{
  "title": "NASA Ames Run 15/16 measured-versus-modeled channel velocity response",
  "source": "Kato et al. (2004), AIAA 2004-0317, NASA NTRS 20040105526, printed pp. 5-6 (PDF pp. 5-6).",
  "source_url": "https://ntrs.nasa.gov/citations/20040105526",
  "source_pdf": "https://ntrs.nasa.gov/api/citations/20040105526/downloads/20040105526.pdf",
  "source_pdf_sha256": "3D89659A267AA245B4B7BA1034D2B535965CA4559F6A15FA52288CDF8543EA72",
  "quantity": "Difference in reported approximate increase in cross-section-averaged velocity: experimental percentage minus selected 2-D/3-D calculated percentage; percentage-point units.",
  "inputs_source_convention_percent": [
    {
      "run": "15",
      "series": "NASA Ames experiment",
      "value_percent": 27,
      "evidence": "reported experiment"
    },
    {
      "run": "15",
      "series": "2-D calculation",
      "value_percent": 26,
      "evidence": "reported calculation"
    },
    {
      "run": "15",
      "series": "3-D calculation",
      "value_percent": 26,
      "evidence": "reported calculation"
    },
    {
      "run": "16",
      "series": "NASA Ames experiment",
      "value_percent": 38,
      "evidence": "reported experiment"
    },
    {
      "run": "16",
      "series": "2-D calculation",
      "value_percent": 31,
      "evidence": "reported calculation"
    },
    {
      "run": "16",
      "series": "3-D calculation",
      "value_percent": 30,
      "evidence": "reported calculation"
    }
  ],
  "derived_differences": [
    {
      "run": "15",
      "comparison": "2-D",
      "experiment_increase_percent_source_decimal": 27,
      "model_increase_percent_source_decimal": 26,
      "experiment_minus_model_percentage_points_source_decimal": 1,
      "difference_exact_base12": "1"
    },
    {
      "run": "15",
      "comparison": "3-D",
      "experiment_increase_percent_source_decimal": 27,
      "model_increase_percent_source_decimal": 26,
      "experiment_minus_model_percentage_points_source_decimal": 1,
      "difference_exact_base12": "1"
    },
    {
      "run": "16",
      "comparison": "2-D",
      "experiment_increase_percent_source_decimal": 38,
      "model_increase_percent_source_decimal": 31,
      "experiment_minus_model_percentage_points_source_decimal": 7,
      "difference_exact_base12": "7"
    },
    {
      "run": "16",
      "comparison": "3-D",
      "experiment_increase_percent_source_decimal": 38,
      "model_increase_percent_source_decimal": 30,
      "experiment_minus_model_percentage_points_source_decimal": 8,
      "difference_exact_base12": "8"
    }
  ],
  "calculation": "For each selected comparison, subtract the article's approximate model increase from its approximate measured increase: Run 15, 27\u221226=1 percentage point for both 2-D and 3-D; Run 16, 38\u221231=7 points for 2-D and 38\u221230=8 points for 3-D.",
  "base12_check": "Differences 1, 7, and 8 are all single-digit values and therefore have the same numeral strings in base 12. The percentage inputs are transcribed as conventionally printed; base conversion changes representation only, not physical precision.",
  "reported_conditions": {
    "run15": "Total nozzle-entry pressure about 9.10\u00d710^5 Pa, total temperature 5560 K, conductivity 130 mho/m, applied magnetic field 0.92 T; selected comparison uses E_y=6000 V/m and the paper reports approximately 134 V electrode setting.",
    "run16": "Total nozzle-entry pressure about 9.92\u00d710^5 Pa, total temperature 5560 K, conductivity 140 mho/m, applied magnetic field 0.92 T; selected comparison uses E_y=7000 V/m and 380 V capacitor setting.",
    "both": "The paper reports about 1.2 ms steady flow. Runs are different conditions, and they are not treated as a controlled pair varying one factor alone. The original measurements were inferred from induced voltage at an unpowered last electrode pair; the paper notes this inherently averages the flow velocity profile."
  },
  "interpretation": "At the source's rounded values, Run 15 calculations are about 1 percentage point below the reported experimental increase. For Run 16, selected 2-D/3-D calculations are about 7/8 points below it. This is a descriptive comparison, not an uncertainty-normalized validation score or proof of model failure.",
  "limits": [
    "The source reports approximate values and no uncertainty bars, so the differences cannot be assigned statistical significance.",
    "The selected Runs 15 and 16 used different pressures, conductivities, capacitor settings and chosen electric fields; do not infer a single-variable trend between them.",
    "This is a component-scale laboratory channel comparison, not thrust, full energy closure, an MHD generator-to-accelerator loop, or vehicle performance."
  ],
  "reproduction": "python nasa-ames-run-model-gap.py",
  "new_physical_result_claimed": false
}