TST: add Defiance example flight acceptance test

tests/acceptance/test_defiance_rocket.py

@@ -0,0 +1,109 @@
+"""Acceptance test for the 2024 Defiance example flight."""
+
+from rocketpy import Environment, Flight, Rocket
+from rocketpy.motors import CylindricalTank, Fluid, HybridMotor
+from rocketpy.motors.tank import MassFlowRateBasedTank
+
+
+MEASURED_APOGEE_AGL = 9308.32
+MAX_RELATIVE_APOGEE_ERROR = 0.01
+
+
+def _build_defiance_flight():
+    """Build the deterministic Defiance example flight."""
+    environment = Environment(
+        latitude=47.966527,
+        longitude=-81.87413,
+        elevation=1383.4,
+        date=(2024, 8, 24, 0),
+    )
+    environment.set_atmospheric_model(type="custom_atmosphere", wind_v=1.0, wind_u=-2.9)
+
+    liquid_oxidizer = Fluid(name="N2O_l", density=960)
+    gaseous_oxidizer = Fluid(name="N2O_g", density=1.9277)
+    oxidizer_tank = MassFlowRateBasedTank(
+        name="oxidizer_tank",
+        geometry=CylindricalTank(radius_function=0.0665, height=1.79),
+        flux_time=6.5,
+        liquid=liquid_oxidizer,
+        gas=gaseous_oxidizer,
+        initial_liquid_mass=17,
+        initial_gas_mass=0,
+        liquid_mass_flow_rate_in=0,
+        liquid_mass_flow_rate_out=17 / 6.5,
+        gas_mass_flow_rate_in=0,
+        gas_mass_flow_rate_out=0,
+    )
+
+    motor = HybridMotor(
+        thrust_source="data/rockets/defiance/Thrust_curve.csv",
+        dry_mass=13.832,
+        dry_inertia=(1.801, 1.801, 0.0305),
+        center_of_dry_mass_position=0.780,
+        grain_number=1,
+        grain_separation=0,
+        grain_outer_radius=0.0665,
+        grain_initial_inner_radius=0.061,
+        grain_initial_height=1.25,
+        grain_density=920,
+        nozzle_radius=0.0447,
+        throat_radius=0.0234,
+        grains_center_of_mass_position=0.377,
+        coordinate_system_orientation="nozzle_to_combustion_chamber",
+    )
+    motor.add_tank(tank=oxidizer_tank, position=2.2)
+
+    rocket = Rocket(
+        radius=0.07,
+        mass=37.211,
+        inertia=(94.14, 94.14, 0.09),
+        center_of_mass_without_motor=3.29,
+        power_off_drag="data/rockets/defiance/DragCurve.csv",
+        power_on_drag="data/rockets/defiance/DragCurve.csv",
+        coordinate_system_orientation="tail_to_nose",
+    )
+    rocket.add_motor(motor, position=0.2)
+    rocket.add_nose(length=0.563, kind="vonKarman", position=4.947)
+    rocket.add_trapezoidal_fins(
+        n=3,
+        span=0.115,
+        root_chord=0.4,
+        tip_chord=0.2,
+        position=0.175,
+    )
+    rocket.add_tail(
+        top_radius=0.07,
+        bottom_radius=0.064,
+        length=0.0597,
+        position=0.1,
+    )
+    rocket.add_parachute(name="main", cd_s=2.2, trigger=305, sampling_rate=100, lag=0)
+    rocket.add_parachute(
+        name="drogue",
+        cd_s=1.55,
+        trigger="apogee",
+        sampling_rate=100,
+        lag=0,
+    )
+
+    return Flight(
+        rocket=rocket,
+        environment=environment,
+        inclination=85,
+        heading=90,
+        rail_length=10,
+    )
+
+
+def test_defiance_rocket_apogee_matches_measured_flight():
+    """Compare the Defiance example simulation with its measured apogee."""
+    flight = _build_defiance_flight()
+    simulated_apogee_agl = flight.apogee - flight.env.elevation
+    relative_error = (
+        abs(MEASURED_APOGEE_AGL - simulated_apogee_agl) / MEASURED_APOGEE_AGL
+    )
+
+    assert relative_error < MAX_RELATIVE_APOGEE_ERROR, (
+        f"Defiance apogee relative error is {relative_error:.2%}; "
+        f"expected less than {MAX_RELATIVE_APOGEE_ERROR:.2%}."
+    )