scholarly journals Shape Optimization of an Airfoil in Ground Effect for Application to WIG Craft

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yilei He ◽  
Qiulin Qu ◽  
Ramesh K. Agarwal
Keyword(s):  
Genetic Algorithm ◽  
Flow Field ◽  
Lift Coefficient ◽  
Ground Effect ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Multiobjective Genetic Algorithm ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper employs a multiobjective genetic algorithm (MOGA) to optimize the shape of a widely used wing in ground (WIG) aircraft airfoil NACA 4412 to improve its lift and drag characteristics, in particular to achieve two objectives, that is, to increase its lift and its lift to drag ratio. The commercial software ANSYS FLUENT is employed to calculate the flow field on an adaptive structured mesh generated by ANSYS ICEM software using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a one equation Spalart-Allmaras (SA) turbulence model. The results show significant improvement in both the lift coefficient and lift to drag ratio of the optimized airfoil compared to the original NACA 4412 airfoil. It is demonstrated that the performance of a wing in ground (WIG) aircraft can be improved by using the optimized airfoil.

scholarly journals Shape Optimization of NREL S809 Airfoil for Wind Turbine Blades Using a Multiobjective Genetic Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yilei He ◽  
Ramesh K. Agarwal
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Optimization Technique ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Multiobjective Genetic Algorithm ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

The goal of this paper is to employ a multiobjective genetic algorithm (MOGA) to optimize the shape of a well-known wind turbine airfoil S809 to improve its lift and drag characteristics, in particular to achieve two objectives, that is, to increase its lift and its lift to drag ratio. The commercially available software FLUENT is employed to calculate the flow field on an adaptive structured mesh using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a two-equationk-ωSST turbulence model. The results show significant improvement in both lift coefficient and lift to drag ratio of the optimized airfoil compared to the original S809 airfoil. In addition, MOGA results are in close agreement with those obtained by the adjoint-based optimization technique.

scholarly journals Effect of Leading-Edge Bulges on Aerodynamic Characteristics of Bionic Wingsail

2021 ◽  
Author(s):  
Chen Li ◽  
Peiting Sun ◽  
Hongming Wang
Keyword(s):  
Stokes Equations ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Suction Surface ◽  
Ansys Fluent ◽  
Navier Stokes Equations ◽  
Extension Direction ◽  
Lift And Drag

The leading-edge bulges along the extension direction are designed on the marine wingsail. The height and the spanwise wavelength of the protuberances are 0.1c and 0.25c, respectively. At Reynolds number Re=5×105, the Reynolds Averaged Navier-Stokes equations are applied to the simulation of the wingsail with the bulges thanks to ANSYS Fluent finite-volume solver based on the SST K-ω models. The grid independence analysis is carried out with the lift and drag coefficients of the wingsail at AOA = 8° and AOA=20°. The results show that while the efficiency of the wingsail is reduced by devising the leading-edge bulges before stall, the bulges help to improve the lift coefficient of the wingsail when stalling. At AOA=22° under the action of the leading-edge tubercles, a convective vortex is formed on the suction surface of the modified wingsail, which reduces the flow loss. So the bulges of the wingsail can delay the stall.

scholarly journals Aerodynamic Performance of Biomimicry Snake-Shaped Airfoil

2019 ◽  
Vol 9 (2) ◽  
pp. 3319-3323
Keyword(s):  
Cross Section ◽  
Lift Coefficient ◽  
Design Parameters ◽  
Drag Forces ◽  
Cross Section Shape ◽  
Section Shape ◽  
Wide Range ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

The cross-section shape and proportionality between geometrical dimensions are the most important design parameters of any lifting surfaces. These parameters affect the amount of the aerodynamic forces that will be generated. In this study, the focus is placed on the snake-cross-section airfoil known as the S-airfoil. It is found that there is a lack of available researches on S-airfoil despite its important characteristics. A parametric study on empty model of the S-airfoil with a cross-section shape that is inspired by the Chrysopelea paradise snake is conducted through numerical simulation. Simulation using 2D-ANSYS FLUENT17 software is used to generate the lift and drag forces to determine the performance of airfoil aerodynamic. Based on the results, the S-airfoil can be improved in performance of aerodynamic by reducing the thickness at certain range, whereby changing the thickness-to-chord ratio from 0.037 to 0.011 results in the increment of lift-to-drag ratio from 2.629 to 3.257. On other hand, increasing the height-to-chord ratio of the S-airfoil will increase maximum lift coefficient but drawback is a wide range of angles of attack regarding maximum lift-to-drag ratio. Encouraging results obtained in this study draws attention to the importance of expanding the research on S-airfoil and its usage, especially in wind energy.

