Verified calculation capability

ISO 5167 Venturi tube Calculation Capability

ISO 5167-4 classical Venturi tube Q=C E A2 √(2Δp/ρ) with C from convergent type. Not given C_d=0.98, not ISA 1932, not RHG orifice, not Q=Av, not Darcy. · Physics · Fluid

Capability ID physics.fluid.iso_venturi · version 1.0.0

Open calculator REST API MCP Evidence Evidence JSON Review policy

Model

Discharge

Discharge: Q = C E A2 √(2Δp / ρ)
Approach: β = D2/D1 · E = 1/√(1 − β⁴)
Machined C: C = 0.995 (ISO 5167-4 machined convergent)

Solve modes: flow · pressure · coefficient

Inputs / Outputs

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

Symbol	Quantity	Unit	Role
`D1`	Inlet diameter in m. Required. Envelope depends on kind. Alternative: D_inlet. Do not send orifice D+d.	—	input / output
`D2`	Throat diameter in m. Required unless beta. Alternative: D_throat. Do not mix with beta.	—	input / output
`beta`	D2/D1. Alternative to D2. Alternative: diameter_ratio. Envelope depends on kind.	—	input / output
`Re_D`	Pipe Reynolds number on D1. Required. Envelope depends on kind. Alternatives: Re, ReD. Do not send ρ, μ, v.	—	input / output
`kind`	machined (default, C=0.995), rough (C=0.985), or as_cast (C=0.984). Alternative: convergent.	—	input / output
`dP`	Inlet-to-throat differential pressure in Pa. Required for flow. Alternatives: deltaP, dP_Pa, dp.	—	input / output
`rho`	Density in kg/m³. Required for flow and pressure.	—	input / output
`Q`	Volume flow in m³/s. Required for pressure invert. Alternative: flow, Q_m3_s.	—	input / output
`E`	—	—	output
`A1`	—	—	output
`A2`	—	—	output
`C`	—	—	output
`Cd`	—	—	output
`v1`	—	—	output
`v2`	—	—	output
`model`	—	—	output

Assumptions / Validity

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

Assumptions

ISO 5167-4 classical Venturi tube: Q = C E A2 √(2Δp/ρ); C from convergent type; β and Re_D bound the ISO envelope; incompressible ε=1; C is reported, not an input
Machined C=0.995, D∈[50 mm,250 mm], β∈[0.40,0.75], Re_D∈[2e5,1e6]. Rough-welded C=0.985. As-cast C=0.984
Not a given C_d=0.98, not ISA 1932 nozzle, not RHG orifice, not Q=Av, not Darcy f, not compressible ε

Not supported

given C_d=0.98
ISA 1932 nozzle
RHG orifice
Q=Av
Darcy f
compressible ε

Example

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

D1=0.1 D2=0.05 Re_D=5e5 dP=10000 rho=1000 machined → C=0.995 Q≈0.009024

Open this example in the calculator

Trust

Review-policy: engine tested — automated tests, sources, version lock, and evidence published. Supplemental to CVP; not Domain Expert Review. See CVP and Review policy.

Tier: Engine tested — catalog token engine_tested
Calculation version: 1.0.0
Evidence tests: 5/5 calculation tests · golden 0/0 · boundary 0/0 · property 5/5
Engine tested: Yes
Source checked: Yes
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)

Production attestation: Embedded snapshot: STALE · Last attested schema matched 1.0.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-18T02:44:05.986Z
Semantic contract: PASS
Evidence attested at: 2026-09-18T02:44:05.231Z
Last production check: 2026-09-18T02:44:05.231Z
Public / cache: PASS
Origin: PASS

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. Production surface contract 1/1.

Tool id: iso-venturi
Engine: iso-venturi
REST: POST /api/v1/calc/iso-venturi
MCP: execute_calculation with capability_id: "physics.fluid.iso_venturi"
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

Try with an agent

Inspect this capability via same-origin MCP, then call execute_calculation.

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.iso_venturi"}}}'

Inspect the trust tier and required assurance level before execution. Pin calculation_version (1.0.0) when reproducibility matters. Full protocol notes: MCP docs.