'''Chemical Engineering Design Library (ChEDL). Utilities for process modeling. Copyright (C) 2016, 2017 Caleb Bell Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ''' from math import log, pi import pytest from fluids.compressible import ( IGT, Fritzsche, Muller, Oliphant, P_critical_flow, P_isothermal_critical_flow, P_stagnation, Panhandle_A, Panhandle_B, Spitzglass_high, Spitzglass_low, T_critical_flow, T_stagnation, T_stagnation_ideal, Weymouth, is_critical_flow, isentropic_efficiency, isentropic_T_rise_compression, isentropic_work_compression, isothermal_gas, isothermal_work_compression, polytropic_exponent, stagnation_energy, ) from fluids.constants import day, foot, inch, psi from fluids.core import F2K from fluids.numerics import assert_close def test_isothermal_work_compression(): assert_close(isothermal_work_compression(1E5, 1E6, 300.0), 5743.425357533477, rtol=1e-05) def test_isentropic_work_compression(): dH = isentropic_work_compression(P1=1E5, P2=1E6, T1=300.0, k=1.4, eta=1) assert_close(dH, 8125.161295388634, rtol=1e-05) dH = isentropic_work_compression(P1=1E5, P2=1E6, T1=300, k=1.4, eta=0.78) assert_close(dH, 10416.873455626454, rtol=1e-05) dH = isentropic_work_compression(P1=1E5, P2=1E6, T1=300, k=1.4, eta=0.78, Z=0.9) assert_close(dH, 9375.186110063809, rtol=1e-05) # Other solutions - P1, P2, and eta P1 = isentropic_work_compression(W=9375.186110063809, P2=1E6, T1=300., k=1.4, eta=0.78, Z=0.9) assert_close(P1, 1E5, rtol=1E-5) P2 = isentropic_work_compression(W=9375.186110063809, P1=1E5, T1=300., k=1.4, eta=0.78, Z=0.9) assert_close(P2, 1E6, rtol=1E-5) eta = isentropic_work_compression(W=9375.186110063809, P1=1E5, P2=1E6, T1=300, k=1.4, Z=0.9, eta=None) assert_close(eta, 0.78, rtol=1E-5) with pytest.raises(Exception): isentropic_work_compression(P1=1E5, P2=1E6, k=1.4, T1=None) def test_isentropic_T_rise_compression(): T2 = isentropic_T_rise_compression(286.8, 54050.0, 432400., 1.4) assert_close(T2, 519.5230938217768, rtol=1e-05) T2 = isentropic_T_rise_compression(286.8, 54050, 432400, 1.4, eta=0.78) assert_close(T2, 585.1629407971498, rtol=1e-05) # Test against the simpler formula for eta=1: # T2 = T2*(P2/P1)^((k-1)/k) T2_ideal = 286.8*((432400/54050)**((1.4-1)/1.4)) assert_close(T2_ideal, 519.5230938217768, rtol=1e-05) def test_isentropic_efficiency(): eta_s = isentropic_efficiency(1E5, 1E6, 1.4, eta_p=0.78) assert_close(eta_s, 0.7027614191263858) eta_p = isentropic_efficiency(1E5, 1E6, 1.4, eta_s=0.7027614191263858) assert_close(eta_p, 0.78) with pytest.raises(Exception): isentropic_efficiency(1E5, 1E6, 1.4) # Example 7.6 of the reference: eta_s = isentropic_efficiency(1E5, 3E5, 1.4, eta_p=0.75) assert_close(eta_s, 0.7095085923615653) eta_p = isentropic_efficiency(1E5, 3E5, 1.4, eta_s=eta_s) assert_close(eta_p, 0.75) def test_polytropic_exponent(): assert_close(polytropic_exponent(1.4, eta_p=0.78), 1.5780346820809246) assert_close(polytropic_exponent(1.4, n=1.5780346820809246), 0.78) with pytest.raises(Exception): polytropic_exponent(1.4) def test_compressible(): T = T_critical_flow(473., 1.289) assert_close(T, 413.2809086937528) P = P_critical_flow(1400000., 1.289) assert_close(P, 766812.9022792266) assert not is_critical_flow(670E3, 532E3, 1.11) assert is_critical_flow(670E3, 101E3, 1.11) SE = stagnation_energy(125.) assert_close(SE, 7812.5) PST = P_stagnation(54050., 255.7, 286.8, 1.4) assert_close(PST, 80772.80495900588) Tst = T_stagnation(286.8, 54050., 54050*8., 1.4) assert_close(Tst, 519.5230938217768) Tstid = T_stagnation_ideal(255.7, 250., 1005.) assert_close(Tstid, 286.79452736318405) def test_Panhandle_A(): # Example 7-18 Gas of Crane TP 410M