Public evidence

physics.fluid.hydraulic_diameter

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 2 / 2
Boundary tests 8 / 8
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) @ 2026-09-17T06:27:56.932Z
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

Fingerprint sha256:7c0b6abb3feaef1d4ca77ef75fa3894e04cac58583096ad5793abb903ee8d253

Input schema sha256:0f4da45d859137348ae4dff97662c30d93b356e4bdd6d15d787a1c905890b09c · Output schema sha256:b9a5981e47461877ddac5c3cefe15429a50a835dbd1129ba4016a511616ede31 · 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: hydraulic-diameter
Engine: hydraulic-diameter
Engine build: 2026-09-17
Evidence core: 2026-09-17T04:08:59.124Z
Rendered: 2026-09-17T06:35:12.145Z
Last reviewed: —

Assumptions

D_h = 4 A / P_w; R = A / P_w = D_h / 4
Full circular pipe: D_h = D; closed rectangular duct: D_h = 2ab/(a+b); annulus: D_h = D_o − D_i
Not Q=Av, not Manning Q, not Reynolds, not Darcy, not a weir or orifice

Limitations

D_h = 4 A / P_w; R = A / P_w = D_h / 4
Full circular pipe: D_h = D; closed rectangular duct: D_h = 2ab/(a+b); annulus: D_h = D_o − D_i
Not Q=Av, not Manning Q, not Reynolds, not Darcy, not a weir or orifice

Sources

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

ISO 5167-1 — Measurement of fluid flow by means of pressure differential devices — Hydraulic diameter
Supports: D_h = 4A/P for non-circular conduits; annulus D_h = D_o − D_i
White, F.M. Fluid Mechanics — Noncircular ducts
Supports: Equivalent diameter D_h=4A/P; rectangular duct 2ab/(a+b)

Published checks

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

ID	Kind	Status	Detail
`golden-dh-section`	golden	pass	Expected Dh=0.1 · R=0.025 · A=0.01 · Pw=0.4 · mode=general · model=hydraulic_diameter · Actual mode=general · Dh=0.09999999999999999 · R=0.024999999999999998 · A=0.01 · Pw=0.4 · model=hydraulic_diameter
`golden-dh-circular`	golden	pass	Expected Dh=0.1 · D=0.1 · model=hydraulic_diameter · Actual mode=circular · Dh=0.1 · R=0.025 · A=0.007853981633974483 · Pw=0.3141592653589793 · model=hydraulic_diameter · D=0.1
`boundary-dh-rect`	boundary	pass	Expected Dh=0.13333333333333333 · a=0.2 · b=0.1 · model=hydraulic_diameter · Actual mode=rectangular · Dh=0.13333333333333333 · R=0.03333333333333333 · A=0.020000000000000004 · Pw=0.6000000000000001 · model=hydraulic_diameter · a=0.2 · b=0.1
`boundary-dh-annulus`	boundary	pass	Expected Dh=0.04 · model=hydraulic_diameter · Actual mode=annular · Dh=0.04000000000000001 · R=0.010000000000000002 · A=0.005026548245743671 · Pw=0.5026548245743669 · model=hydraulic_diameter · D_o=0.1 · D_i=0.06
`boundary-dh-from-r`	boundary	pass	Expected Dh=0.1 · R=0.025 · model=hydraulic_diameter · Actual mode=general · Dh=0.1 · R=0.025 · model=hydraulic_diameter
`boundary-dh-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`boundary-dh-a0`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-dh-mixed`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-dh-q`	boundary	pass	Expected MIXED_INPUT_ENCODING · Actual MIXED_INPUT_ENCODING
`boundary-dh-manning`	boundary	pass	Expected INVALID_MODE · Actual INVALID_MODE
`property-dh-4ap`	property	pass	4A/P=0.1
`property-dh-r`	property	pass	R=A/P
`property-dh-circ`	property	pass	D_h=D
`property-dh-rect`	property	pass	2ab/(a+b)
`property-dh-from-r`	property	pass	D_h=4R