Self-regulating composite bearingless wind turbine

Cheney, Mari; Spierings, P.A.M.

doi:10.1016/0038-092x(78)90102-0

Cited by 9 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Approaches and objectives were quite varied. Cheney and Speirings (1978) regulated power with a centrifugally loaded mass on an elastic arm. Bottrell (1981) had a system for cyclically adjusting pitch for per rev load balancing.…”

Section: Wind Turbine Experiencementioning

confidence: 99%

The Use of Twist-Coupled Blades to Enhance the Performance of Horizontal Axis Wind Turbines

Lobitz¹,

Veers²,

Eisler³

et al. 2001

View full text Add to dashboard Cite

This paper reviews issues related to the use of aeroelastic tailoring as a cost-effective, passive means to shape the power curve and reduce loads. Wind turbine blades bend and twist during operation, effectively altering the angle of attack, which in turn affects loads and energy production. It is possible to build a small amount of desirable twisting into the load response of a blade with proper asymmetric fiber lay up in the blade skin. The tailored twisting can create an aeroelastic effect that has payoff in either better power production or in vibration alleviation, or both. Several research efforts have addressed different parts of this issue. Research and development in the use of aeroelastic tailoring on helicopter rotors is reviewed. Potential energy gains as a function of twist coupling are reviewed. The effects of such coupling on rotor stability have been studied and are presented. Fatigue damage estimates due to turbulent inflow have been computed for rotors employing several different control schemes, with and without twist-coupled blades. Energy output and maximum loads are also computed and compared 4

show abstract

Section: Wind Turbine Experiencementioning

confidence: 99%

The Use of Twist-Coupled Blades to Enhance the Performance of Horizontal Axis Wind Turbines

Lobitz¹,

Veers²,

Eisler³

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Multiple studies have proposed mechanisms to change the geometry of the whole blade in response to its instantaneous loading, either by allowing it to passively pitch around a given axis or by exploiting the elastic properties of composite materials. For instance, Cheney and Spierings (1978) proposed a mechanism where the blade is free to pitch around an axis along the span-wise direction, and it is connected to an eccentric mass; the moment generated by the centrifugal force acting on the mass around the pitching axis pitches the whole blade to feather when the rotor speed increases, thus reducing the loads generated and reducing the rotor angular velocity. Karaolis et al (1988) introduced the idea of biased composite lay-ups to achieve twist coupling in response to blade bending or centrifugal loads: with increasing wind speed the blade would pitch to stall, therefore regulating power generation.…”

mentioning

confidence: 99%

Model-scale experiments of passive pitch control for tidal turbines

Gambuzza¹,

Pisetta²,

Davey³

et al. 2022

Preprint

View full text Add to dashboard Cite

Tidal currents are renewable and predictable energy sources that could prove fundamental to decrease dependency from fossil fuels. Tidal currents, however, are highly unsteady and non uniform, resulting in undesirable load fluctuations on the blades and the drive train of turbines. A passive morphing blade concept capable to reduce the load fluctuations without affecting the mean loads has recently been formulated and demonstrated with numerical simulations (Pisetta et al., 2022). In this paper, we present the first demonstration of this morphing blade concept, through experimental tests on a 1.2-m diameter turbine. We show that fluctuations in the root-bending moment, thrust and torque are consistently reduced over a broad range of tip-speed ratios. This work also highlights some critical design aspects of morphing blades. For instance, it is showed that the friction resistance can substantially decrease the effectiveness of the system and thus must be minimised by design. Overall this paper demonstrates for the first time the effectiveness of morphing blades for tidal turbines, paving the way to the future development of this technology.

show abstract

Load Mitigation with Bending/Twist‐coupled Blades on Rotors using Modern Control Strategies

Lobitz

Veers

2002

Wind Energy

View full text Add to dashboard Cite

The prospect of installing blades that twist as they bend and/or extend on horizontal axis wind turbines provides opportunities for enhanced energy capture and/or load mitigation. Although this coupling could be achieved in either an active or a passive manner, the passive approach is much more attractive owing to its simplicity and economy. As an example, a blade design might employ coupling between bending and twisting, so that as the blade bends owing to the action of the aerodynamic loads, it also twists, modifying the aerodynamic performance in some way. For reducing loads the blades are designed to twist towards feather as they bend. For variable‐speed pitch‐controlled rotors, dynamic computer simulations with turbulent inflow show that twist coupling substantially decreases fatigue damage over all wind speeds, without reducing average power. Maximum loads also decrease modestly. For constant‐speed stall‐controlled and variable‐speed stall‐controlled rotors, significant decreases in fatigue damage are observed at the lower wind speeds and smaller decreases at the higher wind speeds. Maximum loads also decrease slightly. As a general observation, whenever a rotor is operating in the linear aerodynamic range (lower wind speeds for stall control and all wind speeds for pitch control), substantial reductions in fatigue damage are realized. Copyright © 2002 John Wiley & Sons, Ltd.

show abstract

Self-regulating composite bearingless wind turbine

Cited by 9 publications

References 0 publications

The Use of Twist-Coupled Blades to Enhance the Performance of Horizontal Axis Wind Turbines

The Use of Twist-Coupled Blades to Enhance the Performance of Horizontal Axis Wind Turbines

Model-scale experiments of passive pitch control for tidal turbines

Load Mitigation with Bending/Twist‐coupled Blades on Rotors using Modern Control Strategies

Contact Info

Product

Resources

About