Hacker A40-12 S V2 / Jeti SPIN Pro 66 / Aeronaut CAM 14x8 tailless UAV · baseline-to-optimized evidence with an embedded model of the actual exported mesh.
Headline values come from the optimized aircraft’s own artifacts. Every gate below carries one-line evidence and a source path; the green state is not inferred from a stage’s top-level flag alone.
NTNU May-2023 Skywalker X8 reproduction translated from the source-cited design-time input pack without validation maneuvers or published aerodynamic coefficients. The equivalent trapezoid, NACA 0012 section, washout, molded body, fin attachment, packaging, structure, and drag are declared conceptual abstractions. The motor/controller package is modeled inside the aft body; the external pusher disk is represented by the published thrust deck. The measured 3.364 kg flight mass includes propulsion and battery. Liquid fuel, battery energy, range, and endurance are not claimed. Fuselage fineness, bay dimensions, component packaging, fin attachment, structural properties, mission screens, and solver settings are engineering assumptions checked by the canonical internal gates, not source or validation claims.
| Requirement | Target | Predicted | Verdict |
|---|---|---|---|
| Engine | Hacker A40-12 S V2 / Jeti SPIN Pro 66 / Aeronaut CAM 14x8 | Hacker A40-12 S V2 / Jeti SPIN Pro 66 / Aeronaut CAM 14x8 | MET |
| Payload | 0.0 kg | 0.0 kg | MET |
| Endurance | not claimed | n/a | N/A |
| Dash | maximize; M ≤ 0.11 | 134 km/h · M 0.11 | MET |
| Configuration | sketch envelope | 2.10 m span · 25.0° sweep | MET |
Source and delivered specifications deserialize; every source-locked field is unchanged except declared trim and same-run component-stability constants.
source=yes; optimized=yes; engine requirement=yes; payload requirement=yes; reproduction frozen=yes
design.yaml · Upstream response: Correct design.yaml values or schema violations; never patch generated JSON.The exported mesh—not only the intended parameters—matches the requested aircraft.
read-back=yes; bbox=yes; mesh checks=18
optimized/geometry.json · Upstream response: Fix OpenVSP construction, section placement, or source geometry, then rerun geometry.Engine, payload, and fuel occupy non-overlapping usable volume.
fuel-volume margin 0.010 m³; engine/payload clear
optimized/geometry.json · Upstream response: Move/resize bays, increase body or tank volume, or reduce required fuel.Measured static margin is inside the mission band at full and reserve fuel.
independently measured SM full 0.080; reserve 0.080 MAC
optimized/aero.json · Upstream response: Adjust wing, payload, fuel, or engine longitudinal stations; recalibrate NP only with OAS evidence.The aircraft closes lift and pitching moment at its selected wing twist or tail incidence.
washout 4.000° vs spec 4.000°; CM residual -0.0010
optimized/aero.json · Upstream response: Adjust twist/tail incidence, airfoil moment, CG/wing station, or OAS-backed calibration.Wing loading remains compatible with the documented CLmax assumption.
Vstall 8.474 m/s ≤ 12.0 m/s at CLmax 1.00
optimized/aero.json · Upstream response: Increase wing area, reduce MTOW, or change CLmax only with aerodynamic evidence.Source-locked geometry clears either the minimum conceptual fin-volume screen or same-run restoring/damping derivative checks; no upper-band sizing claim or fin-sizing optimum is made.
source Vv 0.0148; same-run Cnβ 0.0159, Cnr -0.0095 (source-locked reproduction)
optimized/validation.json · Upstream response: Correct the source geometry or remove the reproduction claim; do not resize a source-locked fin to make the screen pass.The OAS wingbox survives the positive limit load with the encoded safety factor.
