def test_stratified_angle_array(self):
alphaL = np.array([0, 0.25, 0.5, 0.75, 1])
betha = np.array([0, 2.30988146, np.pi, 3.97330385, 2 * np.pi])
betha_calc = Geometry.stratified_angle(alphaL)
np.testing.assert_almost_equal(betha_calc, betha, decimal=1)
def model_closure(obj, t, qL, qG, alphaL, P):
D = obj.parameters['D']()
g = obj.parameters['g']()
epw = obj.parameters['epw']()
rhoL = obj.parameters['rhoL']()
muL = obj.parameters['muL']()
rhoG = obj.parameters['rhoG']()
muG = obj.parameters['muG']()
tetha = obj.parameters['tetha']()
alphaG = 1-alphaL
A = Geometry.area(D)
betha = Geometry.stratified_angle(alphaL)
#betha = 2 * np.pi * alphaL
hD = 0.5 * (1 - np.cos(0.5 * betha))
perL, perG, perI = Geometry.stratified_perimeters(D, betha)
vL = Hydraulics.velocity(qL, rhoL, alphaL*A)
vG = Hydraulics.velocity(qG, rhoG, alphaG*A)
DL = 4. * alphaL * A / perL
DG = 4. * alphaG * A / (perG + perI)
ReL = Dimensionless.reynolds(DL, vL, rhoL, muL)
ReG = Dimensionless.reynolds(DG, vG, rhoG, muG)
_, fDL = Hydraulics.ff_via_churchill(ReL, epw, DL)
_, fDG = Hydraulics.ff_via_churchill(ReG, epw, DG)
tauL = Hydraulics.shear_stress(fDL, rhoL, vL)
tauG = Hydraulics.shear_stress(fDG, rhoG, vG)
tauI = Hydraulics.shear_stress(fDG, rhoG, vG-vL)
zcml = D * (0.5 - 1 / 3 / np.pi / alphaL * np.sin(betha / 2) ** 3)
zcmg = D * (0.5 + 1 / 3 / np.pi / alphaG * np.sin(betha / 2) ** 3)
if qL.ndim == 2:
tetha = np.repeat(np.array([tetha]), qL.shape[1], axis=0).T
dPLG = ((rhoL - rhoG) * hD * D - rhoL * zcml + rhoG * zcmg) * g * np.cos(tetha)
dPL = alphaG * dPLG
dPG = -alphaL * dPLG
dPI = (alphaL * rhoL * (zcml - hD * D) + alphaG * rhoG * (zcmg - hD * D)) * g * np.cos(tetha)
return tauL*perL, tauG*perG, tauI*perI, dPL, dPG, dPI
def model_closure(obj, t, qL, qG, alphaL, P):
D = obj.parameters['D']()
g = obj.parameters['g']()
epw = obj.parameters['epw']()
rhoL = obj.parameters['rhoL']()
muL = obj.parameters['muL']()
rhoG = obj.parameters['rhoG']()
muG = obj.parameters['muG']()
tetha = obj.parameters['tetha']()
tension = obj.parameters['tension']()
alphaG = 1 - alphaL
A = Geometry.area(D)
vL = Hydraulics.velocity(qL, rhoL, alphaL * A)
vG = Hydraulics.velocity(qG, rhoG, alphaG * A)
vLS = Hydraulics.velocity(qL, rhoL, A)
vGS = Hydraulics.velocity(qG, rhoG, A)
vM = vGS + vLS
ReL = Dimensionless.reynolds(D, vL, rhoL, muL)
ReM = Dimensionless.reynolds(D, vM, rhoL, muL)
_, fDL = Hydraulics.ff_via_churchill(ReL, epw, D)
_, fDM = Hydraulics.ff_via_churchill(ReM, epw, D)
fDG = 0.0
dbmax = (0.725 + 4.15 * (vGS / vM)**0.5) * (tension / rhoL)**(
3 / 5) * (2 * fDM * vM**3 / D)**(-2 / 5)
db = (16. * tension / g / (rhoL - rhoG))**0.5
db = np.fmax(db, dbmax)
vb = (0.51 * db + 2.14 / db)**0.5
CDb = 4 / 3 * ((rhoL - rhoG) / rhoL) * g * db / (vb**2)
