physics.fluid.trapezoid_critical_depth

• Golden tests 0 / 0
• Boundary tests 0 / 0
• Property tests 5 / 5
• Production surface contract 1 / 1
}
• 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• Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-18T21:41:56.329Z
• Semantic contract PASS
• Evidence attested at 2026-09-18T21:41:55.460Z
• Last production check 2026-09-18T21:41:55.460Z
• Public / cache —
• Origin —
• Supplemental domain review Not performed
• Named expert review Not performed

• release artifacts aligned PASS

Fingerprint sha256:04b6b32a5369c4d4788307b54a2e0847df16ddd1bd3702ec8af5e6be11f6d59b

Input schema sha256:58e996e1feaef67c68521faa5e5cd2d87c403642356cdad1492611db45b3e669 · Output schema sha256:9ade55c11018764030d6a46206ad886218b0a973645928faf4a28da14fdd967c · 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.

Tool

trapezoidal-critical-depth

Engine

trapezoidal-critical-depth

Engine build

2026-09-18

Evidence core

2026-09-18T22:05:44.918Z

Rendered

2026-09-18T23:14:09.774Z

Last reviewed

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Assumptions

• Trapezoid critical depth: Fr=1 with A=(b+z yc) yc and T=b+2 z yc so Q² T = g A³; SI; default g=9.80665; z>0 is run/rise
• Critical speed vc = Q/A = √(g A/T) is reported, not an input; Fr=1 is the definition, not a Froude wrap
• Not rectangular yc=(q²/g)^{1/3}; not normal-depth yn; not specific energy E; not Manning n; not Q=Av

Limitations

• Trapezoid critical depth: Fr=1 with A=(b+z yc) yc and T=b+2 z yc so Q² T = g A³; SI; default g=9.80665; z>0 is run/rise
• Unknown is yc (depth mode) or Q (discharge invert); vc=√(g A/T) is reported; Fr=1 is the definition, not a Froude wrap
• Not rectangular yc=(q²/g)^{1/3}; not normal-depth yn; not specific energy E; not Manning n; not Q=Av