Integrated Evolutionary Algorithms/Computational Fluid Dynamics for Drag Reduction in Highway Design

2021 ◽  
Vol 27 (3) ◽  
pp. 04021025
Author(s):  
Peng Zhang ◽  
Anh-Vu Vo ◽  
Debra F. Laefer ◽  
Maurizio Porfiri
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Evolutionary Algorithms ◽  
Drag Reduction ◽  
Highway Design

scholarly journals Variable cant angle winglets for improvement of aircraft flight performance

Meccanica ◽  
2020 ◽  
Vol 55 (10) ◽  
pp. 1917-1947
Author(s):  
J. E. Guerrero ◽  
M. Sanguineti ◽  
K. Wittkowski
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Fuel Efficiency ◽  
Aerodynamic Performance ◽  
Flight Performance ◽  
Sweep Angle ◽  
Aircraft Flight ◽  
Induced Drag ◽  
Aircraft Performance

Abstract Traditional winglets are designed as fixed devices attached at the tips of the wings. The primary purpose of the winglets is to reduce the lift-induced drag, therefore improving aircraft performance and fuel efficiency. However, because winglets are fixed surfaces, they cannot be used to control lift-induced drag reductions or to obtain the largest lift-induced drag reductions at different flight conditions (take-off, climb, cruise, loitering, descent, approach, landing, and so on). In this work, we propose the use of variable cant angle winglets which could potentially allow aircraft to get the best all-around performance (in terms of lift-induced drag reduction), at different flight phases. By using computational fluid dynamics, we study the influence of the winglet cant angle and sweep angle on the performance of a benchmark wing at Mach numbers of 0.3 and 0.8395. The results obtained demonstrate that by adjusting the cant angle, the aerodynamic performance can be improved at different flight conditions.

Computational Fluid Dynamics (CFD) Simulation of Drag Reduction by Riblets on Automobile

2010 ◽  
Author(s):  
N. N. N. Ghazali ◽  
Y. H. Yau ◽  
A. Badarudin ◽  
Y. C. Lim ◽  
Jane W. Z. Lu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Cfd Simulation ◽  
Computational Fluid Dynamics Cfd

New Evolutionary Techniques for Optimization of Energy Systems Utilizing Computational Fluid Dynamics

2003 ◽  
Author(s):  
Douglas S. McCorkle ◽  
Kenneth M. Bryden
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Evolutionary Algorithms ◽  
Computational Cost ◽  
Solution Space ◽  
Optimization Techniques ◽  
Computational Time ◽  
Feed Forward Neural Network ◽  
Thermal Fluids ◽  
Fluid Systems

Optimization techniques that search a solution space without designer intervention are becoming important tools in the engineering design of many thermal fluid systems. Evolutionary algorithms are among the most robust of these optimization methods because the ability to optimize many designs simultaneously makes evolutionary algorithms less susceptible to premature convergence. However application of evolutionary algorithms to thermal and fluid systems described by high fidelity models (e.g. computational fluid dynamics) has been limited due to the high computational cost of the fitness evaluation. This paper presents a novel technique that combines two technologies used in the optimization of thermal fluids systems. The first is graph based evolutionary algorithms that are implemented to help increase the diversity of the evolving population of designs. The second is an algorithm utilizing a feed forward neural network that develops a stopping criterion for computational fluid dynamics solutions. This reduces the time required for each future evaluation in the evolutionary process and allows for more complex thermal fluids systems to be optimized. In the system examined here the overall reduction in computational time is approximately 8 times.

scholarly journals Remoras pick where they stick on blue whales

2020 ◽  
Vol 223 (20) ◽  
pp. jeb226654
Author(s):  
Brooke E. Flammang ◽  
Simone Marras ◽  
Erik J. Anderson ◽  
Oriol Lehmkuhl ◽  
Abhishek Mukherjee ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Experimental Work ◽  
Ecological Monitoring ◽  
Video Recordings ◽  
Venturi Effect ◽  
Separating Flow ◽  
Dynamics Analyses ◽  
Blue Whales

ABSTRACTAnimal-borne video recordings from blue whales in the open ocean show that remoras preferentially adhere to specific regions on the surface of the whale. Using empirical and computational fluid dynamics analyses, we show that remora attachment was specific to regions of separating flow and wakes caused by surface features on the whale. Adhesion at these locations offers remoras drag reduction of up to 71–84% compared with the freestream. Remoras were observed to move freely along the surface of the whale using skimming and sliding behaviors. Skimming provided drag reduction as high as 50–72% at some locations for some remora sizes, but little to none was available in regions where few to no remoras were observed. Experimental work suggests that the Venturi effect may help remoras stay near the whale while skimming. Understanding the flow environment around a swimming blue whale will inform the placement of biosensor tags to increase attachment time for extended ecological monitoring.

scholarly journals Variable Cant Angle Winglets for Improvement of Aircraft Flight Performance

2019 ◽  
Author(s):  
Joel Guerrero ◽  
Kevin Wittkowski ◽  
Marco Sanguineti
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Fuel Efficiency ◽  
Aerodynamic Performance ◽  
Flight Performance ◽  
Sweep Angle ◽  
Aircraft Flight ◽  
Induced Drag ◽  
Aircraft Performance

Traditional winglets are designed as fixed devices attached at the tips of the wings. The primary purpose of the winglets is to reduce the lift-induced drag, therefore improving aircraft performance and fuel efficiency. However, because winglets are fixed surfaces, they cannot be used to control lift-induced drag reductions or to obtain the largest lift-induced drag reductions at different flight conditions (take-off, climb, cruise, loitering, descent, approach, landing, and so on). In this work, we propose the use of variable cant angle winglets which could potentially allow aircraft to get the best all-around performance (in terms of lift-induced drag reduction), at different flight phases. By using computational fluid dynamics, we study the influence of the winglet cant angle and sweep angle on the performance of a benchmark wing at Mach numbers of 0.3 and 0.8395. The results obtained demonstrate that by adjusting the cant angle, the aerodynamic performance can be improved at different flight conditions.

scholarly journals Aerodynamic Drag Reduction for a Generic Truck Using Geometrically Optimized Rear Cabin Bumps

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Abdellah Ait Moussa ◽  
Justin Fischer ◽  
Rohan Yadav
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Aerodynamic Drag ◽  
Numerical Technique ◽  
Fuel Efficiency ◽  
Orthogonal Arrays ◽  
Promising Strategy ◽  
Vehicle Fuel Efficiency ◽  
Aerodynamic Drag Reduction

The continuous surge in gas prices has raised major concerns about vehicle fuel efficiency, and drag reduction devices offer a promising strategy. In this paper, we investigate the mechanisms by which geometrically optimized bumps, placed on the rear end of the cabin roof of a generic truck, reduce aerodynamic drag. The incorporation of these devices requires proper choices of the size, location, and overall geometry. In the following analysis we identify these factors using a novel methodology. The numerical technique combines automatic modeling of the add-ons, computational fluid dynamics and optimization using orthogonal arrays, and probabilistic restarts. Numerical results showed reduction in aerodynamic drag between 6% and 10%.

Drag Reduction of a Near-Sonic Airplane by Using Computational Fluid Dynamics

AIAA Journal ◽  
2005 ◽  
Vol 43 (9) ◽  
pp. 1870-1877 ◽  
Author(s):  
Wataru Yamazaki ◽  
Kisa Matsushima ◽  
Kazuhiro Nakahashi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction
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