fDI = 1.5 * alphaG * rhoL * CDb / db
perL = np.pi * D * alphaL
perG = np.pi * D * alphaG
perI = np.pi * D**2 * alphaG / db
tauL = Hydraulics.shear_stress(fDL, rhoL, vL)
tauG = Hydraulics.shear_stress(fDG, rhoG, vG)
tauI = Hydraulics.shear_stress(fDI, rhoG, vG - vL)
dPL = 1 / 4. * rhoL * (vG - vL)**2
dPG = 0
dPI = 0
return tauL * perL, tauG * perG, tauI * perI, dPL, dPG, dPI
def residue(self, t: float, y: np.ndarray, yp: np.ndarray, par=None):
D = self.parameters['D']()
epw = self.parameters['epw']()
rho = self.parameters['rho']()
mu = self.parameters['mu']()
drhodP = self.parameters['drhodP']()
z = self.parameters['z']()
g = self.parameters['g']()
q_lb = self.parameters['q_lb'](t)
P_ub = self.parameters['P_ub'](t)
q = self.variables["q"].parse(y)
dqdt = self.variables["q"].parse(yp)
P = self.variables["P"].parse(y)
dPdt = self.variables["P"].parse(yp)
A = Geometry.area(D)
per = np.pi * D
v = Hydraulics.velocity(q, rho, A)
Re = Dimensionless.reynolds(D, v, rho, mu)
_, fD = Hydraulics.ff_via_churchill(Re, epw, D)
tau = Hydraulics.shear_stress(fD, rho, v)
res_1 = drhodP * dPdt + 1 / A * self.grad_x(q)
res_2 = dqdt + A * self.grad_x(P) + self.grad_x_hrs(
q * v, q) + tau * per + rho * g * A * self.grad_x(z)
eq1 = Equation(res_1, regions=(RegionEnum.OPEN_CLOSED, ))
eq2 = Equation(res_2, regions=(RegionEnum.CLOSED_OPEN, ))
bc1 = BoundaryCondition(q,
q_lb,
kind=BoundaryConditionEnum.DIRICHLET,
regions_1=(RegionEnum.LOWER, ))
bc2 = BoundaryCondition(P,
P_ub,
kind=BoundaryConditionEnum.DIRICHLET,
regions_1=(RegionEnum.UPPER, ))
eqs = Equations((eq1, eq2, bc1, bc2))
res = eqs()
ires = 0
return res, ires
def model_closure(obj, t, qL, qG, alphaL, P):
D = obj.parameters['D']()
g = obj.parameters['g']()
epw = obj.parameters['epw']()
rhoL = obj.parameters['rhoL']()
muL = obj.parameters['muL']()
rhoG = obj.parameters['rhoG']()
muG = obj.parameters['muG']()
alphaG = 1 - alphaL
A = Geometry.area(D)
perG = 0
perL = np.pi * D
perI = np.pi * D * alphaG**0.5
vL = Hydraulics.velocity(qL, rhoL, alphaL * A)
vG = Hydraulics.velocity(qG, rhoG, alphaG * A)
DL = 4. * alphaL * A / perL
DG = 4. * alphaG * A / (perG + perI)
ReL = Dimensionless.reynolds(DL, vL, rhoL, muL)
ReG = Dimensionless.reynolds(DG, vG, rhoG, muG)
_, fDL = Hydraulics.ff_via_churchill(ReL, epw, DL)
_, fDG = Hydraulics.ff_via_churchill(ReG, epw, DG)
tauL = Hydraulics.shear_stress(fDL, rhoL, vL)
tauG = Hydraulics.shear_stress(fDG, rhoG, vG)
tauI = Hydraulics.shear_stress(fDG, rhoG, vG - vL)
dPL = 0.0
dPG = 0.0
dPI = 0.0
return tauL * perL, tauG * perG, tauI * perI, dPL, dPG, dPI
def residue(self, t: float, y: np.ndarray, yp: np.ndarray, par=None):
#print(int(t*100)/100)
D = self.parameters['D']()
rhoL = self.parameters['rhoL']()
drhoLdP = self.parameters['drhoLdP']()
