Source: https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/implementation/

instrument implementation / implementation-contract

# Dimensionless Numbers Panel implementation

A source-bound implementation contract for Dimensionless Numbers Panel; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## 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**: t5-022

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero viscosity input makes the Reynolds-number denominator vanish; without explicit validation, the plain-arithmetic engine can return Infinity instead of rejecting the input. The signed-velocity probe also exposes an undocumented convention that can change the reported Reynolds number from +1,000,000 to -1,000,000.

## 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": {
    "rho_kg_m3": 998,
    "V_m_s": 2,
    "L_m": 0.05,
    "mu_Pa_s": 0.001,
    "cp_J_kgK": 4180,
    "k_W_mK": 0.6,
    "sigma_N_m": 0.072,
    "g_m_s2": 9.81,
    "a_m_s": 343,
    "alpha_m2_s": 1.43e-7,
    "t_s": 100
  },
  "expected_outputs": {
    "Re": 99800,
    "Pr": 6.9666666667,
    "We": 2772.2222222222,
    "Fr": 2.855686,
    "Ma": 0.0058309038,
    "Fo": 0.00572
  },
  "working": "Re=(998×2×0.05)/0.001=99.8/0.001=99,800. Pr=(4180×0.001)/0.6=4.18/0.6=6.9666666667. We=(998×2^2×0.05)/0.072=(998×4×0.05)/0.072=199.6/0.072=2772.2222222222. Fr=2/√(9.81×0.05)=2/√0.4905=2/0.700357≈2.855686. Ma=2/343=0.0058309038. Fo=(1.43×10^-7×100)/(0.05^2)=1.43×10^-5/0.0025=0.00572."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/qualification/>)

## 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`