Blade pitch

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

Experimental investigation of effects of blade tip geometry on loads and performance for an articulated rotor system

Abstract: Wind-tunnel tests of an aeroelastically designed helicopter rotor model were carried out to determine the effects on dynamic response and aerodynamic performance of varying the design of the outboard 8 percent of the blade lengths. Four different blade tip geometries or shapes having different amounts of planform sweep, thickness and chordwise taper, and anhedral angle were studied. Each configuration was tested at several shaft angles of attack for advance ratios of 0.20, 0.30, 0.35, and 0.40. For each combination of shaft angle and advance ratio, rotor lift was varied over a wide range to include high lift conditions.

Vertical axis wind turbine using individual blade pitch and camber control integrated with matrix converter

Abstract: A vertical axis wind turbine that can be actively controlled is provided. This invention includes mechanisms and methods for enabling high-efficiency wind energy extraction by a vertical axis wind turbine using active pitch and camber control of individual blades. Blade control is further integrated with generator control and power electronics. Integrated control algorithms are systematically constructed, and transmitted to the wind turbine through a wireless communications interface. The interface also allows the user to continuously monitor the state of the wind turbine system. This invention includes sensors and procedures for periodic self-calibration of wind turbine parameters for preserving the long-term efficiency of wind energy extraction. Furthermore, a capability to intelligently interact with other wind turbine systems in a wind-farm setting is incorporated.

Ram-air turbines

Abstract: A ram-air turbine comprises a variable-pitch bladed rotor, a hydraulic actuator for effecting pitch variation of the blading of the rotor, and a pump driven by the rotor to supply fluid for operation of the actuator. A rotary speed-sensitive flyweight governor is provided to control the supply of fluid to the actuator whereby to cause the rotor automatically to rotate at constant speed, and the arrangement includes a machine driven by the rotor. The rotor, hydraulic actuator, pump, governor and driven machine are all coaxially arranged.

Electric pitch change device for a wind turbine

Abstract: The device uses electric motors (14) to adjust the rotor blade angle. The rotor blades (4) can be rotated in their feathered pitch by connection with a contactor (15) arranged in an emergency current circuit (7,12,14) with an independent energy source. At least one permanent magnet generator (7) assigned to the rotor shaft (2) is arranged in the emergency current circuit as the energy source. The electric motors are formed as short-circuit rotors, where the rotation field of the rotation current generated in the permanent magnet generator is connected to the short-circuit rotors, so that they rotate the rotor blades in their feathered pitch.

Electrical generator arrangement

Abstract: In some circumstances such as with regard to contra-rotating turbo prop arrangements in aircraft it is desirable to vary the pitch of the blades and/or provide de-icing facilities. Advantageously, these blade pitch and de-icing facilities could be provided through electrical actuators. Unfortunately, provision of electrical power to such rotating components traditionally requires utilisation of slip rings which are subject to wear. By providing a self-contained electrical generator comprising a first hub and second hub with respective generator parts it is possible to utilise the contra-rotating nature in order to create relative motion and therefore electrical power generation in coils opposed by permanent magnets. Slide contacts for electrical connection are avoided whilst electrical power can be generated within the rotating reference frame defined by the hubs.