Jet Engine Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/jet/
Name: Date:
Learning objectives
- Explain how a jet engine produces thrust.
- Name the stages of the Brayton cycle.
- Relate thrust to airflow and exhaust speed.
Variables to change
- Airflow rate
- Compression ratio
- Fuel flow
Procedure
- Run the engine and follow air through intake, compressor, combustor, turbine, and nozzle.
- Increase fuel flow and observe thrust and exhaust speed.
- Change the airflow and observe the effect on thrust.
Observations
Record thrust versus fuel and airflow, and note where air is compressed, heated, and expanded.
Questions
- How does a jet engine create thrust?
- Name the Brayton-cycle stages.
- Write thrust in terms of airflow and speed.
- What does the turbine do?
- Why do high-bypass turbofans improve efficiency?
Answer key (instructors)
- 1. By accelerating a mass of air rearward; the reaction force pushes the engine forward (Newton’s third law).
- 2. Intake, compression, combustion (heat addition), expansion through the turbine, and exhaust.
- 3. Thrust ≈ ṁ·(v_exhaust − v_inlet) — mass flow times the increase in speed.
- 4. Extracts energy from the hot gas to drive the compressor.
- 5. They move more air at lower speed, which is more efficient for subsonic flight.
A jet engine follows the Brayton cycle: it compresses incoming air, burns fuel to heat it, and expands it through a turbine and nozzle. Thrust ≈ ṁ·(v_exhaust − v_inlet) — accelerating air backward pushes the engine forward.