Stream/Sediment Settling Velocity (Stokes) 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

t5-080

Effect

Computation or source lookup only

Input and validation requirements

The specification has no turbulent-regime settling formula, so inputs beyond the low-Reynolds-number Stokes regime cannot produce a valid velocity. It also requires explicit rejection of zero viscosity and explicit sign/unit conventions.

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": {
    "grain_diameter_m": 0.00004,
    "grain_density_kg_per_m3": 2650,
    "fluid_density_kg_per_m3": 998,
    "viscosity_Pa_s": 0.001002,
    "gravity_m_per_s2": 9.80665
  },
  "expected_outputs": {
    "settling_velocity_m_per_s": 0.0014371777
  },
  "working": "Δρ=2650−998=1652 kg/m³. d=40 μm=4.0×10^-5 m, so d²=1.6×10^-9 m². Numerator=9.80665×1652×1.6×10^-9=2.592093728×10^-5. Denominator=18×0.001002=0.018036. v=(2.592093728×10^-5)/0.018036=0.0014371777 m/s."
}

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-tranche5/tranche5-results.json