Optimization of Maximum Lift to Drag Ratio on Airfoil Design Based on Artificial Neural Network Utilizing Genetic Algorithm

2014 ◽  
Vol 493 ◽  
pp. 123-128 ◽  
Author(s):  
Ismoyo Haryanto ◽  
Tony Suryo Utomo ◽  
Nazaruddin Sinaga ◽  
Citra Asti Rosalia ◽  
Aditya Pratama Putra
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Artificial Neural Network ◽  
Design Method ◽  
Aerodynamic Characteristics ◽  
Drag Coefficients ◽  
Artificial Neural ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

.This paper deals with an alternative design method of airfoil for wind turbine blade for low wind speed based on combination of smart computing and numerical optimization. In this work, a simulation of Artificial Neural Network (ANN) for determining the relation between airfoil geometry and its aerodynamic characteristics was conducted. First, several airfoil geometries were generated through transformation of complex variables (Joukowski transformation), and then lift and drag coefficients of each airfoil were determined using CFD (Computational Fluid Dynamics). In present study, the ANN training was conducted using airfoil geometry and its aerodynamic characteristics as input and output, respectively. Therefore, lift and drag coefficients can be directly determined only by giving the airfoil geometry without having to perform wind tunnel experiment or numerical computation. Moreover, the optimization was conducted to obtain an airfoil geometry which gives maximum lift to drag ratio (CL/CD) for specific Reynolds number. For this purpose Genetic Algorithm (GA) was applied as optimizer. The results were validated using commercial CFD and it can be shown that the result are satisfactory with error approximately of 6%.

Optimization of Flatback Airfoils for Wind Turbine Blades Using a Multi-Objective Genetic Algorithm

2012 ◽  
Author(s):  
Xiaomin Chen ◽  
Ramesh Agarwal
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Wind Turbine Blades ◽  
Multi Objective ◽  
Artificial Neural Network Ann ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Single Objective

In recent years, the airfoil sections with blunt trailing edge (called flatback airfoils) have been proposed for the inboard regions of large wind-turbine blades because they provide several structural and aerodynamic performance advantages. In a previous paper, ASME ES2010-90373, we employed a single objective genetic algorithm (GA) for shape optimization of flatback airfoils for generating maximum lift to drag ratio. The computational efficiency of GA was significantly enhanced with an artificial neural network (ANN). The commercially available software FLUENT was employed for calculation of the flow field using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a turbulence model. In this paper, we employ a multi-objective GA to optimize the flatback airfoils to achieve two objectives, namely the generation of maximum lift as well as the maximum lift to drag ratio. It is shown that the multi-objective GA optimization can generate superior flatback airfoils compared to those obtained by using single objective GA algorithm.

scholarly journals Lift and Drag Coefficient Map of NACA4415 Airfoil

2021 ◽  
Vol 2076 (1) ◽  
pp. 012066
Author(s):  
Rui Yin ◽  
Jing Huang ◽  
Zhi-Yuan He
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Optimal Angle ◽  
Fluent Software ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract The NACA4415 airfoil was numerically simulated with the help of the Fluent software to analyze its aerodynamic characteristics. Results are acquired as follows: The calculation accuracy of Fluent software is much higher than that of XFOIL software; the calculation result of SST k-ω(sstkw) turbulence model is closest to the experimental value; within a certain range, the larger the Reynolds number is, the larger the lift coefficient and lift-to-drag ratio of the airfoil will be, and the smaller the drag coefficient will be; when the angle of attack is less than the optimal angle of attack, the Reynolds number has less influence on the lift-to-drag coefficient and the lift-to-drag ratio; as the Reynolds number increases, the optimal angle of attack increases slightly, and the applicable angle of attack range for high lift-to-drag ratios becomes smaller.

scholarly journals Effects of Pitching Motion Elements on Aerodynamic Characteristics of Airfoil

