Blade pitch

About: Blade pitch is a research topic. Over the lifetime, 5321 publications have been published within this topic receiving 63134 citations.

Wheel or rotor with a plurality of blades

Abstract: A wheel or rotor with a plurality of blades arranged at irregular or unequal pitch angles circumferentially of a disk, a hub or the like, wherein the characteristic level e k representative of the order-of-harmonic characteristic of blade pitch is defined by e.sub.k =10 log.sub.e d.sub.k +100 where ##EQU1## Z=a number of blades k=1,2, . . . and n; n≧Z θ j =the angular position of the tip or root of each blade defined in terms of a central angle subtended at the center of a circle, which is the axis of said wheel or rotor, by an arc extended from a reference point on said circle to said tip or root of each blade on said circle, j=1,2, . . . and Z; and the characteristic level e k satisfies the following conditions ##EQU2## where e=-13.14 log 10 Z+99.70 k=2,3, . . . n.

Retractable rotor blades for power generating wind and ocean current turbines and means for operating below set rotor torque limits

Abstract: A wind or water flow energy converter comprising a wind or water flow actuated rotor assembly. The rotor comprises a plurality of blades, wherein the blades of are variable in length to provide a variable diameter rotor. The rotor diameter is controlled to fully extend the rotor at low flow velocity and to retract the rotor as flow velocities increases such that the loads delivered by or exerted upon said rotor do not exceed set limits.

A morphing trailing edge device for a wind turbine

Abstract: The loads on wind turbine components are primarily from the blades. It is important to control these loads in order to avoid damaging the wind turbine. Rotor control technology is currently limited to controlling the rotor speed and the blade pitch. As blades increase in length, it becomes less desirable to pitch the entire blade as a single rigid body, but there is a requirement to control loads more precisely along the length of the blade. This can be achieved with aerodynamic control devices such as flaps. Morphing structures are good candidates for wind turbine flaps because they have the potential to create structures that have the conflicting abilities of being load carrying, lightweight and shape adaptive. A morphing flap design with an anisotropic cellular structure is presented, which is able to undergo large deflections and high strains. An aeroelastic analysis couples the work done by aerodynamic loads on the flap, the flap strain energy and the required actuation work to change shape. The morphing flap model is manufactured, and its stiffness is measured.

Power loss reduction in turbulent wind for a wind turbine using localized sensing and control

Abstract: A wind turbine blade assembly includes at least one local load sensor disposed on and/or within a surface of the wind turbine blade and at least one active flow modification device disposed on and/or within a surface of the wind turbine blade and configured to alter the aerodynamics of the wind turbine blade in response to real time local load sensor measurements such that a difference between a current angle of attack and an optimum angle of attack on the wind turbine blade is substantially minimized.