def _load(path, atmosphere=std_atm_earth()):
data = {}
with open(path) as f:
data = json.load(f)
engine = data.get('engine', {})
engine_name = engine.get('name', None)
# If name is specified, look for it in the engine database
# Then fall-back on database values if they're not given in the plane.json file
engine_in_db = engine_db.get(engine_name,
{}) if engine_name is not None else {}
T_a_sl = engine.get('thrust', engine_in_db.get('thrust', None))
cost_engines = engine.get('cost', engine_in_db.get('cost', None))
engine_count = data.get('engine_count', 1)
if T_a_sl is not None: T_a_sl *= engine_count
if cost_engines is not None: cost_engines *= engine_count
weight = data.get('weight', {'struct': 0, 'fuel': 0, 'payload': 0})
W_struct = weight.get('struct', 0)
W_fuel = weight.get('fuel', 0)
W_payload = weight.get('payload', 0)
W_engines = engine.get('weight', engine_in_db.get('weight',
0)) * engine_count
cost_struct = data.get('cost', None)
if (cost_struct is not None) and (cost_engines is not None):
cost_struct -= cost_engines
plane = Plane(
data.get('Cd_0', None),
data.get('e_w', None),
data.get('S', None),
data.get('b', None),
data.get('Cl_max', None),
data.get('Lam', None),
data.get('tc_max', None),
W_struct,
W_fuel,
W_engines,
W_payload,
engine.get('cj', engine_in_db.get('cj', None)),
T_a_sl,
data.get('n_struct', None),
atmosphere,
)
plane._description = data.get('description', None)
plane._cost_engines = cost_engines
plane._cost_struct = cost_struct
return plane
velocities)
plt.cla()
plt.clf()
plt.plot(velocities, P_a_0, '--b', label='P_a @ h = 0m')
plt.plot(velocities, P_r_0, '-b', label='P_r @ h = 0m')
plt.plot(velocities, P_a_45, '--r', label='P_a @ h = 4500m')
plt.plot(velocities, P_r_45, '-r', label='P_r @ h = 4500m')
plt.title('Power Available and Power Required for the F-117')
plt.xlabel('Velocity, V [m/s]')
plt.ylabel('Power [W]')
plt.legend(loc='upper right')
plt.show()
if __name__ == '__main__':
from haydens_code.atmosphere import std_atm_earth
from haydens_code.plane import Plane
# Initialize atmosphere object
atm = std_atm_earth()
# Initialize F-117 Warthog plane object
plane = Plane(0.042, None, 0.84, 84.8 / 13.2, 13.2, 1.2, None, None,
187000, 0.0, None, 96000, atm)
# plane = Plane(187000, 13.2, 84.8/13.2, 0.042, 0.84, 1.2, 96000)
QUESTION_2()
QUESTION_3()
# )
# Initialize MD-11 plane object
plane = Plane(Cd_0=0.018,
Em=None,
e=0.85,
chord=339 / 51.8,
span=51.8,
Cl_max=1.4,
Lam=35.0,
tc_max=0.12,
W_0=2710000,
W_fuel=None,
cj=None,
T_a_sl=800000,
atmosphere=std_atm_earth())
"""QUESTION 1 PLOT"""
plane.set_altitude(0) # meters
T_a = plane.jet_thrust_available() # N
V_limits = plane.speed_min_max(T_a) # m/s
V_range = np.arange(V_limits[0, 0], V_limits[1, 0] + 5, 5)
Cd_inc = plane.Cd(plane.Cd_i(plane.Cl(V_range)))
Cd_com = Cd_inc + plane.Cd_c(plane.Cl(V_range), V_range)
D_inc = plane.drag(Cd_inc, V_range) / 1000
D_com = plane.drag(Cd_com, V_range) / 1000
plt.plot(V_range, D_inc, '-r', label='Drag (incompressible)')
plt.plot(V_range, D_com, '--r', label='Drag (compressible)')
plt.plot(V_range, [T_a / 1000 for i in range(V_range.shape[0])],
'-b',
label='Thrust Available')