+4g failure index -0.958; CL 0.792/0.792; lift closed=yes; mass closed=yes; tip deflection 0.001 m
optimized/structures.json · Upstream response: Increase skin/spar gauge, section depth, or material capability; reduce load only by changing requirements.The closed fuel budget meets endurance and installed thrust covers modeled drag.
endurance not claimed for electric reproduction; cruise/dash thrust ≥ buildup drag
optimized/aero.json + baseline/mdo.json · Upstream response: Trade fuel, mass, drag, cruise condition, wing geometry, or propulsion assumptions upstream.Source coordinates remain frozen while a separate OAS solve checks trim and structures; stability retains its declared independent-derivative or component-model evidence label.
feasible=yes; driver=yes; post-delivery verify=yes; calibration=yes; frozen=yes; 1 starts
baseline/mdo.json · Upstream response: Fix source serialization, trim/structures verification, or stability provenance; do not optimize frozen reproduction coordinates.Delivered proportions stay inside the hard identity bound and every soft-prior departure is explained.
span/L 2.66; root/L 0.52; sweep 25.0°; 0 scored shape departures; 0 total audit records
optimized/design.yaml + baseline/mdo.json · Upstream response: Fix unjustified departures or the upstream physics; never widen the hard identity bound silently.Required analytical identities and declared-scope solver checks pass, method spread is disclosed, and headline values reproduce from same-phase artifacts.
core 13/13; VSPAERO/OAS CLα ratio 0.958; NP method spread 0.039 MAC (diagnostic); report Mach 0.110 vs recomputed 0.110; MTOW report/aero/MDO 3.364/3.364/3.364 kg; L/D report/aero/MDO 7.504/7.504/7.504
optimized/validation.json + optimized/report.json · Upstream response: Use the failed validation check name to fix its upstream model or calibration.The first figure and interactive hero are rendered from the exported STL itself. The remaining figures expose the numerical story: what changed, where drag and mass live, and how close the design sits to its constraints.
The baseline is the aircraft as drawn; the optimizer answers what it presented. Both columns below are read from their own phase artifacts — the two phases are different aircraft and are never mixed inside one number. The delivered configuration is checked by a separate OAS solve; stability evidence is labeled by method.
| Quantity | Baseline | Optimized | Change |
|---|---|---|---|
| Wing span | 2.100 m | 2.100 m | unchanged |
| Wing area | 0.750 m² | 0.750 m² | unchanged |
| Aspect ratio | 5.88 | 5.88 | unchanged |
| Taper | 0.732 | 0.732 | unchanged |
| LE sweep | 25.0 deg | 25.0 deg | unchanged |
| Airfoil | NACA 0012 | NACA 0012 | unchanged |
| Thickness t/c | 0.120 | 0.120 | unchanged |
| Tip twist | -2.00 deg | -2.00 deg | unchanged |
| MTOW | 3.36 kg | 3.36 kg | unchanged |
| Fuel | 0.00 kg | 0.00 kg | unchanged |
| Dash speed | 134 km/h | 134 km/h | unchanged |
| Cruise L/D | 7.50 | 7.50 | unchanged |
| Stall speed | 8.5 m/s | 8.5 m/s | unchanged |
| Static margin (full) | 0.080 MAC | 0.080 MAC | unchanged |
| Trim wing twist | -2.00 deg | -2.00 deg | unchanged |
Mission, topology, and proportions become a validated, version-controlled concept specification.
Fuel and MTOW close without an endurance claim; artifact geometry and OAS models establish the reference.
Source coordinates remain frozen while same-run OAS closes model calibration and verifies trim, stability, and structures.
Separate OAS and mesh-truth checks produce the 134 km/h delivered configuration.
| Start | Dash | Endurance | MTOW | Feasible |
|---|---|---|---|---|
| deterministic_reference_closure | 134 km/h | n/a | 3.4 kg | yes |
| Attempt | Internal band | Evaluated full / reserve | Verdict |
|---|---|---|---|
| same-run OAS NP | model error ≤ 0.05 MAC | 0.059 / 0.000 MAC | PASS |
Analytical identities, OAS comparisons, VSPAERO, artifact-level geometry checks, and stretch solvers test different failure modes. TACS and SU2 are shown as calibration data—not promoted into certification evidence.
