{
  "title": "HVEPS Figure 11: oxygen-enrichment design-property plot (graph-read redraw)",
  "source": "Lineberry et al., AFRL-PR-WP-TP-2007-233 / NTIS-NTRL ADA471429, Figure 11, PDF p.12 / printed p.10",
  "source_record": "https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/ADA471429.xhtml",
  "source_file_sha256": "ccbc90c0bc0626328b058023d153d2f268767f85dafd8bfd2a0dbffaccfa1521",
  "source_plot_class": "Published design calculations for planned UTRC scramjet-rig operation; not experimental measurement data.",
  "calculation_provenance": "The report says Table II was calculated using PWR RASCAL code with LyTec thermochemical code. It describes Figure 11 as design-level inlet conductivity and diagonal power-density parameters.",
  "digitization": "Four visible marker centres per efficiency series were read approximately from the source PDF raster at about 20, 25, 30 and 34.5 percent oxygen enrichment. Values are rounded to graph resolution; connecting lines are visual guides and do not represent newly calculated intermediate points.",
  "visual_read_allowance": {
    "oxygen_enrichment_percentage_points": 0.2,
    "conductivity_S_per_m": 0.2,
    "diagonal_power_density_MW_per_m3_per_T2": 0.01,
    "status": "Analyst visual-read allowances only; not source, instrument, or model uncertainty."
  },
  "series": {
    "conductivity": {
      "85% combustion efficiency": [
        0.8,
        3.9,
        6.8,
        8.0
      ],
      "95% combustion efficiency": [
        2.4,
        7.0,
        10.5,
        12.0
      ],
      "100% combustion efficiency": [
        4.5,
        10.2,
        14.0,
        15.6
      ]
    },
    "diagonal_power_density": {
      "85% combustion efficiency": [
        0.02,
        0.085,
        0.155,
        0.19
      ],
      "95% combustion efficiency": [
        0.05,
        0.16,
        0.255,
        0.3
      ],
      "100% combustion efficiency": [
        0.1,
        0.245,
        0.35,
        0.4
      ]
    }
  },
  "distinction_from_table_ii": "Table II gives target cases at 35% oxygen enrichment for 75%, 85% and 95% efficiency. Its 85% entry lists 8.06 S/m and a Faraday power-density parameter of 7.81 MW/m^3/T^2. Figure 11 instead plots approximate diagonal power density normalized by B^2 (about 0.19 MW/m^3/T^2 at the 34.5%, 85% design point); these are different power-density definitions and must not be conflated.",
  "design_point": "The report identifies 34.5% oxygen enrichment at 85% combustion efficiency as the selected MHD-channel mechanical design point. Table II is a calculated target table; it separately notes a March 2006 baseline measured mean combustion efficiency of 84%, an unseeded baseline result, not validation of Figure 11 curves.",
  "what_this_shows": "Why oxygen enrichment and combustion efficiency mattered when selecting an intended hot, conductive test flow.",
  "what_this_does_not_show": [
    "measured HVEPS electrical output",
    "measured MHD power-density values",
    "a validated reproduction of RASCAL or LyTec",
    "a flight result, net vehicle benefit, or closed generator-to-accelerator energy loop",
    "complete solver inputs, native pointwise model output, or propagated uncertainty"
  ],
  "reproduction": "python hveps-figure11-design-redraw.py",
  "source_graph_artwork_embedded": false,
  "rights_note": "This is an independently drawn approximate numerical redraw with attribution, not a copy of the source figure artwork. Public reuse rights for the source report figures have not been separately assessed."
}