Compressible Nozzle Flow

Rocket engines squeeze gas through a converging–diverging nozzle to reach supersonic speeds. Watch flow choke at the throat and go supersonic downstream.

Compressible Nozzle FlowLive

converging–diverging & choked flow

Controls

Presets

Specific-heat ratio γ

Back/stagnation pressure ratio

In a converging–diverging (de Laval) nozzle, gas accelerates to Mach 1 at the throat, then goes supersonic in the diverging section. The exit Mach number follows from the pressure ratio via isentropic flow relations. Educational tool.

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Data Inspector

Exit Mach number1.71

Area ratio Aₑ/A*1.35

Flow regimesupersonic

Governing equation

\frac{A _{e}}{A ^{*}} = \frac{1}{1.71} [\frac{2}{1.4 + 1} (1 + \frac{1.4 - 1}{2} 1.7 1^{2})]^{\frac{1.4 + 1}{2 ( 1.4 - 1 )}} = 1.35

Reading this result: Exit Mach 1.71 is supersonic — the flow chokes at Mach 1 in the throat, then the diverging section keeps accelerating it, which demands an area ratio Ae/A* of 1.35.

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How it works

In a de Laval nozzle, gas accelerates in the converging section to exactly Mach 1 at the throat (choked), then continues accelerating supersonically in the diverging section. The exit Mach number follows from the stagnation-to-back pressure ratio via isentropic relations. Educational tool.

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Frequently asked questions

Is this de laval nozzle simulator tool really free?▾

Yes. Compressible Nozzle Flow runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

Do I need to install anything?▾

No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.

Can I save or share my simulation?▾

Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.

How accurate are the results?▾

The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.