Public evidence

physics.fluid.darcy_weisbach

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

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Verification

11/11 calculation tests · Production surface contract 4/4

Golden tests 1 / 1
Boundary tests 5 / 5
Property tests 5 / 5
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Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status PASS (0 stale; 164 CURRENT) @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 sha256:655d4f1d3377c1b4af69e54ceeb465a0ba9e08330df9033b2d627bd8c40bf9df

Input schema sha256:87a5120e0303b9bef2ee820592411248e0e9ab8fcca99ecc1fd7b70c07a3939c · Output schema sha256:facaec23d012cbdcfe4ff878408123158e08e664d0f509ad52d2624349669601 · 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: darcy-weisbach
Engine: darcy-weisbach
Engine build: 2026-09-16
Evidence core: 2026-09-16T10:36:28.830Z
Rendered: 2026-09-16T11:29:50.771Z
Last reviewed: —

Assumptions

Incompressible
Constant Darcy friction factor
Circular full-flow pipe
g = 9.80665 m/s² unless given
Does not solve Colebrook for f
Not Hazen–Williams or minor-loss K

Limitations

Incompressible; constant Darcy friction factor; circular pipe
Does not solve Colebrook for f
Not Hazen–Williams, not minor-loss K v²/2g
Not volumetric flow Q=Av

Sources

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

ISO 80000-4 — Mechanics — Pressure and hydraulic head
Supports: Δp = ρ g hf for a hydrostatic/hydraulic head
White, F.M. Fluid Mechanics — pipe flow — Darcy–Weisbach equation
Supports: hf = f L v² / (2 g D) for circular pipes

Published checks

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

ID	Kind	Status	Detail
`golden-dw`	golden	pass	Expected dP_Pa=4000 · hf_m=0.4078864851911713 · model=darcy_weisbach · Actual hf_m=0.4078864851911713 · dP_Pa=4000 · f=0.02 · L=10 · v=2 · D=0.1 · rho=1000 · g=9.80665
`boundary-dw-zero-f`	boundary	pass	Expected dP_Pa=0 · hf_m=0 · Actual hf_m=0 · dP_Pa=0 · f=0 · L=10 · v=2 · D=0.1 · rho=1000 · g=9.80665
`boundary-dw-g`	boundary	pass	Expected hf_m=0.4 · dP_Pa=4000 · Actual hf_m=0.4 · dP_Pa=4000 · f=0.02 · L=10 · v=2 · D=0.1 · rho=1000 · g=10
`boundary-dw-f`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-dw-d`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-dw-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`property-dw-dp`	property	pass	4000 Pa
`property-dw-hf`	property	pass	Δp/(ρg)
`property-dw-identity`	property	pass	Δp=ρghf
`property-dw-zero`	property	pass	f=0
`property-dw-model`	property	pass	darcy_weisbach