{
  "note": "HYPOTHETICAL design study. Changes parameters only; the simulator equations and the measured polar are unchanged. No bird value anywhere.",
  "sources": {
    "real_fish": {
      "mass_kg": 0.06,
      "ref_area_m2": 0.012687999999999998,
      "span_m": 0.261,
      "AR": 10.7,
      "CL_max": 0.78,
      "LD_max": 4.37,
      "CD_min": 0.055,
      "kind": "measured",
      "source": "park-choi-2010 Tables 1 and 2 (model L3)"
    },
    "bat_flight_muscle_fraction": {
      "mean": 0.0913,
      "min": 0.078,
      "kind": "secondary",
      "source": "PMC10966098 (Onychonycteris paper, 10.1038/s42003-024-06032-9) citing Bullen and McKenzie 2004: flight muscle on average 9.13 % of body mass in extant bats, minimum 7.8 %"
    },
    "bat_mech_power_W": {
      "mean": 0.092,
      "max": 0.14,
      "min": 0.046,
      "body_mass_kg": 0.0076,
      "kind": "measured",
      "source": "PMC10154928 (10.1098/rspb.2023.0045): Pipistrellus nathusii, 7.6 +- 0.8 g, estimated mechanical power 0.046 to 0.140 W, mean 0.092 W, from aerodynamic measurement"
    },
    "bat_conversion_efficiency": {
      "low": 0.07,
      "high": 0.104,
      "kind": "measured",
      "source": "PMC10154928: conversion efficiency 7.0 to 10.4 % increasing with speed in P. nathusii"
    },
    "bat_metabolic_power_per_weight_W_per_N": {
      "min": 7.1,
      "max": 18.7,
      "kind": "measured",
      "source": "PMC10154928: weight-specific metabolic power 7.1 to 18.7 W per N"
    },
    "bat_inertial_power_W_per_kg": {
      "value": 8,
      "kind": "secondary",
      "source": "PMC9490335 (10.1098/rsif.2022.0315): inertial power about 8 W/kg, roughly independent of speed (Cynopterus brachyotis model); 6 to 7 W/kg in Plecotus and Glossophaga per Norberg"
    },
    "bat_wing_loading_N_m2": {
      "low": 6.5,
      "high": 14.25,
      "kind": "secondary-compilation",
      "source": "physics/comparison-data.csv (span-efficiency compilation): Plecotus auritus 6.5, Glossophaga soricina 11.05, Leptonycteris yerbabuenae 14.25 N/m2"
    },
    "pterosaur_hatchling": {
      "wing_loading_N_m2": [
        15.83,
        17.88
      ],
      "AR": [
        6.1,
        6.5
      ],
      "kind": "modelled",
      "source": "PMC8298463 (10.1038/s41598-021-92499-z): hatchling pterosaur wing loading 15.83 to 17.88 N/m2, aspect ratio 6.1 to 6.5 (modelled from fossils); Draco 22.7 to 24.2 N/m2 quoted there"
    },
    "bumblebee_hover_metabolic_W_per_kg": {
      "value": 559,
      "efficiency": [
        0.073,
        0.147
      ],
      "kind": "measured",
      "source": "PMC12606204 (10.1098/rsbl.2025.0325): hovering metabolic power 559 W/kg body; overall efficiency 7.3 to 14.7 %"
    },
    "oxycaloric_J_per_ml_O2": {
      "value": 20.1,
      "kind": "standard",
      "source": "oxycaloric equivalent for mixed substrate; the bumblebee paper uses 21.1 J per ml CO2 for carbohydrate"
    },
    "bird_values": {
      "kind": "unavailable (holdout)",
      "source": "class Aves is the frozen holdout; no bird parameter, comparison or figure is used"
    }
  },
  "bat_muscle_specific_power_derived_W_per_kg": {
    "mean": 132.58776733729175,
    "max": 201.76399377413964
  },
  "design": {
    "label": "HYPOTHETICAL truly-flying fish F1 (design study)",
    "hypothetical": true,
    "mass_kg": {
      "value": 0.06,
      "changed": false,
      "reason": "same body; the question is what fins and muscle a 60 g fish would need"
    },
    "wing_loading_N_m2": {
      "value": 12.0,
      "changed": true,
      "from": 46.39029003783103,
      "reason": "inside the bat range 6.5 to 14.25 N/m2 and below the pterosaur hatchling 15.8 to 17.9; chosen, not optimised"
    },
    "lifting_area_m2": {
      "value": 0.04905,
      "changed": true,
      "from": 0.012687999999999998
    },
    "aspect_ratio": {
      "value": 9.0,
      "changed": false,
      "from": 10.7,
      "reason": "kept at the fish value (9.0 to 10.7 in Park and Choi), which already lies in the powered-flier range the pterosaur paper quotes (6.1 to 6.5 for hatchlings; \"avian 5 to 12\" is a bird figure and is NOT used)"
    },
    "span_m": {
      "value": 0.664417037710503,
      "changed": true,
      "from": 0.261
    },
    "CL_max": {
      "value": 0.78,
      "changed": false,
      "reason": "same fin section; measured"
    },
    "LD_max": {
      "value": 4.37,
      "changed": false,
      "reason": "same measured polar (conservative: bats are not assumed better)"
