{
  "case_id": "HX-S01",
  "status": "ANALYTICAL SCREEN; NOT EXPERIMENTAL TRUTH OR CFD ACCEPTANCE TARGET",
  "geometry_idealization": "Straight, fully developed semicircular duct; corrugation, entry development, headers and collectors omitted.",
  "inputs": {
    "diameter_m": 0.0025,
    "length_m": 0.24,
    "velocity_m_s": 0.246,
    "hot_inlet_K": 323.0,
    "cold_inlet_K": 293.0,
    "rho_kg_m3": 994.1,
    "mu_Pa_s": 0.0007196,
    "cp_J_kg_K": 4178.0,
    "k_water_W_m_K": 0.6221,
    "Pr": 4.833
  },
  "relations": {
    "area": "A = pi*D^2/8",
    "wetted_perimeter": "P = pi*D/2 + D",
    "hydraulic_diameter": "Dh = 4*A/P",
    "reynolds": "Re = rho*U*Dh/mu",
    "pressure_drop": "dP = f_D*(L/Dh)*(rho*U^2/2); laminar semicircle relation converted from Fanning to Darcy basis",
    "duty_screen": "Two fully-developed Nusselt asymptotes feed an idealized counterflow epsilon-NTU screen."
  },
  "predictions": {
    "hydraulic_diameter_m": 0.001527538675879143,
    "reynolds": 519.1181832019151,
    "straight_channel_pressure_drop_Pa": 576.1982000103136,
    "idealized_duty_band_W_per_pair": [27.461396898909808, 30.90061888206734],
    "nusselt_limits": [4.631, 5.626]
  },
  "limitations": [
    "The duty range is a two-correlation screening band, not a statistical uncertainty interval.",
    "The duct idealization does not represent the corrugated reconstructed geometry.",
    "No pointwise experiment match was established.",
    "Not used as a post-hoc acceptance target."
  ],
  "correlation_references": [
    {
      "title": "Hydrodynamically Developing and Fully Developed Laminar Flows in a Semicircular Duct: Analytical and Computational Analyses",
      "doi": "10.13182/NSE14-107",
      "url": "https://wx1.ans.org/pubs/journals/nse/a_38310"
    },
    {
      "title": "Laminar flow heat transfer in a semi-circular tube with uniform wall temperature",
      "doi": "10.1016/0017-9310(88)90044-0",
      "url": "https://doi.org/10.1016/0017-9310(88)90044-0"
    }
  ]
}