Propeller Thrust & Efficiency Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/propeller/
Name: Date:
Learning objectives
- Explain how a propeller generates thrust.
- Relate thrust to the air it accelerates.
- Describe how blade pitch affects performance.
Variables to change
- Rotation speed (RPM)
- Blade pitch
- Airspeed
Procedure
- Spin the propeller and observe the thrust produced.
- Increase the RPM and observe thrust rise.
- Change the blade pitch and observe the effect on thrust and efficiency.
Observations
Record thrust versus RPM and blade pitch.
Questions
- How does a propeller produce thrust?
- How does thrust depend on rotation speed?
- What does blade pitch control?
- Why do many aircraft use variable-pitch propellers?
- What is propulsive efficiency?
Answer key (instructors)
- 1. By accelerating a mass of air rearward; the reaction pushes the aircraft forward.
- 2. It rises with RPM (more air accelerated per second), roughly with the square of speed at fixed pitch.
- 3. The angle of attack of the blades — how much air each blade grabs per revolution.
- 4. To stay efficient across takeoff, climb, and cruise, like gears on a bicycle.
- 5. The fraction of engine power converted into useful thrust power rather than wasted in the wake.
A propeller is a rotating wing that accelerates air backward, and the reaction thrusts the aircraft forward. Thrust rises with RPM and blade pitch; variable pitch keeps it efficient across flight phases, much like changing gears.