rhoG = self.parameters['rhoG']()
drhoGdP = self.parameters['drhoGdP']()
tetha = self.parameters['tetha']()
Pr = self.parameters['Pr']()
g = self.parameters['g']()
if y.ndim == 2:
tetha = np.repeat(np.array([tetha]), y.shape[1], axis=0).T
qL_lb = self.parameters['qL_lb'](t)
qG_lb = self.parameters['qG_lb'](t)
P_ub = self.parameters['P_ub'](t)
qL = self.variables["qL"].parse(y)
dqLdt = self.variables["qL"].parse(yp)
qG = self.variables["qG"].parse(y)
dqGdt = self.variables["qG"].parse(yp)
alphaL = self.variables["alphaL"].parse(y)
dalphaLdt = self.variables["alphaL"].parse(yp)
P = self.variables["P"].parse(y) * Pr
dPdt = self.variables["P"].parse(yp) * Pr
#alphaL = np.fmin(np.fmax(alphaL, 1e-6),1 -1e-6)
bc1 = BoundaryCondition(qL,
qL_lb,
kind=BoundaryConditionEnum.DIRICHLET,
regions_1=(RegionEnum.LOWER, ))
bc2 = BoundaryCondition(qG,
qG_lb,
kind=BoundaryConditionEnum.DIRICHLET,
regions_1=(RegionEnum.LOWER, ))
bc3 = BoundaryCondition(P / Pr,
P_ub / Pr,
kind=BoundaryConditionEnum.DIRICHLET,
regions_1=(RegionEnum.UPPER, ))
bc4 = BoundaryCondition(alphaL,
0.0,
kind=BoundaryConditionEnum.NEUMANN,
regions_1=(RegionEnum.LOWER, ),
regions_2=(RegionEnum.LOWER_PLUS_ONE, ))
alphaG = 1 - alphaL
dalphaGdt = -dalphaLdt
A = Geometry.area(D)
vL = Hydraulics.velocity(qL, rhoL, alphaL * A)
vG = Hydraulics.velocity(qG, rhoG, alphaG * A)
gammaL, gammaG, gammaI, dPL, dPG, dPI = self.model_closure(
self, t, qL, qG, alphaL, P)
dqLdx = self.grad_x(qL)
dqGdx = self.grad_x(qG)
cM = (alphaL / rhoL * drhoLdP + alphaG / rhoG * drhoGdP)
res_1 = dPdt + (dqLdx / rhoL + dqGdx / rhoG) / A / cM
res_2 = dalphaLdt + (
1 - 1 / cM * alphaL / rhoL * drhoLdP
) / A / rhoL * dqLdx - 1 / A / rhoG / cM * alphaL / rhoL * drhoLdP * dqGdx
res_3 = dqLdt + A * (dPL - rhoL * vL**2) * self.grad_x(
alphaL) + A * alphaL * (1 - drhoLdP * vL**2) * self.grad_x(
P) + A * alphaL * self.grad_x(dPL) + 2 * vL * self.grad_x_hrs(
qL, qL) + gammaL - gammaI + alphaL * rhoL * g * A * np.sin(
tetha)
res_4 = dqGdt + A * (dPG - rhoG * vG**2) * self.grad_x(
alphaG) + A * alphaG * (1 - drhoGdP * vG**2) * self.grad_x(
P) + A * alphaG * self.grad_x(dPG) + 2 * vG * self.grad_x_hrs(
qG, qG) + gammaG + gammaI + alphaG * rhoG * g * A * np.sin(
tetha)
#res_3 = dqLdt + A * alphaL*(1 - drhoLdP * vL**2) * self.grad_x(P + dPL) + 2*vL * self.grad_x_hrs(qL, qL) + gammaL - gammaI + alphaL * rhoL * g * A * np.sin(tetha)
#res_4 = dqGdt + A * alphaG*(1 - drhoGdP * vG**2) * self.grad_x(P + dPG) + 2*vG * self.grad_x_hrs(qG, qG) + gammaG + gammaI + alphaG * rhoG * g * A * np.sin(tetha)
eq1 = Equation(res_1, regions=(RegionEnum.CLOSED_OPEN, ))
eq2 = Equation(res_2, regions=(RegionEnum.OPEN_CLOSED, ))
eq3 = Equation(res_3, regions=(RegionEnum.OPEN_CLOSED, ))
