Isentropic ratios
API · /isentropic-api
Isentropic Flow API
Isentropic compressible-flow (gas-dynamics) maths as an API, computed locally and deterministically. The isentropic endpoint gives the stagnation-to-static ratios of a perfect gas from a Mach number and the heat-capacity ratio γ (1.4 for air): the temperature ratio T0/T = 1 + (γ−1)/2·M², the pressure ratio p0/p = (T0/T)^(γ/(γ−1)), the density ratio and the area ratio A/A* relative to the sonic throat, and classifies the flow as subsonic, sonic or supersonic. The stagnation endpoint turns a static temperature and pressure plus a Mach number into the stagnation (total) conditions, the speed of sound a = √(γRT) and the flow velocity. The mach endpoint inverts the relations, solving the Mach number from a pressure, temperature or area ratio — an area ratio gives both the subsonic and supersonic roots — or from a velocity and temperature. Everything is computed locally and deterministically, so it is instant and private. Ideal for aerospace, propulsion, nozzle-design and wind-tunnel app developers, supersonic-flow and ducting tools, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is compressible isentropic flow; for the standard atmosphere use an atmosphere API and for incompressible Bernoulli flow a Bernoulli API.
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- 100.00%
- Server probes · 24h
- Avg latency
- 88 ms
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- 3,826
- active
- Total calls
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Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 2,000 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- Isentropic stagnation-to-static ratios
- Mach-number input, single gamma
- Deterministic JSON output
Starter
€9.00 /month
- 40,000 calls / month
- 5 requests / second
- Hard cap (429 above quota, no overage)
- Full pressure/temperature/density/area ratios
- Configurable specific-heat ratio gamma
- Mach-from-ratio inverse solving
- Email support
Pro
€24.00 /month
- 250,000 calls / month
- 20 requests / second
- Hard cap (429 above quota, no overage)
- Batch arrays of Mach numbers per call
- Subsonic and supercritical area-ratio branches
- Stagnation property sweeps for nozzle design
- Priority support
Mega
€74.00 /month
- 1,542,000 calls / month
- 60 requests / second
- Hard cap (429 above quota, no overage)
- High-throughput nozzle/CFD pre-processing volume
- Bulk Mach sweeps and tabulated flow curves
- Highest rate limit for design pipelines
- SLA-backed support
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Related APIs
Other APIs with overlapping tags.
Mach Number API
Mach-number and compressible-flow aerodynamics as an API, computed locally and deterministically. The mach endpoint computes the local speed of sound a = √(γ·R·T) (air γ = 1.4, R = 287.05 J/(kg·K)) and the Mach number M = v/a from a speed and a static temperature — given directly in °C or kelvin, or derived from a geopotential altitude through the International Standard Atmosphere (troposphere T = 288.15 − 0.0065·h up to 11 km, then the isothermal 216.65 K layer to 20 km) — and classifies the flight regime as subsonic, transonic, supersonic or hypersonic; the speed of sound is about 340.3 m/s at 15 °C and 295 m/s at 11 km. The speed endpoint inverts it, returning v = M·a in m/s, km/h and knots. The stagnation endpoint gives the isentropic total-to-static ratios T0/T = 1 + (γ−1)/2·M², P0/P = (T0/T)^(γ/(γ−1)) and ρ0/ρ = (T0/T)^(1/(γ−1)) — at Mach 2 the total pressure is about 7.82 times the static pressure — and will scale a supplied static temperature and pressure to their stagnation values. Everything is computed locally and deterministically, so it is instant and private. Ideal for aerospace, CFD, flight-simulation, wind-tunnel, UAV and aerodynamics-education app developers, compressible-flow and flight-envelope tools, and engineering software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is compressible aerodynamics; for viscous flow and the Reynolds number use a Reynolds API and for incompressible pressure/velocity a Bernoulli API.
api.oanor.com/machnumber-api
Rocket Equation API
Rocket-propulsion maths as an API, computed locally and deterministically. The delta-v endpoint applies the Tsiolkovsky rocket equation, Δv = ve·ln(m0/mf) with the exhaust velocity ve = Isp·g0, to give the velocity change a stage can produce from its wet (fuelled) mass, dry (burnout) mass and specific impulse — the delta-v budget that determines which manoeuvres are possible. The mass-ratio endpoint inverts the equation to give the mass ratio m0/mf = exp(Δv/ve) and the propellant mass fraction required to achieve a target delta-v, and, given a dry mass, the wet mass and propellant needed — revealing the steep, exponential tyranny of the rocket equation. The burn endpoint computes the propellant mass-flow rate ṁ = thrust/ve, the burn time and the total impulse from the thrust and propellant mass, and the delta-v if the wet mass is given. Masses are in kilograms, specific impulse in seconds, exhaust velocity and delta-v in metres per second and thrust in newtons, with standard gravity g0 = 9.80665 m/s². Everything is computed locally and deterministically, so it is instant and private. Ideal for aerospace, model-rocketry, spaceflight-simulation and orbital-mission app developers, stage-sizing and trajectory tools, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is rocket propulsion; for orbital velocity and escape velocity use an orbital-mechanics API.
api.oanor.com/rocket-api
SpaceX API
Latest, next and recent SpaceX launches with mission details, success status, mission patches, webcasts and articles, a single-launch lookup by id, and the full rocket fleet with specs, success rates and imagery. Great for space dashboards, trackers, education and hobby projects.
api.oanor.com/spacex-api
Reynolds Number API
Dimensionless flow-number maths for fluid-mechanics similitude as an API, computed locally and deterministically. The reynolds endpoint computes the Reynolds number, Re = v·L/ν = ρvL/μ — the ratio of inertial to viscous forces — from the velocity, a characteristic length (pipe diameter) and either the kinematic viscosity or the density and dynamic viscosity, and classifies the flow as laminar (< 2300), transitional (2300–4000) or turbulent (> 4000). The froude endpoint computes the Froude number, Fr = v/√(g·L) — the ratio of inertia to gravity used for open-channel and ship flows — together with the critical velocity, and tells you whether the flow is subcritical (tranquil), critical or supercritical (shooting). The mach endpoint computes the Mach number, M = v/c, with the sound speed taken directly or worked out from the air temperature, c = √(γRT), and classifies the speed as subsonic, transonic, supersonic or hypersonic. Everything is computed locally and deterministically, so it is instant and private. Ideal for fluid-mechanics, aerodynamics and hydraulics tools, model-scaling and wind-tunnel similitude, pipe-flow and open-channel analysis, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is dimensionless-number similitude; for pipe friction pressure drop use a Darcy-Weisbach API and for open-channel uniform flow use a Manning API.
api.oanor.com/reynolds-api
Frequently asked questions
Quick answers about pricing, quotas, and integration.
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Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/isentropic-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."
const res = await fetch("https://api.oanor.com/isentropic-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();
$ch = curl_init("https://api.oanor.com/isentropic-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);
import requests
r = requests.get(
"https://api.oanor.com/isentropic-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())
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