scholarly journals Comparison of a Response Surface Method and Artificial Neural Network in Predicting the Aerodynamic Performance of a Wind Turbine Airfoil and Its Optimization

2020 ◽  
Vol 10 (18) ◽  
pp. 6277 ◽  
Author(s):  
Sahuck Oh
Keyword(s):  
Wind Turbine ◽  
Performance Improvement ◽  
Surrogate Model ◽  
Prediction Accuracy ◽  
High Performance ◽  
Aerodynamic Performance ◽  
Surrogate Models ◽  
Surface Method ◽  
Wind Turbine Airfoil ◽  
High Level

To find the optimal design for an engineering object, thousands of (or even more) simulations should be implemented to obtain the outcome data for the variously designed objects. However, repeating simulations this many times is impossible because a typical simulation is a computationally expensive task. Instead of conducting all the required simulations, a more efficient way is predicting the outcome from the approximation model, called the surrogate model. The response surface method (RSM) with polynomials and artificial neural network (ANN) are the most prominent methods in constructing a surrogate model in the engineering fields. In this study, the prediction accuracy of the surrogate models computed by using an RSM and ANN is compared with several datasets showing different complexities. This comparison is investigated by constructing the surrogate models in predicting aerodynamic performance of a wind turbine airfoil. In the current paper, it is verified that the prediction accuracy of the ANN-computed surrogate model is higher than the RSM-computed one when the datasets have a high level of complexity, but the opposite phenomenon is observed if the datasets have a low level of complexity. When the surrogate models with different accuracies are used to enhance the performance of a wind turbine airfoil, the surrogate model with a high level of accuracy produces the optimal design, showing a high performance improvement. The current study is expected to give guidance on how to properly choose between an RSM and ANN to construct a highly accurate surrogate model that can help in finding a design with a high performance improvement during the optimization process.

Aerodynamic Analysis of an Airfoil With Leading Edge Pitting Erosion

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Yan Wang ◽  
Ruifeng Hu ◽  
Xiaojing Zheng
Keyword(s):  
Wind Turbine ◽  
Indirect Effects ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Distribution Area ◽  
Navier Stokes Equation ◽  
Turbine Performance ◽  
Wind Turbine Airfoil ◽  
Cfd Method

Leading edge erosion is a considerable threat to wind turbine performance and blade maintenance, and it is very imperative to accurately predict the influence of various degrees of erosion on wind turbine performance. In the present study, an attempt to investigate the effects of leading edge erosion on the aerodynamics of wind turbine airfoil is undertaken by using computational fluid dynamics (CFD) method. A new pitting erosion model is proposed and semicircle cavities were used to represent the erosion pits in the simulation. Two-dimensional incompressible Reynolds-averaged Navier–Stokes equation and shear stress transport (SST) k–ω turbulence model are adopted to compute the aerodynamics of a S809 airfoil with leading edge pitting erosions, where the influences of pits depth, densities, distribution area, and locations are considered. The results indicate that pitting erosion has remarkably undesirable influences on the aerodynamic performance of the airfoil, and the critical pits depth, density, and distribution area degrade the airfoil aerodynamic performance mostly were obtained. In addition, the dominant parameters are determined by the correlation coefficient path analysis method, results showed that all parameters have non-negligible effects on the aerodynamics of S809 airfoil, and the Reynolds number is of the most important, followed by pits density, pits depth, and pits distribution area. Meanwhile, the direct and indirect effects of these factors are analyzed, and it is found that the indirect effects are very small and the parameters can be considered to be independent with each other.

scholarly journals Aerodynamic Performance of Wind Turbine Airfoil DU 91-W2-250 under Dynamic Stall

2018 ◽  
Vol 8 (7) ◽  
pp. 1111 ◽  
Author(s):  
Shuang Li ◽  
Lei Zhang ◽  
Ke Yang ◽  
Jin Xu ◽  
Xue Li
Keyword(s):  
Wind Turbine ◽  
Aerodynamic Performance ◽  
Dynamic Stall ◽  
Wind Turbine Airfoil

scholarly journals Effect of Single-Row and Double-Row Passive Vortex Generators on the Deep Dynamic Stall of a Wind Turbine Airfoil

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2535
Author(s):  
Chengyong Zhu ◽  
Tongguang Wang ◽  
Jie Chen ◽  
Wei Zhong
Keyword(s):  
Wind Turbine ◽  
Flow Separation ◽  
Aerodynamic Performance ◽  
Vortex Generators ◽  
Dynamic Stall ◽  
Aerodynamic Forces ◽  
Double Row ◽  
Single Row ◽  
Maximum Angle ◽  
Wind Turbine Airfoil

