Measure thrust power, jet losses, and efficiency quickly. Switch methods, units, and export clean reports. Built for engineers evaluating propulsion systems across operating conditions.
| Case | Method | Flight Speed | Jet Speed | Mass Flow | Thrust | Input Power | Efficiency |
|---|---|---|---|---|---|---|---|
| Jet Cruise A | Ideal Jet Velocity | 180 m/s | 300 m/s | Optional | — | — | 75.00% |
| Nozzle Study B | Momentum | 150 m/s | 260 m/s | 24 kg/s | 2,790 N | — | 73.14% |
| Propeller Test C | Thrust Power | 70 m/s | — | — | 2,800 N | 250 kW | 78.40% |
ηp = 2V0 / (V0 + Ve)
Use this when forward speed and jet exit speed are known, and pressure thrust is negligible. It is a compact form derived from momentum thrust and kinetic energy rate.
T = ṁ(Ve − V0) + Tp
Puseful = T × V0
Pjet = 0.5ṁ(Ve2 − V02) + TpVe
ηp = Puseful / Pjet
Puseful = T × V0
ηp = (T × V0) / Pin
Where: V0 is flight speed, Ve is jet exit speed, ṁ is mass flow rate, Tp is pressure thrust, T is total thrust, and Pin is supplied or shaft power.
It measures how effectively input propulsion energy becomes useful thrust power. A higher value means more of the available power pushes the vehicle forward rather than leaving as excess jet kinetic energy.
Use the ideal jet method for quick aerodynamic studies, the momentum method when mass flow and pressure thrust are known, and the thrust power method for measured thrust and supplied power data.
For a conventional accelerating jet, exit velocity must exceed incoming flight velocity to produce positive momentum thrust. If it does not, the model may represent braking, measurement error, or an unsuitable method.
Yes. The thrust power method is especially useful for propellers and fans because it directly compares useful thrust power with measured shaft or supplied power.
Pressure thrust is the extra force caused by exhaust pressure not fully matching ambient pressure at the nozzle exit. It can materially affect thrust and efficiency in nozzle-based propulsion systems.
That usually indicates inconsistent data, unit mistakes, or a mismatch between thrust and power measurements. Recheck speeds, power entries, and whether the chosen method matches the available test data.
Yes. It converts supported speed, mass flow, thrust, and power inputs into base units internally before calculating the final efficiency and related engineering outputs.
It is excellent for rapid engineering estimates and comparison studies. Detailed engine design still needs fuller thermodynamic, aerodynamic, and installation analyses beyond these compact efficiency relations.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.