{
  "revision": "P3.1 first physical demonstration specification",
  "purpose": "Measure whether cooling increases mass flow through identical duct hardware at matched driving total-pressure head, then account for heat and electrical resources.",
  "geometry_scale": 0.1,
  "air_speed_target_ms": 10.0,
  "cold_reservoir_K": 273.15,
  "initial_ice_mass_kg_assumed": 1.0,
  "ice_fusion_heat_Jkg_reference": 333550,
  "heat_exchanger_UA_WK_assumed": 8.0,
  "maximum_drive_head_difference_Pa": 0.2,
  "maximum_inlet_temperature_difference_K": 0.3,
  "minimum_paired_blocks": 6,
  "dry_air_dewpoint_max_K": 268.15,
  "sequence": "Six or more paired steady blocks, randomised AB/BA order. Same installed heat exchanger and neutral rotor setting. Warm reference and ice-water cold treatment, with drive head controlled rather than assumed from blower voltage.",
  "measurement_channels": ["calibrated mass flow", "inlet/outlet absolute temperature", "ambient pressure", "upstream total-pressure head", "exchanger differential pressure", "source DC voltage and current", "bath temperature", "melt mass and elapsed time", "inlet dewpoint"],
  "success_rule": "First verify control limits and calibration provenance. Report a positive paired mass-flow difference only if its conservative 95 percent interval excludes zero. Separately report cold duty, blower input, and calorimetric uncertainty. This result does not establish net vehicle thrust or self-recharging.",
  "materials": "New unused, traceable duct shells; smooth bonded joints; aluminium heat-exchanger insert isolated from composite where appropriate; transparent low-pressure observation section; rated low-voltage blower and current-limited supply; calibrated instruments. No material performance or prices are assumed from branding.",
  "first_stage_scope": "Ambient-pressure throughflow with an ice-water bath. No liquid nitrogen, oxidiser, sealed freezing-pressure vessel or road deployment is needed for this first test.",
  "limits": ["The 1:10 demonstration does not match vehicle Reynolds number or installed moving-road flow.", "UA, loss coefficient and predicted signal are design assumptions until measured.", "A larger volumetric flow or mass flow is not by itself an energy-efficiency or propulsion result.", "Use an independently calibrated flow measurement. Inferring all outputs from the same model would be circular."]
}