Numerical Evaluation of Optimization Algorithms for Low-Reynolds-Number Aerodynamic Shape Optimization

AIAA Journal ◽  
2005 ◽  
Vol 43 (10) ◽  
pp. 2262-2267 ◽  
Author(s):  
Marc Secanell ◽  
Afzal Suleman
Keyword(s):  
Reynolds Number ◽  
Shape Optimization ◽  
Numerical Evaluation ◽  
Low Reynolds Number ◽  
Optimization Algorithms ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Shape ◽  
Low Reynolds

Adjoint-Based Aerodynamic Shape Optimization for Low Reynolds Number Airfoils

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Juanmian Lei ◽  
Jiandong He
Keyword(s):  
Reynolds Number ◽  
Shape Optimization ◽  
Low Reynolds Number ◽  
Boundary Layer Separation ◽  
Small Scale ◽  
Test Case ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Shape ◽  
Aerial Vehicles ◽  
Low Reynolds

In the past decades, most of the research studies on airfoil shape design and optimization were focused on high Reynolds number airfoils. However, low Reynolds number airfoils have attracted significant attention nowadays due to their vast applications, ranging from micro-aerial vehicles (MAVs) to small-scale unmanned aerial vehicles. For low Reynolds number airfoils, the unsteady effects caused by boundary layer separation cannot be neglected. In this paper, we present an aerodynamic shape optimization framework for low Reynolds number airfoil that we developed based on the unsteady laminar N–S equation and the adjoint method. Finally, using the developed framework, we performed a test case with NACA0012 airfoil as a baseline configuration and the inverse of lift to drag ratio as the cost function. The optimization was carried out at Re = 10,000 and Ma = 0.2. The results demonstrate the effectiveness of the framework.

Numerical shape optimization in Fluid Mechanics at low Reynolds number

2019 ◽  
Author(s):  
Alexis Courtais ◽  
Francois Lesage ◽  
Yannick Privat ◽  
Pascal Frey ◽  
Abderrazak M. Latifi
Keyword(s):  
Reynolds Number ◽  
Fluid Mechanics ◽  
Shape Optimization ◽  
Low Reynolds Number ◽  
Low Reynolds

scholarly journals Aerodynamic Shape Optimization of a Wavy Airfoil for Ultra-Low Reynolds Number Regime in Gliding Flight

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 467
Author(s):  
Hui Tang ◽  
Yulong Lei ◽  
Xingzhong Li ◽  
Ke Gao ◽  
Yanli Li
Keyword(s):  
Reynolds Number ◽  
Shape Optimization ◽  
Stress Component ◽  
Angle Of Attack ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Efficiency ◽  
Aerodynamic Shape ◽  
Pressure Stress ◽  
Continuous Adjoint ◽  
Initial Geometry

The effect of the number of waves and the width of the ridge and valley in chord direction for a wavy airfoil was investigated at the angle of attack of 0 ∘ and Reynolds number of 10 3 through using the two-dimensional direct numerical simulation for four kinds of wavy airfoil shapes. A new method for parameterizing a wavy airfoil was proposed. In comparison with the original corrugated airfoil profile, the wavy airfoils that have more distinct waves show a lower aerodynamic efficiency and the wavy airfoils that have less distinct waves show higher aerodynamic performance. For the breakdown of the lift and drag concerning the pressure stress and friction stress contributions, the pressure stress component is significantly dominant for all wavy airfoil shapes concerning the lift. Concerning the drag, the pressure stress component is about 75 % for the wavy airfoils that have more distinct waves, while the frictional stress component is about 70 % for the wavy airfoils that have less distinct waves. From the distribution of pressure isoline and streamlines around wavy airfoils, it is confirmed that the pressure contributions of the drag are dominant due to high pressure on the upstream side and low pressure on the downside; the frictional contribution of the drag is dominant due to large surface areas of the airfoil facing the external flow. The effect of the angle of attack on the aerodynamic efficiency for various wavy airfoil geometries was studied as well. Aerodynamic shape optimization based on the continuous adjoint approach was applied to obtain as much as possible the highest global aerodynamic efficiency wavy airfoil shape. The optimal airfoil shape corresponds to an increase of 60 % and 62 % over the aerodynamic efficiency and the lift from the initial geometry, respectively, when optimal airfoil has an approximate drag coefficient compared to the initial geometry. Concerning an fixed angle of attack, the optimal airfoil is statically unstable in the range of the angle of attack from − 1 ∘ to 6 ∘ , statically quasi-stable from − 6 ∘ to − 2 ∘ , where the vortex is shedding at the optimal airfoil leading edge. Concerning an angle of attack passively varied due to the fluid force, the optimal airfoil keeps the initial angle of attack value with an initial disturbance, then quickly increases the angle of attack and diverges in the positive direction.

scholarly journals Application of Nontraditional Optimization Techniques for Airfoil Shape Optimization

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. Mukesh ◽  
K. Lingadurai ◽  
U. Selvakumar
Keyword(s):  
Genetic Algorithm ◽  
Simulated Annealing ◽  
Shape Optimization ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Optimization Algorithms ◽  
Optimization Techniques ◽  
Aerodynamic Shape Optimization ◽  
Shape Optimization Problem ◽  
Aerodynamic Shape

The method of optimization algorithms is one of the most important parameters which will strongly influence the fidelity of the solution during an aerodynamic shape optimization problem. Nowadays, various optimization methods, such as genetic algorithm (GA), simulated annealing (SA), and particle swarm optimization (PSO), are more widely employed to solve the aerodynamic shape optimization problems. In addition to the optimization method, the geometry parameterization becomes an important factor to be considered during the aerodynamic shape optimization process. The objective of this work is to introduce the knowledge of describing general airfoil geometry using twelve parameters by representing its shape as a polynomial function and coupling this approach with flow solution and optimization algorithms. An aerodynamic shape optimization problem is formulated for NACA 0012 airfoil and solved using the methods of simulated annealing and genetic algorithm for 5.0 deg angle of attack. The results show that the simulated annealing optimization scheme is more effective in finding the optimum solution among the various possible solutions. It is also found that the SA shows more exploitation characteristics as compared to the GA which is considered to be more effective explorer.

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