{
  "title": "MHD propulsion evidence and boundary matrix",
  "version": 1,
  "prepared": "2026-10-01",
  "purpose": "Classify cited MHD propulsion records by evidence type, system boundary, source-input availability, uncertainty status, and permitted inference. This is an evidence map, not a matched quantitative performance comparison.",
  "method": {
    "selection": "Ten MHD propulsion cases already present in the project's bounded priority literature audit: cycle models, a modeled ionizer/generator case, component experiments, a facility design, and recent simulations.",
    "evidence_policy": "Keep reported measurements, source-reduced measurements, calculations, simulations, facility design predictions, abstract-only findings, and this project's approximate graph readings separate.",
    "boundary_policy": "Record the source's named component/cycle and output plane. Do not sum or rank values across different architectures or operating conditions.",
    "uncertainty_policy": "State only what the inspected record reports. 'Not reported/located' describes the bounded record check, not proof that no data exist elsewhere.",
    "data_availability_check": "NASA NTRS records for the 2000 and 2011 reports were rechecked; neither record displayed a linked model/data supplement. The official HVEPS ADA471429 NTIS/NTRL report record and PDF are retained and linked (official PDF SHA-256 CCBC90C0BC0626328B058023D153D2F268767F85DAFD8BFD2A0DBFFACCFA1521). Direct visual comparison with the retained third-party color copy was limited to Table VI, printed p. 27 / PDF p. 29; the whole report was not re-compared. AIAA DOI/Crossref metadata did not expose supplementary-data relations for the inspected HVEPS proceedings records.",
    "limits": [
      "The studies use different architectures, station definitions, flow conditions, outputs and model assumptions.",
      "This matrix cannot establish a common-boundary net-thrust result or scientific novelty.",
      "The literature/supplement search is bounded and is not exhaustive.",
      "Reported absence of a file in an inspected record does not establish that it is unavailable from every archive or author."
    ],
    "regeneration": "The CSV is a human-readable companion export of the rows in this JSON. It can be checked against the table and each linked source record; no plotted values are generated by this matrix."
  },
  "cases": [
    {
      "case_id": "nasa-2000-cycle",
      "reference": "Litchford et al. NASA/TP-2000-210387 (2000)",
      "url": "https://ntrs.nasa.gov/citations/20000095934",
      "evidence_class": "analytical thermodynamic-cycle model",
      "boundary": "Simplified inlet-to-generator-to-combustor-to-accelerator/nozzle cycle; outputs depend on chosen extraction/addition and component-efficiency assumptions",
      "source_inputs": "Public NASA report equations, assumptions and figures; project has an approximate figure reconstruction",
      "data_and_uncertainty": "No pointwise source table or author code surfaced in inspected record; no statistical uncertainty package; historical discrepancy claim withdrawn because curve identity was not established; approximate figure readings do not establish a mismatch with NASA numerical results",
      "supports": "A bounded equation-based reconstruction of the published model",
      "does_not_establish": "Validated hardware, a matched comparison with other architectures, or whole-vehicle benefit"
    },
    {
      "case_id": "nasa-2001-ionizer",
      "reference": "Park et al. NASA NTRS 20010066491 (2001)",
      "url": "https://ntrs.nasa.gov/citations/20010066491",
      "evidence_class": "analytical one-dimensional modeled case",
      "boundary": "External ionizer demand 827 MW compared with gross generator output 151 MW for one stated case; 100%-efficient ionizer assumption",
      "source_inputs": "Source PDF Table 1; retained and checksummed in project; values transcribed from the source",
      "data_and_uncertainty": "No test measurement; source provides a single modeled comparison, not a full vehicle electrical bus or uncertainty budget",
      "supports": "That modeled ionizer demand exceeds gross generator output by about 5.48 times under that case's assumptions",
      "does_not_establish": "Universal failure of every architecture, net aircraft thrust, or measured generator performance"
    },
    {
      "case_id": "nasa-2011-npss",
      "reference": "Benyo NASA/TM-2011-217136 (2011)",
      "url": "https://ntrs.nasa.gov/citations/20110015567",
      "evidence_class": "coupled turbojet-cycle NPSS model",
      "boundary": "Turbojet plus pre-ionizer, MHD generator and accelerator; report gives plotted extracted-power predictions and selected prose assumptions",
      "source_inputs": "Public NASA PDF, equations, prose and plotted curves; approximate plot readings and an independent consistency calculation",
      "data_and_uncertainty": "NTRS record showed only report PDF; no NPSS deck, pointwise result file or uncertainty file surfaced; apparent prose/plot mismatch remains unresolved",
      "supports": "A bounded audit of published statements and a reproducibility question",
      "does_not_establish": "Exact NPSS reproduction, confirmed source error, or hypersonic scramjet flight benefit"
    },
    {
      "case_id": "riggins-2004-cycle",
      "reference": "Riggins (2004), Journal of Propulsion and Power",
      "url": "https://doi.org/10.2514/1.4980",
      "evidence_class": "thermally balanced modeled cycle (abstract-level in this audit)",
      "boundary": "Abstract describes MHD-bypass versus conventional scramjet performance over Mach 8–12.2 and identifies modeled irreversibility/cooling and total-pressure losses",
      "source_inputs": "Publisher/host record and abstract; numerical curves were not available to this audit",
      "data_and_uncertainty": "Full paper data and uncertainty details not inspected here; no numerical reconstruction claimed",
      "supports": "That published modeling reports configuration-specific performance penalties",
      "does_not_establish": "Exact quantitative reproduction or that the result applies to all configurations"
