physics.fluid.npsh

Three distinct suites: educational examples on the calculator page, this legacy regression count (14/14 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 · 7/7 CVP boundary · 9/9 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract. digest 6800deb08ffc. O2: NPSHa vs a separate-module identity (≤2 ULP). Not pump power, not orifice C_d, not Darcy f, and not Manning n. ≤2 ULP vs O3 applies only to the published tabulated NPSH vectors. Not pump power, not orifice C_d, not Darcy f, and not Manning n.

• Golden (oracle-backed) 4 / 4
• CVP boundary 7 / 7
• Invalid input 9 / 9
• 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 Open-tank and flange NPSHa, optional margin vs NPSHr, + O3 mpmath tabulated NPSHa.
• Assurance Engineering
• Deferred Not pump power, not orifice C_d, not Darcy f, and not Manning n.

• 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:d5b3082a766fb3f71a877c6f768057b8b8d12c7a39d98164672515b31dadfe70

Input schema sha256:4d99adcedf50829825531778ad1444c70c70aea4e5079b77a91f01e7814a4e34 · Output schema sha256:38d11ab23ad0d1d705d2d3d584e0fa3b4a702f6486b4eaa3ae638c46b13a9a24 · 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

npsh

Engine

npsh

Engine build

2026-09-17

Evidence core

2026-09-17T03:58:19.307Z

Rendered

2026-11-10T05:18:41.923Z

Last reviewed

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Assumptions

• NPSHa = (p_s − p_v)/(ρ g) + v_s²/(2g) + z_s; pressures absolute; SI
• Open tank: p_s=p_atm (default 101325 Pa), z_s=z−hf, v_s=0; hf is an input
• Not pump power, not orifice, not weir, not Q=Av, not Darcy, not a catalog NPSHr curve, not steam p_v(T)

Limitations

• NPSHa = (p_s − p_v)/(ρ g) + v_s²/(2g) + z_s; pressures absolute; SI
• Open tank: p_s=p_atm (default 101325 Pa), z_s=z−hf, v_s=0; hf is an input
• Not pump power, not orifice, not weir, not Q=Av, not Darcy, not a catalog NPSHr curve, not steam p_v(T)