def test_one_phase_dP_dz_acceleration_example():
# This requires thermo!
from thermo import Stream, Vm_to_rho
from fluids import one_phase_dP, one_phase_dP_acceleration
import numpy as np
from scipy.integrate import odeint
from fluids.numerics import assert_close
P0 = 1E5
s = Stream(['nitrogen', 'methane'], T=300, P=P0, zs=[0.5, 0.5], m=1)
rho0 = s.rho
D = 0.1
def dP_dz(P, L, acc=False):
s.flash(P=float(P), Hm=s.Hm)
dPf = one_phase_dP(m=s.m,
rho=s.rhog,
mu=s.rhog,
D=D,
roughness=0,
L=1.0)
if acc:
G = 4.0 * s.m / (pi * D * D)
der = s.VolumeGasMixture.property_derivative_P(P=s.P,
T=s.T,
zs=s.zs,
ws=s.ws)
der = 1 / Vm_to_rho(der, s.MW)
factor = G * G * der
dP = dPf / (1.0 + factor)
return -dP
return -dPf
ls = linspace(0, .01)
dP_noacc = odeint(dP_dz, s.P, ls, args=(False, ))[-1]
s.flash(P=float(P0), Hm=s.Hm) # Reset the stream object
profile = odeint(dP_dz, s.P, ls, args=(True, ))
dP_acc = profile[-1]
s.flash(P=dP_acc, Hm=s.Hm)
rho1 = s.rho
dP_acc_numerical = dP_noacc - dP_acc
dP_acc_basic = one_phase_dP_acceleration(m=s.m,
D=D,
rho_o=rho1,
rho_i=rho0)
assert_close(dP_acc_basic, dP_acc_numerical, rtol=1E-4)
def test_one_phase_dP_dz_acceleration_example():
# This requires thermo!
from thermo import Stream, Vm_to_rho
from fluids import one_phase_dP, one_phase_dP_acceleration
import numpy as np
from scipy.integrate import odeint
from numpy.testing import assert_allclose
P0 = 1E5
s = Stream(['nitrogen', 'methane'], T=300, P=P0, zs=[0.5, 0.5], m=1)
rho0 = s.rho
D = 0.1
def dP_dz(P, L, acc=False):
s.flash(P=float(P), Hm=s.Hm)
dPf = one_phase_dP(m=s.m, rho=s.rhog, mu=s.rhog, D=D, roughness=0, L=1)
if acc:
G = 4.0*s.m/(np.pi*D*D)
der = s.VolumeGasMixture.property_derivative_P(P=s.P, T=s.T, zs=s.zs, ws=s.ws)
der = 1/Vm_to_rho(der, s.MW)
factor = G*G*der
dP = dPf/(1.0 + factor)
return -dP
return -dPf
ls = np.linspace(0, .01)
dP_noacc = odeint(dP_dz, s.P, ls, args=(False,))[-1]
s.flash(P=float(P0), Hm=s.Hm) # Reset the stream object
profile = odeint(dP_dz, s.P, ls, args=(True,))
dP_acc = profile[-1]
s.flash(P=dP_acc, Hm=s.Hm)
rho1 = s.rho
dP_acc_numerical = dP_noacc - dP_acc
dP_acc_basic = one_phase_dP_acceleration(m=s.m, D=D, rho_o=rho1, rho_i=rho0)
assert_allclose(dP_acc_basic, dP_acc_numerical, rtol=1E-4)