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

instrument mechanism / verified-clean

# Dimensionless Numbers Panel mechanism

The inspectable method record for Dimensionless Numbers Panel, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The six supplied formulas are standard, but the instrument claims ten dimensionless groups and provides only six formulas. Because four claimed outputs are undefined and regime interpretation lacks rules, the catalog entry fails verification. The honest_label field is empty and should disclose the missing Nu/Gr/Ra/Bi models and required inputs.

- The stated computation includes Nu, Gr, Ra, and Bi, but formulas for all four are missing.

- Nu cannot be computed from the listed raw properties alone without a specified correlation or measured heat-transfer coefficient; a common definition is Nu=hL_c/k.

- Gr formula is missing; a standard form is Gr=gβΔTL^3/ν^2, where ν=μ/ρ.

- Ra formula is missing; a standard form is Ra=GrPr=gβΔTL^3/(να).

- Bi formula is missing; a standard form is Bi=hL_c/k. The characteristic length must be specified.

- The supplied formulas for Re, Pr, We, Fr, Ma, and Fo are standard under the stated unit and variable assumptions.

## Units and conventions

- Use a fully consistent unit system; the test calculations use SI units: ρ in kg/m^3, V in m/s, L in m, μ in Pa·s, cp in J/(kg·K), k in W/(m·K), σ in N/m, g in m/s^2, a in m/s, α in m^2/s, and t in s.

- For Re, L is the characteristic length and μ is dynamic viscosity.

- For Pr, cp must be mass-specific heat capacity and k must be thermal conductivity.

- For We, σ is surface tension and L is the relevant characteristic length.

- For Fr, g and L must use compatible units and gL must be nonnegative; the selected characteristic length must be defined.

- For Ma, a is the local speed of sound in the same velocity units as V.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "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."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

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.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/dimensionless-numbers-panel/implementation/>)[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`

- `BOUNDARY_HAZARD_CATALOG.json`