Optimal Wind Turbine Operation by Artificial Neural Network-Based Active Gurney Flap Flow Control

Abstract

Flow control devices have been introduced in the wind energy sector to improve the aerodynamic behavior of the wind turbine blades (WTBs). Among these flow control devices, Gurney flaps (GFs) have been the focus of innovative research, due to their good characteristics which enhance the lift force that causes the rotation of the wind turbine rotor. The lift force increment introduced by GFs depends on the physical characteristics of the device and the angle of attack (AoA) of the incoming wind. Hence, despite a careful and detailed design, the real performance of the GFs is conditioned by an external factor, the wind. In this paper, an active operation of GFs is proposed in order to optimize their performance. The objective of the active Gurney flap (AGF) flow control technique is to enhance the aerodynamic adaption capability of the wind turbine and, thus, achieve an optimal operation in response to fast variations in the incoming wind. In order to facilitate the management of the information used by the AGF strategy, the aerodynamic data calculated by computational fluid dynamics (CFD) are stored in an artificial neural network (ANN). Blade element momentum (BEM) based calculations have been performed to analyze the aerodynamic behavior of the WTBs with the proposed AGF strategy and calculate the corresponding operation of the wind turbine. Real wind speed values from a meteorological station in Salt Lake City, Utah, USA, have been used for the steady BEM calculations. The obtained results show a considerable improvement in the performance of the wind turbine, in the form of an enhanced generated energy output value and a reduced bending moment at the root of the WTB.

Performance enhancement of the artificial neural network–based reinforcement learning for wind turbine yaw control

“…The use of real wind speed data in the FAST simulation environment is important since it allows a detailed analysis of the performance of the designed control strategy in a realistic scenario. In fact, the data collected from this meteorological station have been used in several publications …”

“…In fact, the data collected from this meteorological station have been used in several publications. 40,41 A detailed analysis of the available wind data has been conducted, and six different cases with a variety of stable wind conditions have been identified and isolated to be used in the study of the performance of the proposed yaw control system. One example case where the wind conditions remain rather stable during a time span of 10 000 s is represented in Figure 11.…”

Active Control of Bluff-Body Flows Using Plasma Actuators

“…that modify the exterior geometry of the body as a function of time. For instance, piezoelectric bending actuators have been used to drive flaps to manipulate the flow at the back of a nominally two-dimensional blunt trailing edge [52] and active Gurney flaps have been used to control the aerodynamic characteristics of wind turbine blades [53]. In these examples, dynamic shape modification is enabled via servo-mechanisms or microelectromechanical systems to actively control the exterior flow.…”

Numerical Analysis on the Effectiveness of Gurney Flaps as Power Augmentation Devices for Airfoils Subject to a Continuous Variation of the Angle of Attack by Use of Full and Surrogate Models

“…After conducting few tests, he found out that this simple modification allowed approaching turns with higher velocity and also increasing the car speed on straight lines. The simple construction of this device has encouraged researchers to investigate its application in different areas [7][8][9][10], and especially in wind turbines, where they do represent one of the most interesting solutions [11,12]. It has been found that the effect of the lift coefficient enhancement of the GF is connected with the change of the flow structure at the trailing edge, as it is shown in Figure 1, which reports the vorticity contours near the trailing edge of the airfoil.…”