Fluid Property Lookup (Water/Air/Common Fluids) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-115

Effect

Computation or source lookup only

Input and validation requirements

The specification does not define a pressure-validity rule, phase-selection rule, or absolute-versus-gauge pressure convention. Zero absolute pressure produces zero density and an undefined kinematic viscosity, while the saturation branch is non-unique at the phase switch unless phase or quality is supplied.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "fluid": "water",
    "temperature": 20,
    "temperature_unit": "degC",
    "pressure": 101325,
    "pressure_unit": "Pa",
    "phase": "liquid"
  },
  "expected_outputs": {
    "rho_kg_m3": 998.2,
    "mu_Pa_s": 0.001002,
    "nu_m2_s": 0.00000100381,
    "k_W_mK": 0.598,
    "cp_J_kgK": 4182,
    "Pr": 7.0073
  },
  "reference_data": {
    "temperature_C": 20,
    "rho_kg_m3": 998.2,
    "mu_Pa_s": 0.001002,
    "k_W_mK": 0.598,
    "cp_J_kgK": 4182,
    "pressure_Pa": 101325,
    "source_convention": "Widely tabulated standard liquid-water property values; Incropera thermophysical-property tables, approximately 20 degC and 1 atm"
  },
  "working": "ν = μ/ρ = 0.001002 Pa·s / 998.2 kg/m^3 = 1.00381×10^-6 m^2/s. Pr = μ cp/k = (0.001002×4182)/0.598 = 4.190364/0.598 = 7.0073."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json