Passive vortex generators (VGs) have been widely applied on wind turbines to boost the aerodynamic performance. Although VGs can delay the onset of static stall, the effect of VGs on dynamic stall is still incompletely understood. Therefore, this paper aims at investigating the deep dynamic stall of NREL S809 airfoil controlled by single-row and double-row VGs. The URANS method with VGs fully resolved is used to simulate the unsteady airfoil flow. Firstly, both single-row and double-row VGs effectively suppress the flow separation and reduce the fluctuations in aerodynamic forces when the airfoil pitches up. The maximum lift coefficient is therefore increased beyond 40%, and the onset of deep dynamic stall is also delayed. This suggests that deep dynamic-stall behaviors can be properly controlled by VGs. Secondly, there is a great difference in aerodynamic performance between single-row and double-row VGs when the airfoil pitches down. Single-row VGs severely reduce the aerodynamic pitch damping by 64%, thereby undermining the torsional aeroelastic stability of airfoil. Double-row VGs quickly restore the decreased aerodynamic efficiency near the maximum angle of attack, and also significantly accelerate the flow reattachment. The second-row VGs can help the near-wall flow to withstand the adverse pressure gradient and then suppress the trailing-edge flow separation, particularly during the downstroke process. Generally, double-row VGs are better than single-row VGs concerning controlling deep dynamic stall. This work also gives a performance assessment of VGs in controlling the highly unsteady aerodynamic forces of a wind turbine airfoil.

Using Kriging Surrogate Models to Predict the Vibration Responses of a Submerged Riser

2020 ◽  
Author(s):  
Marcelo Damasceno ◽  
Hélio Ribeiro Neto ◽  
Tatiane Costa ◽  
Aldemir Cavalini Júnior ◽  
Ludimar Aguiar ◽  
...  
Keyword(s):  
Surrogate Model ◽  
High Performance ◽  
Computational Cost ◽  
Offshore Structures ◽  
Surrogate Models ◽  
Computational Time ◽  
Kriging Surrogate Model ◽  
Efficient Manner ◽  
Modeling Tools ◽  
Fluid Structure

Abstract Fluid-structure interaction modeling tools based on computational fluid dynamics (CFD) produce interesting results that can be used in the design of submerged structures. However, the computational cost of simulations associated with the design of submerged offshore structures is high. There are no high-performance platforms devoted to the analysis and optimization of these structures using CFD techniques. In this context, this work aims to present a computational tool dedicated to the construction of Kriging surrogate models in order to represent the time domain force responses of submerged risers. The force responses obtained from high-cost computational simulations are used as outputs for training and validated the surrogate models. In this case, different excitations are applied in the riser aiming at evaluating the representativeness of the obtained Kriging surrogate model. A similar investigation is performed by changing the number of samples and the total time used for training purposes. The present methodology can be used to perform the dynamic analysis in different submerged structures with a low computational cost. Instead of solving the motion equation associated with the fluid-structure system, a Kriging surrogate model is used. A significant reduction in computational time is expected, which allows the realization of different analyses and optimization procedures in a fast and efficient manner for the design of this type of structure.

Horizontal Axis Wind Turbine Numerical Simulation of Two Dimensional Angle of Attack

2012 ◽  
Vol 619 ◽  
pp. 111-114
Author(s):  
Jing Mei Yu ◽  
Yan Hong Yu ◽  
Pan Pan Liu
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Hot Spot ◽  
The United States ◽  
Aerodynamic Performance ◽  
Horizontal Axis ◽  
Energy Utilization ◽  
Two Dimensional ◽  
Horizontal Axis Wind Turbine ◽  
Wind Turbine Airfoil

wind power is the most effective form of wind energy utilization, modern large-scale wind turbine with horizontal axis wind mainly. Horizontal axis wind turbine aerodynamic performance calculation of the wind turbine aerodynamics research hot spot, is a wind turbine aerodynamic optimization design and calculation of critical load. Horizontal axis wind turbine airfoil aerodynamic performance of the wind turbine operation characteristics and life plays a decisive role". Using Fluent software on the horizontal axis wind turbine numerical simulation, analysis of the United States of America S809NREL airfoil aerodynamic characteristics of different angles of attack numerical simulation, analyzes the different angles of attack in the vicinity of the pressure, velocity distribution. By solving the two-dimensional unsteady, compressible N-S equations for the calculation of wind turbine airfoil S809used the characteristics of flow around. N-S equation in body-fitted coordinate system is given, with the Poisson equation method to generate the C grid.

Research on Improved Method of Wind Turbine Airfoil S834 Based on Noise and Aerodynamic Performance

2015 ◽  
Vol 744-746 ◽  
pp. 253-258 ◽  
Author(s):  
Ya Qiong Chen ◽  
Yue Fa Fang
Keyword(s):  
Wind Turbine ◽  
Optimization Design ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Parametric Modeling ◽  
Multi Objective ◽  
Wind Turbine Airfoil ◽  
Drag Ratio ◽  
Operating Points ◽  
Lift To Drag Ratio

In this paper, aerodynamic performance and noise of the wind turbine airfoil are the optimization design goal and based on this, the optimization design method with multi-operating points and multi-objective of the airfoils is built. The Bezier curve is used in parametric modeling of the contour of the airfoil and the general equation for control points is deduced form the discrete points coordinates of the airfoil. The weigh distribution schemes for multi-objective and multi-operating points are integrated designed by treating the NREL S834 airfoil as the initial airfoils. The results show that the lift-to-drag ratio of the optimized airfoils has a improvement around the designed operating angle and the overall noise has a reduction compared with the initial airfoils, which means that the optimized airfoils get a better aerodynamic and acoustic performance.

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