physics.fluid.parshall_flume

• 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: 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) @ 2026-09-18T02:44:05.986Z
• Semantic contract PASS
• Evidence attested at 2026-09-18T02:44:05.231Z
• Last production check 2026-09-18T02:44:05.231Z
• Public / cache PASS
• Origin PASS
• Supplemental domain review Not performed
• Named expert review Not performed

• release artifacts aligned PASS

Fingerprint sha256:1981ec4a2f54540c0accb1f971c4b9c0bcbb3fd809e0b682dade8a8addf403cc

Input schema sha256:a828b1179d383ead18e23c10c17e5fb871c2d097d4e8686c12785b172209715f · Output schema sha256:f4a4778a5b961065b23de5d1bcb61a5be0e687b6156a0118297bb69599ffc475 · 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

parshall-flume

Engine

parshall-flume

Engine build

2026-09-18

Evidence core

2026-09-18T02:23:57.439Z

Rendered

2026-09-18T03:31:40.489Z

Last reviewed

—

Assumptions

• USBR 1–8 ft Parshall free flow: Q_cfs = 4 W_ft Ha_ft^n, n=1.522 W_ft^{0.026}; SI W, Ha, Q; n is reported, not an input
• Ha is the specified-gage upstream head, not weir crest head H; W∈[0.3048 m, 2.4384 m]; Ha∈[0.03048 m, 1.6764 m]; free nappe only
• Not thin-plate (2/3) C_d L √(2g) H^{3/2}, not broad-crested (2/3)^{3/2} b √g H^{3/2}, not Manning n, not Q=Av, not orifice, not submerged Hb

Limitations

• USBR 1–8 ft Parshall free flow: Q_cfs = 4 W_ft Ha_ft^n, n=1.522 W_ft^{0.026}; SI W, Ha, Q; n is reported, not an input
• Ha is the specified-gage upstream head, not weir crest head H; W∈[0.3048 m, 2.4384 m]; Ha∈[0.03048 m, 1.6764 m]; free nappe only
• Not thin-plate (2/3) C_d L √(2g) H^{3/2}, not broad-crested (2/3)^{3/2} b √g H^{3/2}, not Manning n, not Q=Av, not orifice, not submerged Hb