.minLiquid.h
self.hMin = hMin
# Determining max enthalpy
if (TMax is None):
if (hMax is None):
# default max enthalpy
if (self.critical.h > self.minVapor.h):
hMax = self.critical.h + domeWidth
else:
hMax = self.minVapor.h + domeWidth
else:
fState.update_Tp(TMax, self.pMin)
hMax = fState.h
self.hMax = hMax
# Axes ranges
self.xMin = self.hMin
self.xMax = self.hMax
self.yMin = self.pMin
self.yMax = self.pMax
# Density range
fState.update_ph(self.pMin, self.hMax)
self.rhoMin = fState.rho
self.rhoMax = self.minLiquid.rho
# Temperature range
self.TMin = self.fluid.saturation_p(self.pMin)["TsatL"]
if (TMax is None):
fState.update_ph(self.pMin, self.hMax)
TMax = fState.T
self.TMax = TMax
# Entropy range
self.sMin = 1.01 * self.minLiquid.s
fState.update_ph(self.pMin, self.hMax)
self.sMax = fState.s
# Minor diagonal coeff
self.minDiagonalSlope = np.log10(
self.pMax / self.pMin) / (self.hMax - self.hMin) * 1e3
# Major diagonal coeff
self.majDiagonalSlope = -self.minDiagonalSlope
def setLimits(self, pMin = None, pMax = None, hMin = None, hMax = None, TMax = None): # Reference points self.minLiquid = FluidState(self.fluid) self.minVapor = FluidState(self.fluid) self.critical = FluidState(self.fluid) self.critical.update_Trho(self.fluid.critical['T'], self.fluid.critical['rho']) # For general use fState = FluidState(self.fluid) # Pressure range if (pMin is None): pMin = self.fluid.tripple['p'] * 1.05 if (pMin < 1e3): pMin = 1e3 self.pMin = pMin self.minLiquid.update_pq(self.pMin, 0) self.minVapor.update_pq(self.pMin, 1) if (pMax is None): pMax = 3 * self.critical.p self.pMax = pMax # Enthalpy range domeWidth = self.minVapor.h - self.minLiquid.h if (hMin is None): hMin = self.minLiquid.h self.hMin = hMin # Determining max enthalpy if (TMax is None): if (hMax is None): # default max enthalpy if (self.critical.h > self.minVapor.h): hMax = self.critical.h + domeWidth else: hMax = self.minVapor.h + domeWidth else: fState.update_Tp(TMax, self.pMin) hMax = fState.h self.hMax = hMax # Axes ranges self.xMin = self.hMin self.xMax = self.hMax self.yMin = self.pMin self.yMax = self.pMax # Density range fState.update_ph(self.pMin, self.hMax) self.rhoMin = fState.rho self.rhoMax = self.minLiquid.rho # Temperature range self.TMin = self.fluid.saturation_p(self.pMin)["TsatL"] if (TMax is None): fState.update_ph(self.pMin, self.hMax) TMax = fState.T self.TMax = TMax # Entropy range self.sMin = 1.01 * self.minLiquid.s fState.update_ph(self.pMin, self.hMax) self.sMax = fState.s # Minor diagonal coeff self.minDiagonalSlope = np.log10(self.pMax/self.pMin) / (self.hMax - self.hMin) * 1e3 # Major diagonal coeff self.majDiagonalSlope = - self.minDiagonalSlope
