Public evidence

physics.fluid.weir

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

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Verification

15/15 calculation tests · Production surface contract 3/3

Golden tests 1 / 1
Boundary tests 9 / 9
Property tests 5 / 5
Production surface contract 3 / 3
Engine tested Yes
Source checked Yes
Artifact integrity PASS
Production attestation Embedded snapshot: STALE · Last attested schema matched 1.0.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 163 CURRENT) @ 2026-09-17T03:09:03.307Z
Semantic contract PASS
Evidence attested at 2026-09-17T03:09:02.494Z
Last production check 2026-09-17T03:09:02.494Z
Public / cache PASS
Origin PASS
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

Fingerprint sha256:89f4b29e1866ab5aebf1de5dc2f8ea3977fde29a6c9c321d2824d2b28b459b96

Input schema sha256:2a4b8c2260cb328e0b5d7d09678ab65c431ca7e6f44cef407664bfeaad0fc564 · Output schema sha256:0fb770b1938aaa0ccc3fbc75ffcf04311171ef33a53871b941e2481fa2ac0a86 · 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: weir-discharge
Engine: weir-discharge
Engine build: 2026-09-17
Evidence core: 2026-09-17T01:37:27.321Z
Rendered: 2026-09-17T02:45:35.817Z
Last reviewed: —

Assumptions

Thin-plate weir; free nappe
SI g=9.80665 unless given
Rectangular: Q=(2/3) C_d L √(2g) H^{3/2}; not Francis contractions
Triangular: Q=(8/15) C_d √(2g) tan(θ/2) H^{5/2}
Not Manning, not Q=Av, not Darcy, not an orifice

Limitations

Thin-plate weir; free nappe; SI g=9.80665 unless given
Rectangular: Q=(2/3) C_d L √(2g) H^{3/2}; not Francis contractions
Triangular: Q=(8/15) C_d √(2g) tan(θ/2) H^{5/2}
Not Manning, not Q=Av, not Darcy, not an orifice

Sources

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

ISO 1438 — Hydrometry — Open channel flow measurement using thin-plate weirs — Rectangular and triangular thin-plate weirs
Supports: Thin-plate weir discharge from head over a sharp crest
ISO 80000-4 — Mechanics — Volume flow rate
Supports: Q is volume flow; H is a length (head)
Chow, V.T. Open-Channel Hydraulics — Sharp-crested weirs
Supports: Rectangular (2/3) C_d L √(2g) H^{3/2}; triangular (8/15) C_d √(2g) tan(θ/2) H^{5/2}

Published checks

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

ID	Kind	Status	Detail
`golden-weir-rect`	golden	pass	Expected Q=0.163727171653876 · H=0.2 · Cd=0.62 · L=1 · mode=rectangular · model=thin_plate_weir · Actual mode=rectangular · Q=0.163727171653876 · H=0.2 · Cd=0.62 · g=9.80665 · L=1 · model=thin_plate_weir
`boundary-weir-invert`	boundary	pass	Expected H=0.2 · model=thin_plate_weir · Actual mode=rectangular · Q=0.163727171653876 · H=0.20000000000000004 · Cd=0.62 · g=9.80665 · L=1 · model=thin_plate_weir
`boundary-weir-tri`	boundary	pass	Expected Q=0.024506260531418852 · Cd=0.58 · theta_deg=90 · mode=triangular · model=thin_plate_weir · Actual mode=triangular · Q=0.024506260531418852 · H=0.2 · Cd=0.58 · g=9.80665 · theta_deg=90 · model=thin_plate_weir
`boundary-weir-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`boundary-weir-h0`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-weir-mixed`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-weir-francis-cd`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-weir-francis`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`boundary-weir-orifice`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`boundary-weir-manning`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`property-weir-q`	property	pass	rect Q=(2/3)Cd L √(2g) H^{3/2}
`property-weir-h`	property	pass	H round-trip
`property-weir-tri`	property	pass	90° V-notch
`property-weir-cd`	property	pass	default Cd 0.62/0.58
`property-weir-model`	property	pass	thin_plate_weir