D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 42.56082051195928 # Test all combinations of relevant missing inputs assert_close(Panhandle_A(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Panhandle_A(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Panhandle_A(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Panhandle_A(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Panhandle_A(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Panhandle_A(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) # Sample problem from "Natural Gas Pipeline Flow Calculations" by "Harlan H. Bengtson" Q_panhandle = Panhandle_A(SG=0.65, Tavg=F2K(80), Ts=F2K(60), Ps=14.7*psi, L=500*foot, D=12*inch, P1=510*psi, P2=490*psi, Zavg=0.919, E=0.92) mmscfd = Q_panhandle*day/foot**3/1e6 assert_close(mmscfd, 401.3019451856126, rtol=1e-12) def test_Panhandle_B(): # Example 7-18 Gas of Crane TP 410M D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 42.35366178004172 # Test all combinations of relevant missing inputs assert_close(Panhandle_B(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Panhandle_B(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Panhandle_B(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Panhandle_B(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Panhandle_B(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Panhandle_B(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) def test_Weymouth(): D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 32.07729055913029 assert_close(Weymouth(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Weymouth(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Weymouth(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Weymouth(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Weymouth(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Weymouth(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) Q_Weymouth = Weymouth(SG=0.65, Tavg=F2K(80), Ts=F2K(60), Ps=14.7*psi, L=500*foot, D=12*inch, P1=510*psi, P2=490*psi, Zavg=0.919, E=0.92) mmscfd = Q_Weymouth*day/foot**3/1e6 assert_close(mmscfd, 272.5879686092862, rtol=1e-12) def test_Spitzglass_high(): D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 29.42670246281681 assert_close(Spitzglass_high(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Spitzglass_high(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Spitzglass_high(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Spitzglass_high(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Spitzglass_high(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Spitzglass_high(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) def test_Spitzglass_low(): D = 0.154051 P1 = 6720.3199 P2 = 0.0 L = 54.864 SG = 0.6 Tavg = 288.7 Q = 0.9488775242530617 assert_close(Spitzglass_low(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Spitzglass_low(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Spitzglass_low(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2, atol=1E-10) assert_close(Spitzglass_low(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Spitzglass_low(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Spitzglass_low(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) def test_Oliphant(): D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 28.851535408143057 assert_close(Oliphant(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Oliphant(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Oliphant(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Oliphant(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Oliphant(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Oliphant(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) def