Fluid Property Lookup (Water/Air/Common Fluids)

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Thermodynamics, Fluids & Aero

Tranche

tranche-7

Evidence ID

t7-115

Ledger rows

1

No ledger note is attached.

Review findings

Core derived-property formulas and lookup interpolation are standard, but the instrument needs an explicit table schema: fluid identity and composition, phase, pressure basis, temperature range, interpolation rule, source edition, and behavior at phase boundaries. Verdict is NEEDS_REVIEW because the current specification does not define those constraints or resolve the conflicting saturation/1 atm convention.

Formula and scope findings

• Table interpolation is a valid method only between explicitly tabulated temperatures and under the same pressure/phase conditions; the interpolation rule is not specified, so linear interpolation must be declared as an assumption.
• Kinematic viscosity must be computed as ν = μ/ρ, and Prandtl number as Pr = μ cp/k; the specification does not explicitly state these derived formulas.
• Gas properties require a defined pressure model or pressure-specific tables. Temperature alone is insufficient for density, and pressure can also affect other properties.
• The supported fluid list, valid temperature ranges, phase boundaries, and saturation-versus-single-pressure conventions are unspecified.
• Near phase changes, properties can be discontinuous or strongly nonlinear, so unrestricted interpolation can produce invalid values.

Unit assumptions

• Temperature inputs are in kelvin unless explicitly labeled in degrees Celsius; the vectors below label temperature units to remove ambiguity.
• Pressure is absolute pressure in pascals; 1 atm = 101325 Pa exactly for these vectors.
• Density ρ is in kg/m^3, dynamic viscosity μ is in Pa·s, kinematic viscosity ν is in m^2/s, thermal conductivity k is in W/(m·K), and specific heat cp is in J/(kg·K).
• Prandtl number is dimensionless and calculated as Pr = μ cp/k.
• The air entries are dry-air values at approximately 1 atm; the water entries are liquid-water values except the 100 °C entry, which is at saturation pressure.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

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.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "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."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json