What is meant by pitch angle in wind turbine?
Blade pitch or simply pitch refers to turning the angle of attack of the blades of a propeller or helicopter rotor into or out of the wind to control the production or absorption of power. Wind turbines use this to adjust the rotation speed and the generated power.
The addendum is the height by which a tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line; also, the radial distance between the pitch diameter and the outside diameter.
- Definition of pitch point. : the point of contact of the pitch lines of two gears or of a rack and pinion when in mesh.
- Backlash, a clearance between mating gear teeth, is built into speed reducers to let the gears mesh without binding and to provide space for a film of lubricating oil between the teeth. This prevents overheating and tooth damage.
- dedendum circle is the circle joining the roots of the gear teeths . so a small portion of tooth profile existbetween the two circle that is not involute. also we know that , interference is when the addendum circle of other mating gear interferes with the base circle or the non-conjugate profile of tooth .
Angle of attack (AOA) is the angle between the oncoming air or relative wind and a reference line on the airplane or wing. Pitch angle (attitude) is the angle between the longitudinal axis (where the airplane is pointed) and the horizon. This angle is dis- played on the attitude indicator or artificial horizon.
- In most airplanes, this is about 16 to 18 degrees. During cruise, the requirement is to maintain the angle of attack where the total drag on the airplane is minimum so as to use the minimum thrust and therefore, minimum fuel consumption. Typically, this occurs at an angle close to 8 degrees or so.
- Four Forces Affect Things That Fly:
- Weight is the force of gravity.
- Lift is the force that acts at a right angle to the direction of motion through the air.
- Thrust is the force that propels a flying machine in the direction of motion.
- Drag is the force that acts opposite to the direction of motion.
- In order to meet up at the trailing edge, the molecules going over the top of the wing must travel faster than the molecules moving under the wing. Because the upper flow is faster, then, from Bernoulli's equation, the pressure is lower. The difference in pressure across the airfoil produces the lift.
Updated: 2nd October 2019