test_Fritzsche(): D = 0.340 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 39.421535157535565 assert_close(Fritzsche(D=D, P1=P1, P2=P2, L=L, SG=SG, Tavg=Tavg), Q) assert_close(Fritzsche(D=D, Q=Q, P2=P2, L=L, SG=SG, Tavg=Tavg), P1) assert_close(Fritzsche(D=D, Q=Q, P1=P1, L=L, SG=SG, Tavg=Tavg), P2) assert_close(Fritzsche(D=D, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), L) assert_close(Fritzsche(L=L, Q=Q, P1=P1, P2=P2, SG=SG, Tavg=Tavg), D) with pytest.raises(Exception): Fritzsche(D=0.340, P1=90E5, L=160E3, SG=0.693, Tavg=277.15) def test_Muller(): D = 0.340 mu = 1E-5 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 60.45796698148663 assert_close(Muller(D=D, P1=P1, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg), Q) assert_close(Muller(D=D, Q=Q, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg), P1) assert_close(Muller(D=D, Q=Q, P1=P1, L=L, SG=SG, mu=mu, Tavg=Tavg), P2) assert_close(Muller(D=D, Q=Q, P1=P1, P2=P2, SG=SG, mu=mu, Tavg=Tavg), L) assert_close(Muller(L=L, Q=Q, P1=P1, P2=P2, SG=SG, mu=mu, Tavg=Tavg), D) with pytest.raises(Exception): Muller(D=D, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg) def test_IGT(): D = 0.340 mu = 1E-5 P1 = 90E5 P2 = 20E5 L = 160E3 SG=0.693 Tavg = 277.15 Q = 48.92351786788815 assert_close(IGT(D=D, P1=P1, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg), Q) assert_close(IGT(D=D, Q=Q, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg), P1) assert_close(IGT(D=D, Q=Q, P1=P1, L=L, SG=SG, mu=mu, Tavg=Tavg), P2) assert_close(IGT(D=D, Q=Q, P1=P1, P2=P2, SG=SG, mu=mu, Tavg=Tavg), L) assert_close(IGT(L=L, Q=Q, P1=P1, P2=P2, SG=SG, mu=mu, Tavg=Tavg), D) with pytest.raises(Exception): IGT(D=D, P2=P2, L=L, SG=SG, mu=mu, Tavg=Tavg) def test_isothermal_gas(): mcalc = isothermal_gas(11.3, 0.00185, P1=1E6, P2=9E5, L=1000., D=0.5) assert_close(mcalc, 145.484757264) assert_close(isothermal_gas(11.3, 0.00185, P1=1E6, P2=9E5, m=145.484757264, D=0.5), 1000) assert_close(isothermal_gas(11.3, 0.00185, P2=9E5, m=145.484757264, L=1000., D=0.5), 1E6) assert_close(isothermal_gas(11.3, 0.00185, P1=1E6, m=145.484757264, L=1000., D=0.5), 9E5) assert_close(isothermal_gas(11.3, 0.00185, P1=1E6, P2=9E5, m=145.484757264, L=1000.), 0.5) with pytest.raises(Exception): isothermal_gas(11.3, 0.00185, P1=1E6, P2=9E5, L=1000.) with pytest.raises(Exception): isothermal_gas(rho=11.3, fd=0.00185, P1=1E6, P2=1E5, L=1000., D=0.5) with pytest.raises(Exception): isothermal_gas(rho=11.3, fd=0.00185, P2=1E6, P1=9E5, L=1000., D=0.5) # Newton can't converge, need a bounded solver P1 = isothermal_gas(rho=11.3, fd=0.00185, m=390., P2=9E5, L=1000., D=0.5) assert_close(P1, 2298973.786533209) # Case where the desired flow is greater than the choked flow's rate with pytest.raises(Exception): isothermal_gas(rho=11.3, fd=0.00185, m=400, P2=9E5, L=1000., D=0.5) # test the case where the ideal gas assumption is baked in: rho = 10.75342009105268 # Chemical('nitrogen', P=(1E6+9E5)/2).rho m1 = isothermal_gas(rho=rho, fd=0.00185, P1=1E6, P2=9E5, L=1000., D=0.5) assert_close(m1, 141.92260633059334) # They are fairly similar fd = 0.00185 P1 = 1E6 P2 = 9E5 L = 1000 D = 0.5 T = 298.15 # from scipy.constants import R # from thermo import property_molar_to_mass, Chemical, pi, log R = 296.8029514446658 # property_molar_to_mass(R, Chemical('nitrogen').MW) m2 = (pi**2/16*D**4/(R*T*(fd*L/D + 2*log(P1/P2)))*(P1**2-P2**2))**0.5 assert_close(m2, 145.48786057477403) def test_P_isothermal_critical_flow(): P2_max = P_isothermal_critical_flow(P=1E6, fd=0.00185, L=1000., D=0.5) assert_close(P2_max, 389699.7317645518)