2021 ◽  
Vol 2076 (1) ◽  
pp. 012078
Author(s):  
Rui Yin ◽  
Jing Huang ◽  
Zhi-Yuan He
Keyword(s):  
Drag Coefficient ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Initial Angle ◽  
Pitching Motion ◽  
The Difference ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract The aerodynamic characteristics of NACA4412 airfoil with different pitching motion elements were compared and analyzed based on CFD in this research. The results are acquired as follows: the difference between the lift and drag coefficients of the airfoil during pitch up and pitch down motions becomes larger with the increase of the pitching amplitude or initial angle of attack; as the pitching amplitude increases, the lift coefficient grows slightly greater and the drag coefficient grows much greater; as the initial angle of attack increases, the lift coefficient grows much greater and the drag coefficient grows slightly; the smaller the attenuation frequency is, the larger the lift-to-drag ratio of the airfoil will be.

scholarly journals THE EFFECTS OF ANGLE OF ATTACK, REYNOLD NUMBERS AND WINGLET STRUCTURE ON THE PERFORMANCE OF CESSNA 172 SKYHAWK

2018 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Henny Pratiwi
Keyword(s):  
Wind Tunnel ◽  
Drag Force ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Balsa Wood ◽  
Wingtip Vortex ◽  
The One ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This research aims to investigate the effects of angle of attack, Reynold numbers and winglet structure on the performance of Cessna 172 Skyhawk aircraft with winglets variation design. Winglets improve efficiency by diffusing the shed wingtip vortex, which reducing the drag due to lift and improving the wing’s lift over drag ratio. In this research, the specimens are the duplicated of Cesnna 172 Skyhawk wing with 1:40 ratio made of balsa wood. There are three different winglet designs that are compared with the one without winglet. The experiments are conducted in an open wind tunnel to measure the lift and drag force with Reynold numbers of 25,000 and 33,000. It can be concluded that the wings with winglets have higher lift coefficient than wing without winglet for both Reynold numbers. It was also found that all wings with winglets have higher lift-to-drag ratio than wings without winglet where the blended 45o cant angle has the highest value.

scholarly journals Experimental Investigation of a Wing-in-Ground Effect Craft

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. Mobassher Tofa ◽  
Adi Maimun ◽  
Yasser M. Ahmed ◽  
Saeed Jamei ◽  
Agoes Priyanto ◽  
...  
Keyword(s):  
Research Work ◽  
Ground Effect ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Efficiency ◽  
Ground Clearance ◽  
Drag Forces ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Wing In Ground Effect

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

scholarly journals CFD Analysis and Shape Optimization of Airfoils Using Class Shape Transformation and Genetic Algorithm—Part I

2021 ◽  
Vol 11 (9) ◽  
pp. 3791
Author(s):  
Md Tausif Akram ◽  
Man-Hoe Kim
Keyword(s):  
Genetic Algorithm ◽  
Shape Optimization ◽  
Drag Coefficient ◽  
Lift Coefficient ◽  
Phase Iii ◽  
Cfd Analysis ◽  
Shape Transformation ◽  
Stability Parameters ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper presents the parameterization and optimization of two well-known airfoils. The aerodynamic shape optimization investigation includes the subsonic (NREL S-821) and transonic airfoils (RAE-2822). The class shape transformation is employed for parametrization while the genetic algorithm is used for optimization purposes. The absolute scheme of the optimization process is carried out for the minimization of the drag coefficient and maximization of lift to drag ratio. In-house MATLAB code is incorporated with a genetic algorithm to calculate the drag coefficient and lift to drag ratio of the resulting optimized airfoil. The panel method is utilized in genetic algorithm optimization code to calculate pressure distribution, lift coefficient, and lift to drag ratio for optimized airfoil shapes and validates with XFOIL and NREL experimental data. Furthermore, CFD analysis is conducted for both the original (NREL S-821) and optimized airfoil obtained. The present method shows that the optimized airfoil achieved an improvement in lift to drag ratio by 7.4% and 15.9% of S-821 and RAE-2822 airfoil, respectively, by the panel technique method and provides high design desirable stability parameters. These features significantly improve the overall aerodynamic performance of the newly optimized airfoils. Finally, the improved aerodynamics results are reported for the design of turbulence modeling and NREL phase II, Phase III, and Phase VI HAWT blades.

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