Verification
5/5 calculation tests · Production surface contract 1/1
- 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 STALE (1 capability; 163 remain CURRENT) @ 2026-09-17T23:16:16.380Z
- Semantic contract PASS
- Evidence attested at 2026-09-17T23:04:34.157Z
- Last production check 2026-09-17T23:04:34.157Z
- Public / cache PASS
- Origin PASS
- Supplemental domain review Not performed
- Named expert review Not performed
- release artifacts aligned PASS
Fingerprint sha256:a51b644431052e85cce3d588da7882736b24eda12a0e63d38647eb89ffc1d197
Input schema sha256:4de7933ae44ef93289fdd4a502783dd2a4e17dead2f8209d7f01dd2a36de2435 · Output schema sha256:658188bba055812aea650f2c22cc7fe94e8ab6189a8b1f07f1e1b952e4f4e79a · 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.
Engine identity and declared limitations.
- Tool
- concentric-reducer
- Engine
- concentric-reducer
- Engine build
- 2026-09-17
- Evidence core
- 2026-09-17T22:40:20.962Z
- Rendered
- 2026-09-17T23:36:55.416Z
- Last reviewed
- —
Assumptions
- Concentric reducer: h = K v₂² / (2g); K = 0.5 (1 − A₂/A₁); K referenced to downstream speed; K is reported, not an input
- A₂/A₁ in (0, 1); default g=9.80665 m/s²; default ρ=1000 kg/m³; incompressible; geometry from area_ratio or A1+A2 or D1+D2
- Not sudden expansion (v1−v2)², not gradual contraction α, not vena-contracta C_c, not catalog minor-loss K given, not a four-way cross, not Q=Av
Limitations
- Concentric reducer: h = K v₂² / (2g); K = 0.5 (1 − A₂/A₁); K referenced to downstream speed; K is reported, not an input
- A₂/A₁ in (0, 1); default g=9.80665; default ρ=1000 for Δp; incompressible; geometry from area_ratio or A1+A2 or D1+D2
- Not sudden expansion (v1−v2)², not gradual contraction α, not vena-contracta C_c, not catalog minor-loss K given, not a four-way cross, not Q=Av
Sources
Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.
- ISO 80000-4 — Mechanics — Length, speed, pressure
Supports: h is a head; v is a speed; Δp is a pressure
- Idelchik — Handbook of Hydraulic Resistance — Concentric reducer; K referenced to the downstream section
Supports: K=0.5(1−A₂/A₁) on v₂. Not vena-contracta C_c, not conical α, not catalog K
Published checks
Golden, boundary, and property cases included in this evidence build.
| ID | Kind | Status | Detail |
|---|
property-reducer-h | property | pass | h=K v₂²/(2g) |
property-reducer-K | property | pass | K=0.5(1−A₂/A₁) |
property-reducer-roundtrip-v | property | pass | v invert |
property-reducer-areas | property | pass | A1+A2 encoding |
property-reducer-model | property | pass | area_ratio_reducer |
