def test_01(self):
# Truth values from NASA RP 1046
Value = SA.alt2press(5000)
Truth = 24.8959
self.assertLessEqual(RE(Value, Truth), 1e-5)
def __init__(self, h):
# Cantera Solution object
self.gas = ct.Solution('air.xml')
# Discretised altitude steps
self.h = h
# Average molecular diameter of gas
self.d = 4E-10
self.steps = len(h)
self.rho = np.zeros(self.steps)
self.p = np.zeros(self.steps)
self.T = np.zeros(self.steps)
self.a = np.zeros(self.steps)
self.k = np.zeros(self.steps)
self.mu = np.zeros(self.steps)
for index, alt in enumerate(self.h):
self.rho[index] = atm.alt2density(alt, alt_units='m', density_units='kg/m**3')
self.p[index] = atm.alt2press(alt, press_units='pa', alt_units='m')
self.T[index] = atm.alt2temp(alt, alt_units='m', temp_units='K')
self.a[index] = atm.temp2speed_of_sound(self.T[index], temp_units='K', speed_units='m/s')
for index, alt in enumerate(self.h):
self.gas.TP = self.T[index], self.p[index]
self.k[index] = self.gas.cp / self.gas.cv
self.mu[index] = self.gas.viscosity
print 'ATMOSPHERIC MODEL COMPUTED (US76)'
return None
def test_06(self):
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2press(65322, press_units='pa', alt_units='m')
Truth = 9.4609
self.assertLessEqual(RE(Value, Truth), 5e-5)
def test_03(self):
# test pa and m
# Truth values from NASA RP 1046
Value = SA.alt2press(25000, alt_units='m', press_units='pa')
Truth = 2511.01
self.assertLessEqual(RE(Value, Truth), 1e-5)
def test_02(self):
# test psf
# Truth values from NASA RP 1046
Value = SA.alt2press(49000, press_units='psf')
Truth = 254.139
self.assertLessEqual(RE(Value, Truth), 1e-5)
def test_07(self):
# test units in other order
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2press(80956, press_units='pa', alt_units='m')
Truth = 0.75009
self.assertLessEqual(RE(Value, Truth), 1e-4)
def __init__(self, h, T_thermosphere):
# Cantera Solution object
self.gas = ct.Solution('air.xml')
# Discretised altitude steps
self.h = h
# Average molecular diameter of gas
self.d = 4E-10
# Ratio of specific heats
self.steps = len(h)
self.rho = np.zeros(self.steps)
self.p = np.zeros(self.steps)
self.T = np.zeros(self.steps)
self.a = np.zeros(self.steps)
self.k = np.zeros(self.steps)
self.mu = np.zeros(self.steps)
# Call Jacchia77 model
data = j77.j77sri(np.max(h), T_thermosphere)
data_np = np.array(data)
h_int = spint.griddata
T_int = spint.griddata
mw_int = spint.griddata
n = spint.griddata
for index, alt in enumerate(self.h):
self.rho[index] = atm.alt2density(alt, alt_units='m', density_units='kg/m**3')
self.p[index] = atm.alt2press(alt, press_units='pa', alt_units='m')
self.T[index] = atm.alt2temp(alt, alt_units='m', temp_units='K')
self.a[index] = atm.temp2speed_of_sound(self.T[index], temp_units='K', speed_units='m/s')
for index, alt in enumerate(self.h):
self.gas.TP = self.T[index], self.p[index]
self.k[index] = self.gas.cp / self.gas.cv
self.mu[index] = self.gas.viscosity
return None
piece.append('2400'.center(cols))
piece.append('2200'.center(cols))
piece.append('2300'.center(cols))
piece.append('2400'.center(cols))
piece.append('2500'.center(cols))
full_line = '|'.join(piece)
print('|' + full_line + '|')
for alt in range(0, 16000, 1000):
piece = []
piece.append(str(alt).rjust(col1))
temp = SA.alt2temp(alt, temp_units='F')
temp = int(temp)
piece.append(str(temp).rjust(col2))
press = SA.alt2press(alt)
pwr = .55 * max_pwr
for rpm in range(2100, 2500, 100):
mp = float(io360a.pwr2mp(pwr, rpm, alt))
if press - mp < diff:
piece.append('FT'.center(col2))
else:
piece.append(str(round(mp, 1)).center(col2))
pwr = .65 * max_pwr
for rpm in range(2100, 2500, 100):
mp = float(io360a.pwr2mp(pwr, rpm, alt))
if press - mp < diff:
piece.append('FT'.center(col2))
else:
