Public evidence

physics.fluid.venturi

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

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Verification

17/17 calculation tests · Production surface contract 4/4

Golden tests 2 / 2
Boundary tests 10 / 10
Property tests 5 / 5
Production surface contract 4 / 4
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) @ 2026-09-17T06:27:56.932Z
Semantic contract PASS
Evidence attested at 2026-09-17T06:27:56.176Z
Last production check 2026-09-17T06:27:56.176Z
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
schema rejects incomplete input PASS

Fingerprint sha256:a8883abb131362b9a281b5c4790a515f8c17b6890ef76f0040c477af31316db2

Input schema sha256:c4da2ae37ad4ee5e90b9bbaf74312fe153c1c329d3f98a66377ac11f4d52e539 · Output schema sha256:6026cf5a2c5ebcdb14abe4f7f002bc1233ea273c3230da7855d0ad4bd663665c · 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: venturi
Engine: venturi
Engine build: 2026-09-17
Evidence core: 2026-09-17T05:19:25.805Z
Rendered: 2026-09-17T06:35:12.147Z
Last reviewed: —

Assumptions

Incompressible venturi tube; SI; default C_d=0.98; C_d in (0, 1]
Q=C_d A2 √(2Δp/(ρ(1−β⁴))), β=D2/D1; Q_ideal uses C_d=1
Optional same-fluid manometer Δh with Δp=ρ g Δh; not tank H
Not an orifice plate, not Q=Av, not Darcy, not minor-loss K, not valve Cv/Kv

Limitations

Incompressible venturi: Q = C_d A2 √(2Δp/(ρ(1−β⁴))), β=D2/D1; default C_d=0.98
Ideal Bernoulli Q_ideal uses C_d=1; optional same-fluid manometer Δh, Δp=ρ g Δh
Not an orifice plate, not Q=Av, not Darcy, not minor-loss K, not valve Cv/Kv

Sources

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

ISO 5167-4 — Measurement of fluid flow by means of pressure differential devices — Venturi tubes — Incompressible discharge with velocity-of-approach factor
Supports: Q = C E (π/4) D2² √(2Δp/ρ); E = 1/√(1−β⁴); this page takes C as an input with default 0.98
White, F.M. Fluid Mechanics — Venturi meter from Bernoulli plus continuity
Supports: Ideal Q = A2 √(2Δp/(ρ(1−β⁴))); a discharge coefficient C_d < 1 accounts for losses

Published checks

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

ID	Kind	Status	Detail
`golden-vt-q`	golden	pass	Expected Q=0.008887616884747668 · Cd=0.98 · mode=flow · model=venturi · Actual mode=flow · Q=0.008887616884747668 · Q_ideal=0.00906899682117109 · D1=0.1 · D2=0.05 · beta=0.5 · E=1.0327955589886444 · A1=0.007853981633974483
`golden-vt-dh`	golden	pass	Expected Q=0.008887616884747668 · dP=10000 · model=venturi · Actual mode=flow · Q=0.008887616884747668 · Q_ideal=0.00906899682117109 · D1=0.1 · D2=0.05 · beta=0.5 · E=1.0327955589886444 · A1=0.007853981633974483
`boundary-vt-dp`	boundary	pass	Expected dP=10000 · model=venturi · Actual mode=pressure · Q=0.008887616884747668 · Q_ideal=0.00906899682117109 · D1=0.1 · D2=0.05 · beta=0.5 · E=1.0327955589886444 · A1=0.007853981633974483
`boundary-vt-d2`	boundary	pass	Expected D2=0.05 · model=venturi · Actual mode=throat · Q=0.008887616884747668 · Q_ideal=0.00906899682117109 · D1=0.1 · D2=0.05 · beta=0.5 · E=1.0327955589886444 · A1=0.007853981633974483
`boundary-vt-cd`	boundary	pass	Expected Cd=0.98 · model=venturi · Actual mode=Cd · Q=0.008887616884747668 · Q_ideal=0.009068996821171089 · D1=0.1 · D2=0.05 · beta=0.5 · E=1.0327955589886444 · A1=0.007853981633974483
`boundary-vt-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`boundary-vt-d2ge`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-vt-orifice-d`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-vt-cv`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-vt-qav`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-vt-orifice-mode`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`boundary-vt-tank-h`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`property-vt-q`	property	pass	Cd E A2 √(2Δp/ρ)
`property-vt-ideal`	property	pass	Q=Cd Q_ideal
`property-vt-roundtrip-dp`	property	pass	Δp invert
`property-vt-dh`	property	pass	Δh encoding
`property-vt-model`	property	pass	venturi