physics.fluid.gradual_contraction

Three distinct suites: educational examples on the calculator page, this legacy regression count (17/17 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-26.o2-o3. Calculation version 1.0.0. CVP 1.0.0-proposed. 4/4 golden · 9/9 CVP boundary · 10/10 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 5/5 CVP contract. digest 1f02ebf951d3. O2: conical confuser vs a separate-module identity (≤2 ULP). Not sudden contraction, not gradual expansion, not minor-loss K given, and not Q=Av. ≤2 ULP vs O3 applies only to the published tabulated gradual-contraction vectors. Not sudden contraction, not gradual expansion, not minor-loss K given, and not Q=Av.

• Golden (oracle-backed) 4 / 4
• CVP boundary 9 / 9
• Invalid input 10 / 10
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 2 / 2
• CVP contract 5 / 5
• Interfaces PASS · UI (SSR) / REST / MCP
• Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
• Verified scope h = K v2² / (2g) with K = 0.5 sin(α)(1 − v1/v2), plus pressure, velocity, and angle solves, + O3 mpmath tabulated head.
• Assurance Engineering
• Deferred Not sudden contraction, not gradual expansion, not minor-loss K given, and not Q=Av.

• release artifacts aligned PASS
• schema output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• rest success payload validates schema PASS

Fingerprint sha256:8c949a2cd78f6bdb29996178dab05dc8a10ba51f1e81fd21849416b8adaa04f9

Input schema sha256:0a98a436c7ed1874662c57bbc57d7b0c8b8ea185ac938829de8b6e4821ae7cf2 · Output schema sha256:be306b8b13ebad159fcb431f1d9ba3cdfacf9249ee684ec496d558e55a43da25 · 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

gradual-contraction

Engine

gradual-contraction

Engine build

2026-09-17

Evidence core

2026-09-17T11:28:31.444Z

Rendered

2026-11-10T05:18:41.955Z

Last reviewed

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Assumptions

• Conical contraction: h = K v2² / (2g); K = 0.5 sin(α) (1 − v1/v2); α wall half-angle; k and K reported, not inputs
• Require 0 < α < 90°; α=90° is sudden contraction; default g=9.80665 m/s²; default ρ=1000 kg/m³; incompressible; v2 > v1
• Not sudden contraction (C_c), not gradual expansion (v1−v2)², not minor-loss K given, not Darcy f, not orifice C_d, not Q=Av

Limitations

• Conical contraction: h = K v2² / (2g); K = 0.5 sin(α) (1 − v1/v2); α is wall half-angle; k and K are reported, not inputs
• Require 0 < α < 90°; α=90° is sudden contraction, not this page; default g=9.80665; default ρ=1000 for Δp; v2 > v1
• Not sudden contraction (C_c), not gradual expansion (v1−v2)², not minor-loss K given, not Darcy f, not orifice C_d, not Q=Av