#venturi

Bernoulli and incompressible-flow maths as an API, computed locally and deterministically. The bernoulli endpoint applies Bernoulli's principle, P + ½ρv² + ρgh = constant along a streamline, taking the pressure, velocity and height at one point and solving the unknown pressure or velocity at a second point, and reporting the total head pressure. The dynamic-pressure endpoint computes the dynamic pressure q = ½ρv² from a velocity, or — the pitot-tube relation — the airspeed v = √(2q/ρ) from a measured dynamic pressure, plus the stagnation (total) pressure when a static pressure is supplied. The venturi endpoint computes the flow rate and inlet and throat velocities of a venturi or contraction from the inlet and throat areas and the pressure drop, Q = Cd·A₂·√(2ΔP/(ρ(1−(A₂/A₁)²))), combining continuity with Bernoulli, with an optional discharge coefficient. Density is taken from a value or a named fluid (air, water, seawater, oil). Everything is computed locally and deterministically, so it is instant and private. Ideal for aerospace, HVAC, plumbing, process and hydraulics app developers, airspeed and flow-meter tools, and fluid-mechanics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Bernoulli/streamline flow; for pipe friction head loss use a Darcy API and for orifice metering an orifice API.

api.oanor.com/bernoulli-api

Differential-pressure flow-meter maths (ISO 5167) as an API, computed locally and deterministically for orifice plates, venturi tubes and flow nozzles. The flow endpoint computes the mass and volumetric flow rate from the measured pressure drop across the meter, qm = Cd·ε·E·A·√(2·ρ·ΔP), where E = 1/√(1−β⁴) is the velocity-of-approach factor, β = d/D the diameter ratio and A the bore area — and it reports the throat velocity and the permanent (unrecovered) pressure loss. The pressure endpoint works the other way: from a known flow it returns the differential pressure the meter will develop, ΔP = (qm/(Cd·ε·E·A))²/(2ρ), and the permanent loss. The sizing endpoint solves the meter geometry: from a target flow and an allowable pressure drop it iterates the required bore diameter and diameter ratio, and flags whether β falls in the ISO-recommended 0.2–0.75 range. Each device type carries its standard discharge coefficient (orifice 0.61, venturi 0.984, nozzle 0.96) which you can override. Everything is computed locally and deterministically, so it is instant and private. Ideal for process, HVAC and instrumentation engineering tools, flow-meter selection and commissioning, and fluid-mechanics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is differential-pressure flow metering; for pipe continuity (Q=A·v) use a flow-rate API and for friction pressure drop use a Darcy-Weisbach API.

api.oanor.com/orifice-api