def __init__(
self,
atmosphere: Atmosphere = Atmosphere(altitude=0),
velocity: float = 1.,
alpha: float = 0.,
beta: float = 0.,
p: float = 0.,
q: float = 0.,
r: float = 0.,
):
"""
An object that represents the instantaneous flight conditions of an aircraft.
Args:
atmosphere:
velocity: The flight velocity, expressed in true airspeed. [m/s]
alpha: The angle of attack. [degrees]
beta: The sideslip angle. (Reminder: convention that a positive beta implies that the oncoming air comes from the pilot's right-hand side.) [degrees]
p: The roll rate about the x_b axis. [rad/sec]
q: The pitch rate about the y_b axis. [rad/sec]
r: The yaw rate about the z_b axis. [rad/sec]
"""
self.atmosphere = atmosphere
self.velocity = velocity # TODO rename "airspeed"?
self.alpha = alpha
self.beta = beta
self.p = p
self.q = q
self.r = r
def op_point(self):
return OperatingPoint(
atmosphere=Atmosphere(altitude=self.altitude),
velocity=self.speed,
alpha=self.alpha,
beta=self.beta,
p=0,
q=0,
r=0,
)
def test_diff_atmosphere():
altitudes = np.linspace(-50e2, 150e3, 1000)
atmo_isa = Atmosphere(altitude=altitudes, method='isa')
atmo_diff = Atmosphere(altitude=altitudes)
temp_isa = atmo_isa.temperature()
pressure_isa = atmo_isa.pressure()
temp_diff = atmo_diff.temperature()
pressure_diff = atmo_diff.pressure()
assert max(abs(
(temp_isa - temp_diff) /
temp_isa)) < 0.025, "temperature failed for differentiable model"
assert max(abs(
(pressure_isa - pressure_diff) /
pressure_isa)) < 0.01, "pressure failed for differentiable model"
def plot_isa_residuals():
atmo = Atmosphere(altitude=altitudes, method='isa')
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(palette=sns.color_palette("husl"))
fig, ax = plt.subplots(1, 1, figsize=(6.4, 4.8), dpi=200)
plt.plot(altitudes, atmo.pressure() - pressures)
plt.xlabel(r"Altitude [m]")
plt.ylabel(r"Pressure Difference [Pa]")
plt.title(r"Pressure Difference between ASB ISA Model and ISA Table")
plt.tight_layout()
plt.legend()
plt.show()
fig, ax = plt.subplots(1, 1, figsize=(6.4, 4.8), dpi=200)
plt.plot(altitudes, atmo.temperature() - temperatures)
plt.xlabel(r"Altitude [m]")
plt.ylabel(r"Temperature Difference [K]")
plt.title(r"Temperature Difference between ASB ISA Model and ISA Table")
plt.tight_layout()
plt.legend()
plt.show()
def __init__(self,
atmosphere: Atmosphere = Atmosphere(altitude=0),
velocity: float = 10., # m/s
alpha: float = 5., # In degrees
beta: float = 0., # In degrees
p: float = 0., # About the body x-axis, in rad/sec
q: float = 0., # About the body y-axis, in rad/sec
r: float = 0., # About the body z-axis, in rad/sec
):
self.atmosphere = atmosphere
self.altitude = altitude
self.velocity = velocity
self.alpha = alpha
self.beta = beta
self.p = p
self.q = q
self.r = r
def test_isa_atmosphere():
for altitude, pressure, temperature, density, speed_of_sound in zip(
altitudes, pressures, temperatures, densities, speeds_of_sound):
atmo = Atmosphere(altitude=altitude, method='isa')
if altitude >= atmo._valid_altitude_range[
0] and altitude <= atmo._valid_altitude_range[1]:
fail_message = f"FAILED @ {altitude} m"
assert atmo.pressure() == pytest.approx(pressure,
abs=100), fail_message
assert atmo.temperature() == pytest.approx(temperature,
abs=1), fail_message
assert atmo.density() == pytest.approx(density,
abs=0.01), fail_message
assert atmo.speed_of_sound() == pytest.approx(speed_of_sound,
abs=1), fail_message
def equivalent_airspeed(self):
"""
Returns the equivalent airspeed associated with the current flight condition, in meters per second.
"""
return self.velocity * np.sqrt(self.atmosphere.density() / Atmosphere(
altitude=0, method="isa").density())