Home Developers Capabilities Manning formula

CVP verified calculation capability

Manning formula Calculation Capability

SI Manning open-channel discharge Q = (1/n) A R^{2/3} S^{1/2}. k=1. Not Q=Av, not Darcy–Weisbach, not a weir, not US customary 1.486.

Physics · Fluid Capability ID physics.fluid.manning version 1.0.0 CVP VERIFIED CURRENT Engineering

Model

Discharge

Modes: discharge · velocity · n · slope

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

SymbolQuantityUnitRole
nManning roughness n—input / output
AFlow area in m²—input / output
RHydraulic radius in m—input / output
PWetted perimeter in m—input
SFriction slope—input / output
QDischarge in m³/s—input / output
v——output
k——output
model——output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Not supported

Example

One numerical check. The calculator page holds worked steps and FAQ.

n=0.013 A=1 R=0.5 S=0.001 → Q=(1/n) A R^{2/3} S^{1/2}

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · SI Manning Q = (1/n) A R^{2/3} S^{1/2}, plus velocity, n, and S solves, + O3 mpmath tabulated discharge.. 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.

CVP
CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · SI Manning Q = (1/n) A R^{2/3} S^{1/2}, plus velocity, n, and S solves, + O3 mpmath tabulated discharge.· View Manifest · CVP overview · Specification
Verified scope
SI Manning Q = (1/n) A R^{2/3} S^{1/2}, plus velocity, n, and S solves, + O3 mpmath tabulated discharge.
Assurance
Engineering
Declared partition coverage
PASS · 5/5 declared partitions (discharge, solve, alias, awkward, invalid-domain)
Deferred
Not Darcy f, not Chezy C, not Hazen–Williams, not Q=Av, and not normal-depth yn.
Calculation version
1.0.0
Verification
13/13 calculation tests · 1/1 legacy golden · 7/7 legacy boundary · 5/5 legacy property
Production surface contract
5/5
Versions
Calculation 1.0.0 · CVP protocol 1.0.0-proposed · Evidence 2026-09-26.o2-o3
Verification revision
2026-09-26.o2-o3 · 1/1 property · digest 59bd904ca406
Reference
O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior
Numerical scope
O2: SI Manning vs a separate-module identity (≤2 ULP). Not Darcy f, not Chezy C, not Hazen–Williams, not Q=Av, and not normal-depth yn. ≤2 ULP vs O3 applies only to the published tabulated Manning vectors. Not Darcy f, not Chezy C, not Hazen–Williams, not Q=Av, and not normal-depth yn.
Interfaces
PASS · UI (SSR) / REST / MCP
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.
CVP suite
4/4 golden · 6/6 CVP boundary · 8/8 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 5/5 CVP contract
Supplemental domain review
Not performed
Named expert review
Not performed
Version lock
Supported (409 VERSION_MISMATCH)
Artifact consistency
Build verified · 1.0.0 (workspace artifacts agree)
Review-policy tier
Engine tested — catalog token engine_tested; supplemental; not CVP status
This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

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 5/5.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/manning-formula' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"n":0.013,"A":1,"R":0.5,"S":0.001},"calculation_version":"1.0.0"}'

POST /api/v1/calc/manning-formula. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id
manning-formula
Engine
manning-formula
REST
POST /api/v1/calc/manning-formula
MCP
execute_calculation with capability_id: "physics.fluid.manning"
Agent input schema
Canonical (MCP / Agent)
Output schema
JSON Schema (latest)
Versioned input schema
Immutable pin (1.0.0)
Versioned output schema
Immutable pin (1.0.0)

References

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

Try with an agent

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.manning"},"_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.