| Check | Class | Observed | Reference | Verdict |
|---|---|---|---|---|
| k450 tsfc kg per kgf hr | core gate | 1.467 | 1.467 | PASS |
| breguet round trip | core gate | 7,200.0 | 7,200.0 | PASS |
| isa T sl | core gate | 288.1 | 288.1 | PASS |
| isa rho sl | core gate | 1.225 | 1.225 | PASS |
| oas induced drag vs elliptic | core gate | 0.003 | 0.003 | PASS |
| cantilever deflection identity | core gate | 0.014 | 0.014 | PASS |
| thin airfoil cm ac | core gate | {"0012":0.0,"2412":-0.05311944998613994} | {"0012":0.0,"2412":-0.047} | PASS |
| fin volume coefficient | core gate | 0.015 | >= 0.02 or passing same-run directional derivatives (source-locked reproduction) | PASS |
| fin te within body | core gate | -0.017 | <= 0.0158 m | PASS |
| neutral point model vs oas | core gate | 0.464 | 0.464 | PASS |
| wing mass buildup vs oas | core gate | 1.587 | 0 < wing structural mass < 3.364 kg reference OE mass | PASS |
| vspaero vs oas CL | core gate | 0.958 | n/a | PASS |
| elevon cm delta vspaero vs oas | core gate | n/a | pitch trim control is not elevon | PASS |
| tacs artifact schema | stretch calibration | tacs | stretch; schema presence only | PASS |
| su2 convergence reported separately | stretch calibration | [false,false] | stretch; 'ok' means ran+parsed, 'converged' is the residual verdict | PASS |
Component extents, fin verticality, whole-model envelope, and root attachment are measured on exported STL files.
VSPAERO versus OAS lift-curve slope across α=[3.0, 7.0]° on the same lifting surfaces. Absolute CL has different camber fidelity; CD is intentionally not compared.
Shell mass 0.782 kg; SU2 cruise converged=no, rmsρ=-2.294.
This section preserves the details needed to challenge or reproduce the design. Values are generated from the delivered optimized YAML and same-directory stage outputs.
| Parameter | Value |
|---|---|
| Fuselage | 0.79 × 0.18 × 0.17 m |
| Wing | 2.10 m span · 0.75 m² · AR 5.88 |
| Planform | root 0.41 m · taper 0.732 · LE sweep 25.0° |
| Airfoil / thickness | NACA 0012 · t/c 0.120 |
| Twist | root +2.00° · tip -2.00° |
| Twin fins | 0.22 m span each · 12.0° cant |
| Propulsion | Hacker A40-12 S V2 / Jeti SPIN Pro 66 / Aeronaut CAM 14x8 · 60.4 N SL |
| Fuel | 0.00 kg delivered spec |
| Structure | wingbox · skin 1.00 mm · spar 1.50 mm |
| Material | Assumed quasi-isotropic CFRP equivalent · yield 250 MPa |
| Item | Mass | x station |
|---|---|---|
| operating_empty | 3.36 kg | 0.435 m |
| Python | 3.12.3 |
| OpenVSP | OpenVSP 3.51.3 |
| OpenMDAO | 3.45.0 |
| OpenAeroStruct | 2.12.0 |
| Pydantic | 2.13.4 |
| NumPy | 2.5.2 |
| Matplotlib | 3.11.1 |
name: ntnu-x8
notes: NTNU May-2023 Skywalker X8 reproduction translated from the source-cited design-time
input pack without validation maneuvers or published aerodynamic coefficients. The
equivalent trapezoid, NACA 0012 section, washout, molded body, fin attachment, packaging,
structure, and drag are declared conceptual abstractions. The motor/controller package
is modeled inside the aft body; the external pusher disk is represented by the published
thrust deck. The measured 3.364 kg flight mass includes propulsion and battery.
