scholarly journals The Role of Active Flow-Control Devices in the Dynamic Aeroelastic Response of Wind Turbine Rotors

2017 ◽  
Author(s):  
Muraleekrishnan Menon Menon Muraleedharan Nair
2012 ◽  
Vol 134 (04) ◽  
pp. 51-51 ◽  
Author(s):  
G. Pechlivanoglou ◽  
C.N. Nayeri ◽  
C.O. Paschereit

This article describes the performance optimization of wind turbine rotors with active flow control. The active Gurney flap concept was tested in the wind tunnel under dynamic AoA variations to simulate unsteady inflow conditions. A high-deflection micro flap was actuated by four digital electric servos with a maximum deflection rate of 360°/sec. A custom code was created to allow dynamic AoA variations of the test wing with simultaneous dynamic force measurements. During the dynamic investigations, various control strategies were tested, starting from standard PID controllers with semi-empirical parameter tuning models to Direct Inverse Controllers with neural network tuning strategies and pure self-learning neural network controllers. The results of the closed-loop measurements using the manually tuned PID controller showed a reduction potential for the dynamic lift loads in the range of 70% as well as a stable controller behavior. The Direct Inverse Controller not only showed a load reduction of 36.8%, but also significant improvement potential with respect to its fine-tuning.


2012 ◽  
Vol 134 (08) ◽  
pp. 55-55 ◽  
Author(s):  
G. Pechlivanoglou ◽  
C.N. Nayeri ◽  
C.O. Paschereit

This article discusses the performance optimization of wind turbine rotors with active flow control. An extensive multi-parameter investigation with a thorough matrix-grading system was performed to identify the most suitable solution for industrial quality, short/mid-term implementation on actual utility scale wind turbines. A very wide selection of aerodynamic flow control solutions was analyzed based on extensive multi-disciplinary literature review and through aerodynamic and aeroelastic simulations. It is suggested that the trailing edge devices have the most favorable performance in the field of system integration and mechanical design performance. Compliant structures like the flexible flap keep the number of moving parts to a minimum while maintaining high performance and manufacturing simplicity. The use of flexible and elastic materials based on polymers or rubber material improves the lightning strike resistance of these solutions and allows for low-cost large-scale production. The actuator principle, sensitivity, and reliability are decisive parameters, and pneumatic actuators seem to strike a good balance between performance, cost, and reliability.


Author(s):  
G. Pechlivanoglou ◽  
C. N. Nayeri ◽  
C. O. Paschereit

This paper presents a series of investigations performed at the Hermann Fo¨ttinger Institute of TU Berlin. The initial scope of the investigations was the identification of Active Flow Control (AFC) solutions with significant implementation potential on wind turbine rotors. Several Active Flow Control solutions were thoroughly investigated based on extensive literature research. The performance of all the investigated solutions was ranked according to objective performance criteria and then the best performing solutions were selected for further numerical and experimental investigation. The selected Active Flow Control solutions were experimentally investigated with steady state wind tunnel measurements as well as steady state CFD simulations. The results of these investigations and the potential of each AFC solution are presented and discussed. The steady state tests were followed by a dynamic wind tunnel test campaign where the performance of one AFC solution (active Gurney flap) on a pitching test wing was investigated. The results of the static and dynamic investigations were very positive and proved the large load reduction potential of AFC on wind turbines.


2022 ◽  
Author(s):  
Sirko Bartholomay ◽  
Sascha Krumbein ◽  
Victoria Deichmann ◽  
Maik Gentsch ◽  
Sebastian Perez-Becker ◽  
...  

Author(s):  
Ahmed Aly ◽  
Jonathan Colton

Active flow control devices have been proven to reduce drag and delay stall on commercial aircraft. This leads to lower fuel usage and thus reduced flight costs. However, there is a large uncertainty as to how to integrate active flow control devices into aircraft, specifically those with composite structures. In addition, the cost of manufacturing active flow control devices for large-scale production has not been previously studied. In this article, design concepts for the attachment of a fluidic oscillator to a composite aircraft structure are investigated. A systematic approach from the conceptual design to the final design is performed using different design tools. A cost analysis is performed to select the most cost-effective design configuration based on large volume fluidic oscillator production. Through design validation and cost estimation, the final design is shown to be feasible for large volume manufacturing.


2022 ◽  
Author(s):  
Abderahmane Marouf ◽  
Dinh Hung Truong ◽  
Yannick Hoarau ◽  
Alain Gehri ◽  
Dominique Charbonnier ◽  
...  

Author(s):  
Mohd S. Aris ◽  
Ieuan Owen ◽  
Chris J. Sutcliffe

This paper is concerned with the convective heat transfer of heated surfaces through the use of active flow control devices. An investigation has been carried out into the use of two flow control design configurations manufactured from Shape Memory Alloys (SMAs) which are activated at specified temperatures. In this design, a high surface temperature would activate rectangular flaps to change shape and protrude at a 45° angle of attack. This protrusion would generate longitudinal vortices and at the same time allow air to flow into cooling channels underneath the flaps, cooling a heated surface downstream of the flow control device. One- and two-channel flow control configurations were explored in this work. The flow control device was made from pre-alloyed powders of SMA material in a rapid prototyping process known as Selective Laser Melting (SLM). It was tested for its heat transfer enhancement in an open test section wind tunnel supplied with low velocity air flow. Infrared thermography was used to evaluate the surface temperatures of the downstream heated surface. Promising results were obtained for the flow control design when the heated surface temperatures were varied from 20 °C to 85 °C. In the one-channel configuration, the flow control device in its activated shape increased heat transfer to a maximum of 50% compared to its deactivated shape. The activated flow control device in the two-channel configuration experienced a heat transfer enhancement of up to 90% compared to when it is deactivated.


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