Airfoil Optimization for Small Wind Turbines Using Multi Objective Genetic Algorithm

2012 ◽  
Author(s):  
Krishnil R. Ram ◽  
Sunil Lal ◽  
M. Rafiuddin Ahmed
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbines ◽  
Lift Coefficient ◽  
Geometric Constraints ◽  
Control Points ◽  
Airfoil Optimization ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Small Wind Turbines ◽  
Horizontal Axis Wind Turbines

Small wind turbines are gaining popularity due to their ability to meet community or domestic needs in isolated areas with relatively easier installation and lower cost than large wind turbines. This study looks at optimizing airfoils for use in small horizontal axis wind turbines. The optimization looks to maximize the lift coefficient (Cl) while minimizing or fixing the drag coefficient (Cd). To satisfy these two objectives a multi–objective genetic algorithm is used. The airfoil is parameterized using a composite Bezier curve with two Bezier segments and 11 control points. Appropriate curvature conditions are implemented at the leading and trailing edge of the airfoil and geometric constraints are applied to maintain the maximum thickness between 8% to 14% of the chord for structural reasons. An existing genetic algorithm (GA) code is modified in C++ to generate suitable airfoils using the 13 control points and pass the coordinates to a solver for analysis. As a result four new airfoils are generated for application in low Reynolds number (Re) flow. The characteristics and suitability of the four airfoils are discussed while comparing them to the popular SG6043 airfoil.

Optimal positioning of wind turbines on Gökçeada using multi-objective genetic algorithm

Wind Energy ◽  
2010 ◽  
Vol 13 (4) ◽  
pp. 297-306 ◽  
Author(s):  
Sedat Şişbot ◽  
Özgü Turgut ◽  
Murat Tunç ◽  
Ünal Çamdalı
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbines ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm

Genetic Algorithm-Based Design of Airfoil for the Root Region of Small Wind Turbines and Performance Analysis With Gurney Flaps

2018 ◽  
Author(s):  
Mohammed Rafiuddin Ahmed ◽  
Krishnil R. Ram ◽  
Bum-Suk Kim ◽  
Sunil P. Lal
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbines ◽  
Lift Coefficient ◽  
Lower Surface ◽  
Trailing Edge ◽  
Gurney Flaps ◽  
Root Region ◽  
Small Wind Turbines ◽  
Drag Ratio ◽  
Lift To Drag Ratio

The root region of small wind turbines experience low Reynolds number (Re) flow that makes it difficult to design airfoils that provide good aerodynamic performance and at the same time, provide structural strength. In the present work, a multi-objective genetic algorithm code was used to design airfoils that are suitable for the root region of small wind turbines. A composite Bezier curve with two Bezier segments and 16 control points (11 of them controlled) was used to parametrize the airfoil problem. Geometric constraints including suitable curvature conditions were enforced to maintain the airfoil thickness between 18% and 22% of chord and a trailing edge thickness of 3% of chord. The objectives were to maximize the lift-to-drag ratio for both clean and soiled conditions. Optimization was done by coupling the flow solver to a genetic algorithm code written in C++, at Re = 200,000 and for angles of attack of 4 and 10 degrees, as the algorithm was found to give smooth variation of lift-to-drag ratio within such a range. The best airfoil from the results was tested in the wind tunnel as well as using ANSYS-CFX. The experimental airfoil had a chord length of 75 mm and was provided with 33 pressure taps. Testing was done for both free and forced transition cases. The airfoil gave the highest lift-to-drag ratio at an angle of 6 degrees with the ratio varying very little between 4 degrees and 8 degrees. Forced transition at 8% of chord did not show significant change in the performance indicating that the airfoil will perform well even in soiled condition. Fixed trailing edge flaps (Gurney flaps) were provided right at the trailing edge on the lower surface. The lift and drag behavior of the airfoil was then studied with Gurney Flaps of 2% and 3% heights, as it was found from previous studies that flap heights of 1% or greater than 3% do not give optimum results. The flaps considerably improved the suction on the upper surface and also improved the pressure on the lower surface, resulting in a higher lift coefficient; at the same time, there was also an increase in the drag coefficient but it was less compared to the increase in the lift coefficient. The results indicate that Gurney flaps can be effectively used to improve the performance of thick trailing edge airfoils designed for the root region of small wind turbines.

Effects of Euler Angles of Vertical Cambered Otter Board on Hydrodynamics Based on Response Surface Methodology and Multi-Objective Genetic Algorithm

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Gang Wang ◽  
Liuyi Huang ◽  
Lei Wang ◽  
Fenfang Zhao ◽  
Xinxin Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Genetic Algorithm ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Center Of Pressure ◽  
Lift Coefficient ◽  
Hydrodynamic Characteristics ◽  
Euler Angles ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm

Abstract In this present work, effects of three Euler angles (angle of attack (AOA), angle of trim (AOT), and angle of pitch (AOP)) of vertical cambered otter board on hydrodynamic characteristics (drag coefficient (Cd), lift coefficient (Cl), center-of-pressure coefficients (Cp)) were studied based on numerical simulation combined with Kriging response surface methodology (KRSM) and multi-objective genetic algorithm (MOGA). Wind tunnel experiments were carried out to validate the accuracy of the response surface based on numerical simulation. It was demonstrated that AOA had noticeable effects on Cd and Cl, while AOT and AOP had fewer effects. The working posture of the otter board was recommended to lean inward (0 deg–6 deg) and forward (−10 deg–0 deg) to improve the lift-drag ratio without sacrificing Cl. The influences of AOT and AOP on positions of center-of-pressure points were less significant than that of AOA and decreasing with the increase of AOA. Besides, the response surface of hydrodynamic coefficients around the critical AOA was a decent indicator of the occurrence of stall. Finally, three candidate cases were selected to satisfy the high working efficiency by MOGA, which was consistent with the above recommendations. This study provided a scientific reference of response surface experimental investigations methodology in the fishery engineering and the configuration of Euler angles of otter board.

scholarly journals Unified Multi-Objective Genetic Algorithm for Energy Efficient Job Shop Scheduling

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Hongjing Wei ◽  
Shaobo Li ◽  
Huafeng Quan ◽  
Dacheng Liu ◽  
Shu Rao ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Energy Efficient ◽  
Job Shop ◽  
Job Shop Scheduling ◽  
Shop Scheduling ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm
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