CRYOPULSE P3.9 / CHASSIS AND AIRFLOW DEVELOPMENT

This is a reproducible design study. Physical measurements: 0.

The P3.7 vehicle result remains frozen. P3.9 adds a finite-rate mean upper-vent
angle extension, a front-projection active-camber linkage and a new rigid body
packaging candidate. The active-camber mechanism is not integrated into the
published vehicle mass, tyre law or electrical loads. No new tyre grip, cold
propulsion or full-speed drag gain is assigned.

The package includes the required local vehicle-model source and runtime input
files, new CAD, exact topology mesh and recorded results. Python requirements:
numpy, scipy, matplotlib, gmsh. A C++ compiler is required for the existing wheel
kernel. Geometry regeneration uses OpenCASCADE through Gmsh 4.15.2. The full CFD
mesh gate uses OpenFOAM v2412, separately installed; no flow result is claimed.

Extract into an empty directory. The cryopulse-pXX directories must be siblings.
From that parent directory, run:

  python cryopulse-p39/scripts/reproduce_archive.py

This verifies all archived file hashes, recomputes the linkage and repeats the
dry and low-grip 130-degree stops. It does not rerun the complete nozzle-map
build, 41 driving conditions, CAD booleans or costly clearance/topology checks.

To recompute the driving study in full:

  python cryopulse-p39/scripts/reverse_study.py build
  python cryopulse-p39/scripts/reverse_study.py run
  python cryopulse-p39/scripts/reverse_study.py validate
  python cryopulse-p39/scripts/release_audit.py

To recompute the new camber CAD, use the stated environment values:

  CRYO_DUCT_VARIANT=camber CRYO_FRONT_DUCT_SHIFT_M=.17
  CRYO_REAR_DUCT_SHIFT_M=.15 CRYO_WHEEL_TRAVEL_ENVELOPE=1
  python cryopulse-p39/scripts/camber_ducts.py open

Set the four variables in the environment of that command. The generated model
uses 1:10 metre coordinates. It is a geometry proxy, not a fabrication drawing.
Then run camber_clearance_v2.py. The archived topology carrier is checked by
camber_connectivity.py p39-open-K0-U10 camber-duct-connectivity.json.

ANGLE CONVENTION
0 degrees: forward reaction / rear exhaust.
90 degrees: downward reaction / upward exhaust.
180 degrees: backward reaction / forward exhaust.
The network includes inlet capture momentum once, outlet pressure reaction and
angle-dependent duct loss. Every braking event starts at 130 degrees. The new
mean motion has finite rate and debits actuator work to the original shared DC
node. Above 160 degrees, the screening map is symmetric only. Jet recirculation,
external-pressure changes and mechanical travel remain unqualified.

CAMBER MECHANISM
The lower arm retains its length. An adjustable upper link sets camber while
vertical wheel-centre travel is prescribed. The calculation is a front
projection: toe, caster, a steering tie rod, driveshafts, hoses and structural
deflection need a complete three-dimensional mechanism. The sizing load is an
assumed 6 kNm camber moment, not an established road load. The screw-column
calculation is an ideal Euler screen. No production actuator is selected.

MATERIALS AND MEASUREMENT
Tyre compound, carcass, profile and tread need force tests at controlled load,
slip, pressure, temperature and surface condition. A silica-rich cold/wet
specification does not inherit the dry tyre's speed or grip results. PTFE-lined
spherical joints and tuned compliant mounts are candidates for different jobs.
No commercial material name is converted into an assumed grip increase.

The physical demonstration begins with a low-force geometry jig. A full-size
tyre facility then compares fixed and active camber with the same tyre, followed
by an alternative tyre specification, using randomised paired repeats and
conditions withheld from development. The website contains the diagrams and
the detailed evidence links. Primary references are in active-camber.json.

