{
  "citation": "Kaminaga, S.; Tomioka, S.; Yamasaki, H. Performance of Scramjet Engine with MHD Energy Bypass System. Journal of the Japan Society for Aeronautical and Space Sciences 53(623), 554–561 (2005). DOI 10.2322/jjsass.53.554.",
  "source_pdf": "https://www.jstage.jst.go.jp/article/jjsass/53/623/53_623_554/_pdf",
  "source_pdf_sha256": "91B18FBDA89B1308BD7397B36243BEB565EEF70715FF891A771568EE65B496BA",
  "figure": "Figure 12, printed p. 560 / PDF page 7; points were visually digitized from a locally rendered source PDF.",
  "digitization": {
    "interaction_parameter_step": 0.05,
    "normalized_thrust_y_axis": [
      0.95,
      1.05
    ],
    "visual_readout_tolerance": 0.002,
    "tolerance_meaning": "estimated image-reading tolerance only; not model uncertainty, experimental error, or confidence interval",
    "interpolation": "line segments are visual guides only; no interpolation or fit is claimed"
  },
  "conditions": {
    "flight_mach": 8,
    "altitude_context_km": 30,
    "inlet_static_pressure_kPa": 1.13,
    "inlet_static_temperature_K": 227,
    "inlet_contraction_ratio": 2.86,
    "inlet_capture_fraction": 1.0,
    "working_gas": "N2 78%, O2 21%, Ar 1%",
    "fuel": "H2",
    "equivalence_ratio": 1.0,
    "assumed_mhd_electrical_efficiency": 0.8,
    "assumed_accelerator_efficiency": 0.8,
    "combustor_minimum_mach": 1.1,
    "wall": "adiabatic",
    "combustion": "chemical equilibrium; mixing delay neglected",
    "power_routing": "all MHD generator electrical output is assigned to the downstream MHD accelerator"
  },
  "limits": [
    "steady quasi-one-dimensional numerical model, not a hardware test or flight",
    "oblique inlet shocks were not explicitly modeled; inlet capture was set to unity",
    "electrical/accelerator efficiencies are assumed model parameters, not measured efficiencies",
    "at s_gen=-0.40 the article reports choking after fuel addition and no useful thrust; its plotted cross is not assigned a digitized thrust value",
    "no external installation mass, complete auxiliary-power/vehicle balance, or mission comparison is established"
  ],
  "result": "The authors' prose describes the change in normalized net thrust as about 3%. Separately, approximate visual readings from Fig. 12 range from 0.977 to 1.036 of baseline, a 5.9 percentage-point peak-to-trough span. The readings are not exact source data; the prose summary and the graph's approximate min-to-max span are different descriptions and should not be conflated.",
  "approximate_figure_readout": {
    "minimum_normalized_thrust": 0.977,
    "maximum_normalized_thrust": 1.036,
    "peak_to_trough_percentage_points": 5.9,
    "status": "visual readings from published graph, not source tabular data"
  }
}