physics.fluid.critical_slope

• Golden tests 0 / 0
• Boundary tests 0 / 0
• Property tests 6 / 6
• Production surface contract 1 / 1
}
• 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; 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 PASS
• Origin PASS
• Supplemental domain review Not performed
• Named expert review Not performed

• release artifacts aligned PASS

Fingerprint sha256:c2f5651836299ba7386e67b77bddff3ca21c5413c57d7aa3e07c26466e2be2e4

Input schema sha256:bee92c1340983c10f27f9c26074189b5114bd975d4239a68133acbf4cd8a6e54 · Output schema sha256:36cce11023a310bc4ca0d3e3bba85cad8e58b9e240728139dd5d9e60000b873a · 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

critical-slope

Engine

critical-slope

Engine build

2026-09-18

Evidence core

2026-09-18T15:07:24.231Z

Rendered

2026-09-18T23:14:09.773Z

Last reviewed

—

Assumptions

• Rectangular yn=yc: Sc=[n Q/(A R^{2/3})]^2 at yc=(q²/g)^{1/3}; A=b yc; R=b yc/(b+2 yc); SI k=1; Sc is unknown in slope mode
• yc/b∈[0.2, 10]; n∈[0.008, 0.15]; Sc∈[1e-6, 0.1]; geometry is b, not A and R; default g=9.80665
• Not Manning Q with given A,R,S; not normal-depth yn invert; not critical-depth yc as the product; not Chezy C; not Q=Av; not trapezoid z

Limitations

• Rectangular critical slope: Sc such that yn=yc; SI Manning at y=yc; yc=(q²/g)^{1/3}; Sc=[n Q/(A R^{2/3})]^2 with A=b yc, R=b yc/(b+2 yc)
• yc/b∈[0.2, 10] so Sc(yc) is one-to-one; n∈[0.008, 0.15]; Sc∈[1e-6, 0.1]; SI k=1; default g=9.80665
• Not Manning Q from A,R,S; not normal-depth yn invert; not critical-depth yc as the product; not Chezy C; not Q=Av; not US k=1.486; not trapezoid z