A variable-pitch propeller in aircraft design is a type of propeller where the angle of the blades can be adjusted by the pilot or automatically during flight. This feature allows the pilot to optimize the propeller’s performance for different phases of flight, such as takeoff, cruise, and landing, by changing the blade angle.
The formula to calculate the thrust generated by a variable-pitch propeller is more complex than that of a fixed-pitch propeller due to the variable nature of the blade angle. Here’s a simplified version of the formula:
- T is the thrust generated by the propeller (in newtons, N).
- π is the mathematical constant pi (approximately 3.14159).
- n is the rotational speed of the propeller (in revolutions per minute, RPM)
- r is the radius of the propeller (in meters, m)..
- p is the difference in air pressure between the front and back of the propeller (in pascals, Pa).
- η is the efficiency of the propeller (a dimensionless value between 0 and 1)