Blade pitch

Pitch ( German: slope, incline, inclination angle) referred to in applications of aerodynamics, particularly in the aviation industry as well as in wind turbines propeller pitch or rotor:

• For propeller airplanes, the pitch of the rotor blades is adjusted to achieve the best efficiency of the drive depending on the flight speed - see the propeller.
• For helicopters, the pitch lever controls the collective pitch of the rotor blades and thus the vertical acceleration, so the rise and fall of the aircraft. The mechanical conversion is usually done by a vertical displacement of the swash plate on the main rotor shaft. In electrically driven vertical takeoff, approximately in the model, the term is often also used for the corresponding direction control when it is implemented only by changes in rotational speed of the ( electric ) motor.

• In modern wind turbines the pitch of the rotor blades is automatically adjusted to regulate the output of the system and achieve an optimal efficiency of each unit at varying wind speeds. While above the rated speed, the pitch is changed gradually in order to limit the power consumption and the burden on the facility and to prevent passage of the rotor. The permanent readjustment of pitchs the system can be run continuously at their rated power thus in the speed range between about 12 and 25 m / s. At very high wind speeds the rotor blades (typically 25-33 m / s) to be filmed entirely in the feathered position, whereby the lift stops and the system therefore automatically turns off. In this way, damage can be avoided by gale-force winds.

Furthermore, the English pitch and the movement about the transverse axis denotes in aircraft control ( German: nod ) and the inclination angle to the horizontal, see roll- pitch-yaw angle.