Public evidence

physics.fluid.colebrook

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

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Verification

9/9 calculation tests · Production surface contract 4/4

Golden tests 1 / 1
Boundary tests 5 / 5
Property tests 3 / 3
Production surface contract 4 / 4
Engine tested Yes
Source checked Yes
Artifact integrity PASS
Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract PASS
Evidence attested at 2026-09-16T06:44:24.203Z
Last production check 2026-09-16T06:44:24.203Z
Public / cache —
Origin —
Supplemental domain review Not performed
Named expert review Not performed

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS

Fingerprint sha256:d9eae29ee96f8f982c9d408d79a6592f0f95df4fb4080138a201f8026c96821a

Input schema sha256:3e523ba459b82af86a656a663688e2321e8b4a9592f9c1c2ff0745ff4ee5f09f · Output schema sha256:cd6d361ae837cd914f7c599c1f47a85cac544494a582e3e14d95dcd625ed27f8 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: colebrook
Engine: colebrook
Engine build: 2026-09-16
Evidence core: 2026-09-16T08:17:21.133Z
Rendered: 2026-09-16T08:32:57.042Z
Last reviewed: —

Assumptions

Turbulent circular full-flow pipe, Re ≥ 4000
Incompressible; constant properties
Not laminar 64/Re
Not a Moody-chart lookup
Does not compose Darcy head loss or Reynolds

Limitations

Turbulent pipes Re ≥ 4000 — not laminar f=64/Re
Not a Moody-chart lookup
Does not compose Darcy–Weisbach head loss

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

Colebrook, C.F. (1939). Turbulent flow in pipes, with particular reference to the transition region between the smooth and rough pipe laws — Journal of the Institution of Civil Engineers, 11, 133–156
Supports: 1/√f = −2 log10(ε/D/3.7 + 2.51/(Re √f))
White, F.M. Fluid Mechanics — pipe flow friction — Colebrook–White equation
Supports: Implicit turbulent-pipe friction factor; not laminar 64/Re

Published checks

Golden, boundary, and property cases included in this evidence build.

ID	Kind	Status	Detail
`golden-colebrook`	golden	pass	Expected f=0.01900543522195957 · Re=100000 · rel_roughness=0.0002 · model=colebrook_white · Actual f=0.01900543522195957 · Re=100000 · rel_roughness=0.0002 · inv_sqrt_f=7.253725059348281 · model=colebrook_white
`boundary-colebrook`	boundary	pass	Expected f=0.01900543522195957 · Actual f=0.01900543522195957 · Re=100000 · rel_roughness=0.0002 · inv_sqrt_f=7.253725059348281 · model=colebrook_white
`boundary-colebrook-eps`	boundary	pass	Expected f=0.01900543522195957 · rel_roughness=0.0002 · Actual f=0.01900543522195957 · Re=100000 · rel_roughness=0.0002 · inv_sqrt_f=7.253725059348281 · model=colebrook_white
`boundary-colebrook-re`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-colebrook-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`boundary-colebrook-mixed`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`property-colebrook-residual`	property	pass	g≈0
`property-colebrook-eps`	property	pass	ε/D
`property-colebrook-model`	property	pass	colebrook_white