def plot_condensation_curve(AR_min, AR_max, p_c, fp, T_ref):
gamma = fp.get_specific_heat_ratio(T=T_ref,
p=p_c) # [-] Specific heat ratio
# Determine maximum Mach number at exit
M_exit_max = IRT.Mach_from_area_ratio(
AR=AR_max, gamma=gamma) # [-] Max. Mach number at exit
M_exit_min = IRT.Mach_from_area_ratio(
AR=AR_min, gamma=gamma) # [-] Min. Mach number at exit
M_exit = np.linspace(start=M_exit_min, stop=M_exit_max,
num=50) # [-] Range of exit Mach numbers to evalulate
# Determine pressure at exit
PR_exit = IRT.pressure_ratio(M=M_exit,
gamma=gamma) # [-] Pressure ratio at exit
p_exit = p_c / PR_exit # [-] Exit pressure
# Determine saturation temperature at exit
T_sat_exit = fp.get_saturation_temperature(
p=p_exit) # [K] Saturation temperature at exit
# print(p_exit)
# print(T_sat_exit)
TR_exit = IRT.temperature_ratio(
M=M_exit, gamma=gamma) # [-] Temperature ratio at exit
T_chamber = T_sat_exit * TR_exit # [K] Chamber temperature that would result precisely in saturation temperature at nozzle exit
AR = IRT.area_ratio(
M=M_exit, gamma=gamma
) # [-] Area ratios corresponding to all specified mach numbers
plt.plot(
AR,
T_chamber,
label="$p_c ={:2.0f}$ bar , $T_c={:3.0f}$ K, $\\gamma={:1.3f}$".format(
p_c * 1e-5, T_ref, gamma))
def test_Anderson_table(self):
# Anderson2016 has a table in the back of his book for area ratio vs. Mach numbers
in_out = ((0.2e-1, 0.2894e2, 2), (0.1, 0.5822e1, 3), (0.5, 0.134e1, 3),
(0.78, 0.1047e1, 3), (1.22, 0.1037e1, 3), (2.45, 0.2517e1,
3),
(5.2, 0.2928e2, 2), (7.9, 0.1795e3, 1), (50, 0.1455e7, -3))
for input, output, places in in_out:
res = IRT.area_ratio(M=input, gamma=1.4)
self.assertAlmostEqual(res, output, places)
def plot_pressure_curve(AR_min, AR_max, p_c, fp, T_ref):
gamma = fp.get_specific_heat_ratio(T=T_ref,
p=p_c) # [-] Specific heat ratio
# Determine maximum Mach number at exit
M_exit_max = IRT.Mach_from_area_ratio(
AR=AR_max, gamma=gamma) # [-] Max. Mach number at exit
M_exit_min = IRT.Mach_from_area_ratio(
AR=AR_min, gamma=gamma) # [-] Min. Mach number at exit
M_exit = np.linspace(start=M_exit_min, stop=M_exit_max,
num=50) # [-] Range of exit Mach numbers to evalulate
# Determine pressure at exit
PR_exit = IRT.pressure_ratio(M=M_exit,
gamma=gamma) # [-] Pressure ratio at exit
p_exit = p_c / PR_exit # [-] Exit pressure
AR = IRT.area_ratio(
M=M_exit, gamma=gamma
) # [-] Area ratios corresponding to all specified mach numbers
plt.plot(AR,
p_exit * 1e-5,
label="{:2.0f} bar , $\\gamma={:1.2f}$".format(p_c * 1e-5, gamma))
def test_one(self):
# Mach number is 1 in the throat so area ratio must be 1.
expected_result = 1
res = IRT.area_ratio(M=1, gamma=1.4)
self.assertEqual(res, expected_result)