    },
    "flight_muscle_fraction": {
      "value": 0.16,
      "changed": true,
      "from": "not reported for flying fish (Davenport 1992: red axial muscle no more than mackerel)",
      "reason": "see power budget: 0.16 is the smallest fraction that covers a 1 m/s climb at the bat-derived MAX specific power (0.15 falls 0.05 W short); it is ABOVE the bat mean (9.1 %) and minimum (7.8 %); the bat maximum is not in the fetched sources; at the bat MEAN specific power even 0.16 only just fails level flight"
    },
    "muscle_specific_mech_power_W_per_kg": {
      "value": 201.76399377413964,
      "range": [
        132.58776733729175,
        201.76399377413964
      ],
      "changed": "new",
      "kind": "derived",
      "reason": "P. nathusii mechanical power 0.140 W (max) over its flight muscle 7.6 g x 9.13 % = 0.69 g: 202 W/kg muscle (mean 133); a derived figure from two sourced numbers, and the chain may replace it"
    },
    "conversion_efficiency": {
      "value": 0.1,
      "range": {
        "low": 0.07,
        "high": 0.104,
        "kind": "measured",
        "source": "PMC10154928: conversion efficiency 7.0 to 10.4 % increasing with speed in P. nathusii"
      },
      "changed": "new",
      "reason": "top of the bat-measured range; bumblebee 7 to 15 %"
    }
  },
  "power_budget": {
    "v_min_m_s": 5.011760110325881,
    "P_req_table": [
      {
        "v_m_s": 5.011760110325881,
        "P_req_level_W": null,
        "P_req_climb_1_m_s_W": null
      },
      {
        "v_m_s": 6,
        "P_req_level_W": 1.2757578394071358,
        "P_req_climb_1_m_s_W": 1.8643578394071358
      },
      {
        "v_m_s": 7,
        "P_req_level_W": 1.4229168511882593,
        "P_req_climb_1_m_s_W": 2.0115168511882593
      },
      {
        "v_m_s": 8,
        "P_req_level_W": 1.6551485358053517,
        "P_req_climb_1_m_s_W": 2.2437485358053517
      },
      {
        "v_m_s": 10,
        "P_req_level_W": 2.3956791836442815,
        "P_req_climb_1_m_s_W": 2.9842791836442815
      },
      {
        "v_m_s": 12,
        "P_req_level_W": 3.5547213572035683,
        "P_req_climb_1_m_s_W": 4.143321357203568
      }
    ],
    "P_req_min_level_W": 1.2757578394071358,
    "P_req_min_climb_1_m_s_W": 1.8643578394071358,
    "P_avail_W_at_design_fraction": {
      "max_specific": 1.9369343402317403,
      "mean_specific": 1.2728425664380008
    },
    "P_avail_W_at_bat_mean_fraction": 1.105263157894737,
    "verdict_mechanical": "design fraction 0.16 covers level flight and a 1 m/s climb at the bat-derived MAX specific power",
    "verdict_bat_like": "a 60 g fish with the bat MEAN muscle fraction (9.1 %) could NOT fly level at the bat-derived max specific power, and could NOT climb at 1 m/s",
    "metabolic_power_W_for_climb": 18.64357839407136,
    "metabolic_W_per_kg_body": 310.726306567856,
    "compare": {
      "bat_metabolic_W_per_kg_body_range": [
        69.651,
        183.447
      ],
      "bumblebee_hover_W_per_kg": 559
    },
    "O2_demand_ml_per_s": 0.9275412136353909,
    "O2_demand_ml_per_min_per_kg": 927.5412136353909,
    "physiology_note": "The O2 demand is what the gill, haemoglobin and cardiac modules must supply for SUSTAINED flight; whether any gill can is for the physiology chain and the Lean O2-to-power bound. Burst (anaerobic) flight for seconds is a separate question. The real fish, per Davenport 1992, has no more red axial muscle than a mackerel."
  },
  "parameter_diff_real_to_flier": {
    "lifting_area_m2": [
      0.012687999999999998,
      0.04905
    ],
    "wing_loading_N_m2": [
      46.39029003783103,
      12.0
    ],
    "span_m": [
      0.261,
      0.664417037710503
    ],
    "aspect_ratio": [
      10.7,
      9.0
    ],
    "flight_muscle_fraction": [
      "unknown (small)",
      0.16
    ],
    "muscle_specific_mech_power_W_per_kg": [
      "unknown",
      201.76399377413964
    ],
    "conversion_efficiency": [
      "unknown",
      0.1
    ],
    "O2_delivery_ml_per_min_per_kg_required": [
      "unknown",
      927.5412136353909
    ],
    "mass_kg": [
      0.06,
      0.06
    ],
    "CL_max": [
      0.78,
      0.78
    ],
    "LD_max": [
      4.37,
      4.37
    ]
  },
  "what_this_does_not_establish": [
    "that such a fish could develop (development is not simulated)",
    "that fins of 4x area at the same section keep the measured polar",
    "that any gill can deliver the O2 (physiology chain pending)",
    "anything about birds (holdout)"
  ]
}