def __init__(self, initial_pos, initial_vel, atmosphere):
# setup physical properties
radius = 3.66 / 2 # meters
# ignore the side boosters for now - and use fins with a drag and lift
# curve
area = math.pi * radius**2
# I'm not sure about these numbers. Not sure why thrust is ~20x weight
# fully loaded. For now set throttle to 5 or 6% to get realistic
# acceleration
mass = 1420000 / 9.8 # kg
thrust = 22241102 # N
length = 70 # m
# cylinder
# 1/12 * mass * length^2 + 1/4 * mass * radius^2
moment = 1 / 12 * mass * length**2 + 1 / 4 * mass * radius**2
state = physics.State(position=initial_pos,
velocity=initial_vel,
orientation=Angle(90))
Airplane.__init__(self, state, mass, moment, atmosphere)
# setup aerodynamic properties
drag_curve = drag.Parasitic(.35)
surface = flight.Surface("rocket",
atmosphere=atmosphere,
drag_curve=drag_curve,
area=area)
stab_lift_curve = lift.LiftingLine(3.62)
stab_drag_curve = drag.LiftingLine(3.62, efficiency_factor=0.6)
stab = Surface("stabilizer", Vector2D(-33, 0), 0, Angle(0), 136,
stab_lift_curve, stab_drag_curve, atmosphere)
self._surfaces = [surface, stab]
engine = Engine("1d merlin", Vector2D(-21, 0), Angle(0), 0, thrust)
engine.set_throttle(100)
self._engines = [engine]
def __init__(self, position, velocity):
atmosphere = Atmosphere()
state = State(position, velocity, Angle(0), 0)
Airplane.__init__(self, state, self._mass(),
self._mass_moment_of_inertia(), atmosphere)
wing_lift_curve = lift.Linear(6.98, 0.29, 5.5)
wing_drag_curve = drag.LiftingLine(6.98, 0.0305, 0.75)
self._wing = Surface("wing", Vector2D(0, 0), 0, Angle(2.4), 510.97,
wing_lift_curve, wing_drag_curve, atmosphere)
stab_lift_curve = lift.LiftingLine(3.62)
stab_drag_curve = drag.LiftingLine(3.62, efficiency_factor=0.6)
self._horizontal_stabilizer = Surface("stabilizer", Vector2D(-33,
0), 0,
Angle(0), 136, stab_lift_curve,
stab_drag_curve, atmosphere)
fusilage_drag_curve = drag.Parasitic(0.27)
# 747 cabin = ~19x6 meters
self._fusilage = Surface("fusilage", self.cg(), 0, Angle(0), 118, None,
fusilage_drag_curve, atmosphere)
self._surfaces = []
self._surfaces.append(self._wing)
self._surfaces.append(self._horizontal_stabilizer)
self._surfaces.append(self._fusilage)
# don't have yaw forces (or a 3rd axis) to put engines out on wings
# so they all go at cg
self._engines = []
self._engines.append(Engine("engine 1", self.cg(), Angle(0), 0,
275000))
self._engines.append(Engine("engine 2", self.cg(), Angle(0), 0,
275000))
self._engines.append(Engine("engine 3", self.cg(), Angle(0), 0,
275000))
self._engines.append(Engine("engine 4", self.cg(), Angle(0), 0,
275000))
def test_cla_lifting_line(self):
lift_curve = lift.LiftingLine(7.37)
self.assertAlmostEqual(4.942, lift_curve.lift_slope_3d, 3)
def get_cessna_wing(self):
wing_lift_curve = lift.LiftingLine(7.37)
wing_drag_curve = drag.LiftingLine(7.37, 0.027, 0.75)
return Surface("cessna 172 wing", Vector2D(0, 0), 0, Angle(0), 16.2,
wing_lift_curve, wing_drag_curve, Atmosphere())
def get_cessna_lift_curve(self):
return lift.LiftingLine(7.37)