    },
    {
      "case_id": "kaminaga-2005",
      "reference": "Kaminaga et al. (2005)",
      "url": "https://doi.org/10.2322/jjsass.53.554",
      "evidence_class": "steady quasi-one-dimensional numerical scramjet comparison",
      "boundary": "Modeled generator braking, combustion pressure contribution, wall friction and accelerator routing; Figure 12 shows normalized net-thrust variation",
      "source_inputs": "Full article and source graph; project values are approximate graph readings, not tabulated source data",
      "data_and_uncertainty": "Plot-reading tolerance estimated; source does not provide pointwise data or a complete model uncertainty budget",
      "supports": "A source-attributed example of competing modeled force contributions under stated assumptions",
      "does_not_establish": "Experimental validation, general performance trends beyond the modeled case, or flight benefit"
    },
    {
      "case_id": "hveps-2007",
      "reference": "AFRL HVEPS report ADA471429",
      "url": "https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/ADA471429.xhtml",
      "evidence_class": "short-duration component ground test",
      "boundary": "Downstream MHD generator on a Mach-8-simulating combustor exhaust; Test 3 distinguishes 6.52 kW load-bank dissipation, 14.38 kW post-test active-channel estimate and 14.80 kW matched-load calculation",
      "source_inputs": "Official NTIS/NTRL ADA471429 report PDF retained (SHA-256 CCBC90C0BC0626328B058023D153D2F268767F85DAFD8BFD2A0DBFFACCFA1521); direct comparison with the retained third-party color copy was limited to Table VI, printed p. 27 / PDF p. 29. Whole-report comparison is not claimed",
      "data_and_uncertainty": "Table VI values and matched rows were checked against both copies; raw synchronized telemetry, calibration files and a full uncertainty budget were not located in the report. The third-party copy remains the source of color figure crops; the official NTIS/NTRL record is the official report source",
      "supports": "That an MHD generator component produced reported electrical output in a ground rig",
      "does_not_establish": "A generator-to-accelerator loop, aircraft power-bus closure, or net flight thrust"
    },
    {
      "case_id": "nasa-ames-2004-accelerator",
      "reference": "Kato et al. NASA NTRS 20040105526",
      "url": "https://ntrs.nasa.gov/citations/20040105526",
      "evidence_class": "short-duration accelerator-channel experiments plus separate simulations",
      "boundary": "Two laboratory runs report about 27% and 38% averaged-flow velocity increase; later 2-D/3-D calculations report separate estimates",
      "source_inputs": "NASA-hosted conference paper; site figure transcribes approximate values from its text",
      "data_and_uncertainty": "About 1.2 ms steady flow; source does not report uncertainty bars; do not conflate measured runs with calculated values",
      "supports": "That externally powered fields accelerated gas inside the tested channel under those conditions",
      "does_not_establish": "An electricity-generating component, closed recovery loop, or vehicle net thrust"
    },
    {
      "case_id": "mapx-facility",
      "reference": "NASA MAPX NASA/TP-2003-212285 and 2008 status record",
      "url": "https://ntrs.nasa.gov/citations/20030025730",
      "evidence_class": "facility design prediction and status record",
      "boundary": "Design report lists 1.3 MW applied input, 61 kW predicted MHD push work and roughly 150% calculated velocity augmentation; 2008 record describes preliminary tests/progress",
      "source_inputs": "NASA facility-design report and later NASA status record",
      "data_and_uncertainty": "The listed design values are predictions, not measured completed-run performance; inspected status record supplies no quantitative full-up result",
      "supports": "The planned scope and modeled design point of a separately powered research facility",
      "does_not_establish": "Measured 150% augmentation, a self-powered loop, or HVEPS/aircraft validation"
    },
    {
      "case_id": "ling-2024",
      "reference": "Ling et al. (2024)",
      "url": "https://doi.org/10.13675/j.cnki.tjjs.2205028",
      "evidence_class": "MHD channel simulation (publisher abstract only in this audit)",
      "boundary": "Abstract reports distinct generation-efficiency and enthalpy-extraction series for 1–4 T cases",
      "source_inputs": "Publisher abstract transcription; full definitions and model inputs not independently audited here",
      "data_and_uncertainty": "No experimental measurement or uncertainty propagation reproduced; full-paper model details remain to be checked",
      "supports": "That a published model reports field-dependent channel quantities",
      "does_not_establish": "Measured engine output or overall engine efficiency"
    },
    {
      "case_id": "liu-2025",
      "reference": "Liu, Wu & Meng (2025)",
      "url": "https://www.spacejournal.cn/zkydw/en/article/id/7ba55439-82c5-4689-9788-7d7ed496ce35",
      "evidence_class": "zero-dimensional scramjet model with analytical post-combustor MHD extraction; selected publisher-indexed PDF text audited",
      "boundary": "At 2.5 T and load factor 0.4, model reports Isp penalties of 3.58% at 0.5% enthalpy extraction and 6.43% at 0.9%",
      "source_inputs": "Baseline comparison: one Mach-7, approximately 29.16-km combustor test point; MHD module: analytical channel equations, compared with a single CFD channel case, not an MHD experiment",
      "data_and_uncertainty": "Baseline isolator errors reported up to 17.28% in static pressure; MHD CFD comparison uses one 80-mm channel, three electrode pairs and nominal 8 S/m conductivity. No uncertainty propagation or independent reproduction here. Direct PDF fetch was blocked; selected page text was available through publisher indexing.",
      "supports": "Configuration-specific model predictions and the paper's split validation scope",
      "does_not_establish": "Measured MHD-generator output, experimental validation of the MHD module, closed-loop reinjection, net vehicle power or thrust benefit"
    }
  ]
}