physics.fluid.darcy_weisbach

Three distinct suites: educational examples on the calculator page, this legacy regression count (11/11 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 · 6/6 CVP boundary · 6/6 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract. digest 7ea3fe04b44a. O2: Darcy–Weisbach vs a separate-module identity (≤2 ULP). Not Colebrook f, not Manning, not Hazen–Williams, and not Q=Av. ≤2 ULP vs O3 applies only to the published tabulated Darcy–Weisbach vectors. Not Colebrook f, not Manning, not Hazen–Williams, and not Q=Av.

• Golden (oracle-backed) 4 / 4
• CVP boundary 6 / 6
• Invalid input 6 / 6
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 2 / 2
• CVP contract 6 / 6
• 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 Darcy–Weisbach hf = f L v²/(2 g D) and Δp = ρ g hf from a given f, + O3 mpmath tabulated hf/Δp.
• Assurance Engineering
• Deferred Not Colebrook f from Re/ε/D, not Manning, not Hazen–Williams, and not Q=Av.

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

Fingerprint sha256:655d4f1d3377c1b4af69e54ceeb465a0ba9e08330df9033b2d627bd8c40bf9df

Input schema sha256:87a5120e0303b9bef2ee820592411248e0e9ab8fcca99ecc1fd7b70c07a3939c · Output schema sha256:facaec23d012cbdcfe4ff878408123158e08e664d0f509ad52d2624349669601 · 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

darcy-weisbach

Engine

darcy-weisbach

Engine build

2026-09-16

Evidence core

2026-09-16T10:36:28.830Z

Rendered

2026-11-10T05:18:41.918Z

Last reviewed

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Assumptions

• Incompressible
• Constant Darcy friction factor
• Circular full-flow pipe
• g = 9.80665 m/s² unless given
• Does not solve Colebrook for f
• Not Hazen–Williams or minor-loss K

Limitations

• Incompressible; constant Darcy friction factor; circular pipe
• Does not solve Colebrook for f
• Not Hazen–Williams, not minor-loss K v²/2g
• Not volumetric flow Q=Av