Liquid fuel, battery energy, range, and endurance are not claimed. Fuselage fineness,
bay dimensions, component packaging, fin attachment, structural properties, mission
screens, and solver settings are engineering assumptions checked by the canonical
internal gates, not source or validation claims.
sketch:
treatment: reproduction
hard_scale: 1.0
fidelity_weight: 1.0
span_over_length: 2.6582278481012658
span_over_length_tol: 0.03
root_over_length: 0.5221154312153242
root_over_length_tol: 0.03
le_sweep_deg: 25.0
le_sweep_tol_deg: 5.0
taper: 0.7317226765403747
taper_tol: 0.05
x_le_root_over_length: 0.1864556962025316
x_le_root_over_length_tol: 0.04430379746835443
payload_bay_x_lo_m: null
payload_bay_x_hi_m: null
fuel_tank_x_lo_m: null
fuel_tank_x_hi_m: null
twist_tip_lo_deg: -3.0
twist_tip_hi_deg: -1.0
fin_span_m: 0.22
fin_span_tol_m: 0.03
fin_root_chord_m: 0.3
fin_root_chord_tol_m: 0.04
fin_le_sweep_deg: 35.0
fin_le_sweep_tol_deg: 5.0
fin_cant_deg: 12.0
fin_cant_tol_deg: 5.0
fin_x_le_m: 0.56
fin_x_le_tol_m: 0.08
engine:
name: Hacker A40-12 S V2 / Jeti SPIN Pro 66 / Aeronaut CAM 14x8
energy_source: electric
diameter_m: 0.06
length_m: 0.12
dry_mass_kg: 0.5
installation: internal
installation_count: 1
x_m: 0.72
lateral_offset_m: 0.0
z_m: 0.02
max_thrust_sl_n: 60.3845350822
fuel_flow_max_kg_s: 0.0
thrust_lapse_k_mach: 0.0
thrust_lapse_floor: 1.0
tsfc_part_a: 1.0
tsfc_part_b: 0.0
tsfc_mach_k: 0.0
min_throttle: 0.3
fuel_density_kg_m3: 800.0
nacelle_frontal_cd: 0.08
deck:
name: Published X8 electric thrust deck at rho=1.225 kg/m^3
points:
- altitude_m: 0.0
mach: 0.0
throttle: 0.3
thrust_n: 6.1245397711
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.0
throttle: 0.6
thrust_n: 23.215699427
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.0
throttle: 1.0
thrust_n: 60.3845350822
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.05289543933588392
throttle: 0.6
thrust_n: 10.979210524
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.05289543933588392
throttle: 1.0
thrust_n: 44.0867415841
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.07346588796650545
throttle: 0.6
thrust_n: 3.5675422739
fuel_flow_kg_s: 0.0
- altitude_m: 0.0
mach: 0.07346588796650545
throttle: 1.0
thrust_n: 34.6208306371
fuel_flow_kg_s: 0.0
interpolation: condition-idw
extrapolation: clamp
altitude_scale_m: 10000.0
mach_scale: 1.0
wing:
span_m: 2.1
root_chord_m: 0.4124711906601062
taper: 0.7317226765403747
le_sweep_deg: 25.0
dihedral_deg: 0.0
twist_root_deg: 2.0
twist_tip_deg: -2.0
t_over_c: 0.12
airfoil: '0012'
x_le_root_m: 0.1473
z_root_m: 0.0
sections: null
tip_chord_m: 0.3018145236256081
area_m2: 0.75
aspect_ratio: 5.88
mac_m: 0.36
y_mac_m: 0.49788911657654805
x_le_mac_m: 0.3794695079716712
x_ac_m: 0.4694695079716712
fuselage:
length_m: 0.79
max_width_m: 0.18
max_height_m: 0.17
nose_fine_ratio: 0.22
tail_fine_ratio: 0.28
payload_bay_length_m: 0.2
payload_bay_width_m: 0.12
payload_bay_height_m: 0.1
payload_bay_x_m: 0.18
fuel_tank_x_m: 0.435
stations: null
fairings: null
vtail:
count: 2
