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THE FEUTEX TOOLKIT

Choked Nozzle Mass Flow

Estimate ideal sonic mass flow and critical back-pressure ratio.

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01 Your input
02 Your result
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Formulamdot=Cd A*p0√(γ/(RT0))[2/(γ+1)]^((γ+1)/(2(γ−1))).
Sources and model references

Worked example

Inputs

Stagnation absolute pressure
200000 Pa
Stagnation temperature
300 K
Throat area
0.001 m²
Heat-capacity ratio
1.4
Specific gas constant
287 J/(kg·K)
Discharge coefficient
1

Expected results

Choked mass flow
0.4667117121 kg/s
Critical static to stagnation pressure ratio
0.5282817877

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter every input in the labeled units; use measured or independently specified properties.
  2. Check the stated model assumptions before calculating.
  3. Interpret the output as a model estimate and verify it independently for the intended application.

Try this example

{
  "pressure": 200000,
  "temperature": 300,
  "area": 0.001,
  "gamma": 1.4,
  "gas": 287,
  "cd": 1
}

Accuracy and scope

Requires back pressure low enough to choke the throat; constant-property ideal gas and adiabatic nozzle. Educational engineering estimate only; not structural or safety certification, equipment selection, or operating recommendations.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.