eq4 = Equation(res_4, regions=(RegionEnum.OPEN_CLOSED, ))
eqs = Equations((
eq1,
eq2,
eq3,
eq4,
bc1,
bc2,
bc3,
bc4,
))
res = eqs()
ires = 0
return res, ires
def model_closure(obj, t, qL, qG, alphaL, P):
D = obj.parameters['D']()
g = obj.parameters['g']()
epw = obj.parameters['epw']()
rhoL = obj.parameters['rhoL']()
muL = obj.parameters['muL']()
rhoG = obj.parameters['rhoG']()
muG = obj.parameters['muG']()
tetha = obj.parameters['tetha']()
tension = obj.parameters['tension']()
alphaG = 1 - alphaL
A = Geometry.area(D)
vL = Hydraulics.velocity(qL, rhoL, alphaL * A)
vG = Hydraulics.velocity(qG, rhoG, alphaG * A)
vLS = Hydraulics.velocity(qL, rhoL, A)
vGS = Hydraulics.velocity(qG, rhoG, A)
vM = vGS + vLS
ReL = Dimensionless.reynolds(D, vL, rhoL, muL)
ReLS = Dimensionless.reynolds(D, vLS, rhoL, muL)
ReM = Dimensionless.reynolds(D, vM, rhoL, muL)
ffL, fDL = Hydraulics.ff_via_churchill(ReL, epw, D)
ffLS, fDLS = Hydraulics.ff_via_churchill(ReLS, epw, D)
ffM, fDM = Hydraulics.ff_via_churchill(ReM, epw, D)
# Gas Fraction in Slug
alphaS = 0.058 * (2 * (0.4 * tension / g / (rhoL - rhoG))**0.5 *
(2. * ffM / D * vM**3)**(2 / 5) *
(rhoL / tension)**(3 / 5) - 0.725)**2
alphaS = np.fmax(alphaS, np.zeros_like(alphaS))
alphaS = np.fmin(alphaS, np.ones_like(alphaS) - 0.48)
Rs = 1 - alphaS
# Slug length
if D > 0.038:
ls = np.exp(-3.287 + 4.589 * (np.log(D / 0.0254))**0.5)
else:
ls = 18.1 * D
# Slug frequency
Eo = np.sqrt(9.81 * D**2. * (rhoL - rhoG) / tension)
Nf = ((D**1.5) * (rhoL * (rhoL - rhoG) * g)**0.5) / muL
n = Nf / (260 + 0.85 * Nf)
wS = vGS / D * (0.0323 / 2. * vLS / vGS * ((rhoL /
(rhoL - rhoG))**0.5) *
(fDLS**-0.5) / (Eo**0.2))**n
# Slug Translational Velocity
C = 1.2
gD = (9.81 * D)**0.5
vD = 0.35 * gD * np.sin(tetha) + 0.54 * gD * np.cos(tetha)
vT = C * vM + vD
# Slug region lengths
lu = vT / wS
ls = np.fmin(ls, lu)
lf = lu - ls
lf = np.fmax(lf, ls * 1e-3)
lu = lf + ls
# Taylor Bubble holdup
alphaF = lu / lf * alphaG - ls / lf * alphaS
alphaF = np.fmax(1e-6, alphaF)
alphaF = min(1 - 1e-6, alphaF)
Rf = 1 - alphaF
# Slug Speeds
uL = (vLS + vT * (alphaG - alphaS)) / Rs
ub = (vGS - vT * (alphaG - alphaS)) / alphaS
# Taylor Bubble Speed
uf = vT - (vT - uL) * Rs / Rf
uG = vT - (vT - ub) * alphaS / alphaF
gammaL1, gammaG1, gammaI1, dPL1, dPG1, dPI1 = StratifiedClosure.model_closure(
obj, qL * uL / vL, qG * ub / vG, Rf, P)
gammaL2, gammaG2, gammaI2, dPL2, dPG2, dPI2 = BubbleClosure.model_closure(
obj, qL * uf / vL, qG * uG / vG, Rs, P)
gammaL = (gammaL1 * ls + gammaL2 * lf) / lu
gammaG = (gammaG1 * ls + gammaG2 * lf) / lu
gammaI = (gammaI1 * ls + gammaI2 * lf) / lu
dPL = (dPL1 * ls + dPL2 * lf) / lu
dPG = (dPG1 * ls + dPG2 * lf) / lu
dPI = (dPI1 * ls + dPI2 * lf) / lu
return gammaL, gammaG, gammaI, dPL, dPG, dPI