root_attachment: derived
span_m: 0.22
root_chord_m: 0.3
taper: 0.45
le_sweep_deg: 35.0
cant_deg: 12.0
t_over_c: 0.1
x_le_m: 0.56
y_root_m: 0.88
z_root_m: 0.02
area_m2: 0.04785
htail:
span_m: 0.0
root_chord_m: 0.1
taper: 0.5
le_sweep_deg: 0.0
t_over_c: 0.1
x_le_m: 0.49
z_m: 0.02
incidence_deg: 0.0
area_m2: 0.0
mission:
endurance_s: 1.0
endurance_required: false
payload_kg: 0.0
cruise_altitude_m: 175.0
dash_altitude_m: 175.0
cruise_mach: 0.053000154399591666
cruise_cl: 0.2254109964699504
dash_mach_cap: 0.11
limit_positive_g: 4.0
limit_negative_g: -2.0
safety_factor: 1.5
static_margin_min: 0.03
static_margin_max: 0.1
reserve_fuel_fraction: 0.0
cl_max: 1.0
cl_max_basis: aircraft
stall_speed_max_mps: 12.0
pitch_trim_control: auto
structures:
fem_model_type: wingbox
spar_thickness_m: 0.0015
skin_thickness_m: 0.001
tube_radius_m: 0.012
tube_thickness_m: 0.001
wing_weight_ratio: 1.2
n_spanwise: 9
n_chordwise: 3
material:
name: Assumed quasi-isotropic CFRP equivalent
E_pa: 35000000000.0
nu: 0.3
yield_pa: 250000000.0
density_kg_m3: 1600.0
G_pa: 13461538461.538462
spanwise: null
modal_calibration: []
sensor_stations: []
drag:
interference_fraction: 0.08
protuberance_cd0: 0.004
mass:
fuel_mass_kg: 0.0
fuel_mass_mode: fixed
fuel_capacity_kg: null
listed_mass_min_kg: null
listed_mass_max_kg: null
listed_mass_state: null
operating_empty_mass_kg: 3.364
operating_empty_cg_x_m: 0.435
systems_kg: 0.0
landing_gear_fraction: 0.0
avionics_kg: 0.0
contingency_fraction: 0.0
flight_dynamics:
enabled: true
reference_airspeed_mps: 18.0
reference_altitude_m: 175.0
inertia:
ixx_kg_m2: 0.325
iyy_kg_m2: 0.14
izz_kg_m2: 0.4
ixy_kg_m2: 0.0
ixz_kg_m2: 0.029
iyz_kg_m2: 0.0
source: "L\xF8w-Hansen et al. May-2023 configuration; bifilar provenance in Reinhardt\
\ et al."
control_surfaces:
- id: elevon
host: wing
span_start_fraction: 0.48
span_end_fraction: 0.94
chord_fraction: 0.2
max_up_deg: 20.0
max_down_deg: 20.0
neutral_deg: null
trim_deflection_deg: 0.0
source: Visible X8 elevons and Gryte et al. +/-20 degree control sweeps
mixing:
- id: collective_elevon
mode: collective
axis: pitch
gain: 1.0
- id: differential_elevon
mode: differential
axis: roll
gain: 1.0
aeroelastic:
enabled: false
strip_count: 48
modes_per_family: 1
frequency_min_hz: 0.5
frequency_max_hz: 30.0
frequency_points: 160
maximum_reduced_frequency: 0.3
elastic_axis_fraction_chord: 0.4
lift_curve_slope_per_rad: null
calibration_id: none
allow_diagonal_inertia_approximation: true
calibration_id: ntnu-x8-low-re-elevon-v1
solver:
oas_with_viscous: true
oas_with_wave: false
optimize_maxiter: 35
optimize_tol: 1.0e-05
fd_step: 0.001
vspaero_wake_iters: 20
vspaero_convergence_factor: 0.01
su2_maxiter: 200
gmsh_lc_m: 0.08
stability_method: lifting_surface
np_shift_mac: -0.015612415298241498
wing_body_np_mac: null
wing_body_cl_alpha_per_deg: null
cm_washout_per_deg: 0.00362
tail_incidence_offset_deg: 0.0
tail_lift_effectiveness_factor: 1.0
tail_lift_effectiveness_source: null
elevon_effectiveness_factor: 1.0
elevon_effectiveness_source: null
n_ult: 6.0