CVP verified calculation capability
Pipe head loss hf = f L v²/(2 g D) and Δp = ρ g hf from a given Darcy friction factor. Does not solve Colebrook for f.
Physics · Fluid Capability ID physics.fluid.darcy_weisbach version 1.0.0 CVP VERIFIED CURRENT Engineering
Head loss
hf = f L v² / (2 g D)Δp = ρ g hfCanonical symbols for this capability. Agent schemas remain the contract.
| Symbol | Quantity | Unit | Role |
|---|---|---|---|
f | Darcy friction factor | — | input / output |
L | Pipe length in metres | — | input / output |
v | Mean velocity in m/s | — | input / output |
D | Pipe inner diameter in metres | — | input / output |
rho | Fluid density in kg/m³ | — | input / output |
g | Gravity in m/s² | — | input / output |
hf | — | m | output |
dP | — | Pa | output |
model | — | — | output |
Declared scope for this capability. Do not use it outside this domain.
Assumptions
Not supported
One numerical check. The calculator page holds worked steps and FAQ.
f=0.02 L=10 v=2 D=0.1 rho=1000 → Δp=4000 Pa
CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · Darcy–Weisbach hf = f L v²/(2 g D) and Δp = ρ g hf from a given f, + O3 mpmath tabulated hf/Δp.. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.
Human page, REST, and MCP share the same engine and calculation_version.
Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json
and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 6/6.
curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/darcy-weisbach' \
-H 'Content-Type: application/json' \
-d '{"inputs":{"f":0.02,"L":10,"v":2,"D":0.1,"rho":1000},"calculation_version":"1.0.0"}'{
"inputs": {
"f": 0.02,
"L": 10,
"v": 2,
"D": 0.1,
"rho": 1000
},
"calculation_version": "1.0.0"
}POST /api/v1/calc/darcy-weisbach. This is a POST calculate endpoint — do not GET it.
Full REST contract: REST API docs.
Human-readable sources plus CVP reference evidence classes.
Sources
Reference evidence classes: O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior
Inspect, then execute. Same engine as REST and the human calculator.
curl -sS -X POST 'https://www.calculatorx.com/mcp' \
-H 'Content-Type: application/json' \
-H 'MCP-Protocol-Version: 2026-07-28' \
-H 'Mcp-Method: tools/call' \
-H 'Mcp-Name: inspect_capability' \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"physics.fluid.darcy_weisbach"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'curl -sS -X POST 'https://www.calculatorx.com/mcp' \
-H 'Content-Type: application/json' \
-H 'MCP-Protocol-Version: 2026-07-28' \
-H 'Mcp-Method: tools/call' \
-H 'Mcp-Name: execute_calculation' \
-d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_calculation","arguments":{"capability_id":"physics.fluid.darcy_weisbach","inputs":{"f":0.02,"L":10,"v":2,"D":0.1,"rho":1000},"calculation_version":"1.0.0"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'Pin calculation_version (1.0.0) when the result must stay reproducible.
Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.