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55th AIAA Aerospace Sciences Meeting

作者： Carbonell Batlle, E. Pereira, R. Kotsonis, M. de Oliveira, G. Terrassa School of Industrial Aerospace and Audiovisual Engineering Polytechnic University of Catalonia Colom 11 Terrassa08222 Spain Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 Delft2629 HS Netherlands

ISBN: (数字)9781624104473

ISBN: (纸本)9781624104473

This article describes and experimentally evaluates an airfoil design methodology, in which airfoils are designed to be simultaneously suited for wind energy applications and to employ Dielectric Barrier Discharge Plasma Actuators (DBD PA) as active flow control (AFC) devices. The design process is carried out using a multi-objective optimizer solved with a genetic algorithm, which evaluates 150 airfoil candidates along 30 generations to optimize their performance. The airfoil candidate evaluation is done with two cost functions: the wind energy suitability cost function compares the non-actuated airfoil performance with a reference group of airfoils, while the AFC suitability cost function assesses the changes in the CL(named CLauthority) caused by the DBD PA actuation. From the generated airfoils, a candidate is selected and tested experimentally at design and off-design conditions. The parametric study on the experimental airfoil performance includes different wind speeds, DBD voltage amplitude and actuation direction. From multiple off-design condition tests it is possible to observe a maximum actuation efficiency at design condition, since higher voltages applied do not lead to a significant increase of the CLauthority and different wind speeds and actuation direction reduce the actuation efficiency. Additionally, the experimental angle of attack range at which DBD actuation induces lift variations compares well with simulated data, and the predicted trends of the actuator impact are confirmed, even though the experimental dCl is smaller than simulated results. The present article demonstrates the potential of the studied airfoil design process to create the future generation of plasma actuated wind energy airfoils. © 2017 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Wind Energy Plasma Actuator Airfoil Dielectric Barrier Discharge Aerodynamic Performance Active Flow Control multi objective genetic algorithm Wind Turbine Laminar Turbulent Transition Wind Tunnel Tests

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Design of a leading edge morphing based on compliant structures for a twin-prop regional aircraft

Design of a leading edge morphing based on compliant structu...

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AIAA/AHS Adaptive Structures Conference, 2018

作者： De Gaspari, A. Gilardelli, A. Ricci, S. Airoldi, A. Moens, F. Department of Aerospace Science and Technology Politecnico di Milano Via La Masa 34 Milano20156 Italy Aerodynamics Aeroelasticity and Acoustcis Department ONERA The French Aerospace Lab 8 rue des vertugadins Meudon92190 France

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Computation of rarefaction effects on a blunt body in hypersonic flow 55

Computation of rarefaction effects on a blunt body in hypers...

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55th AIAA Aerospace Sciences Meeting

作者： Huang, Guanzheng Agarwal, Ramesh K. Department of Mechanical Engineering and Materials Science Washington University in St. Louis St. LouisMO63130 United States

ISBN: (数字)9781624104473

ISBN: (纸本)9781624104473

High-speed vehicles such as next generation launch vehicles or reusable spacecraft experience different flow regimes during flight due to change in atmospheric density. At high altitude, due to low density the flow becomes rarefied and the rarefaction effects cannot be accurately modeled by the Navier-Stokes equations with no-slip boundary conditions. In low density flow, for predicting the small rarefaction effects, Maxwell suggested the use of slip boundary conditions with Navier-Stokes equations. In this paper, a UDF (User Defined Function) which employs the velocity slip and temperature jump boundary conditions at the wall is applied to the commercial flow solver ANSYS FLUENT with the compressible Reynolds Averaged Navier-Stokes (RANS) equations in conjunction with the Shear-Stress-Transport (SST) k-ω turbulence model to simulate the flow around a blunt body in hypersonic flow. The results of both no-slip condition and slip boundary conditions for flow past an axisymmetric body with Knudsen number Kn = 0.0003354, 0.00838, 0.0167, 0.0418, and 0.1are computed and the effect of rarefaction on heat transfer and drag is analyzed and discussed. In addition, a multi-objective genetic algorithm is used to optimize the shape of the blunt body for minimizing both the drag and heat flux. A Pareto optimal front is obtained for different optimization weights of drag vs. heat transfer for Kn = 0.0167. © 2017 by Guanzheng Huang and Ramesh K. Agarwal.

关键词： Hypersonic Flows Freestream Mach Number Reynolds Averaged Navier Stokes Heat Transfer multi objective genetic algorithm Computational Fluid Dynamics Heat Flux Navier Stokes Equations Reusable Spacecraft Atmospheric Density

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Application of numerical optimisation to support engineering design 58

Application of numerical optimisation to support engineering...

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58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2017

作者： Keskin, Akin Engineering Capability Rolls-Royce plc PO Box 31 DerbyDE24 8BJ United Kingdom

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Savalan: multi objective and homogeneous method for software modules clustering

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JOURNAL OF SOFTWARE-EVOLUTION AND PROCESS 2022年第1期34卷

作者： Arasteh, Bahman Fatolahzadeh, Ahmad Kiani, Farzad Istinye Univ Fac Engn & Nat Sci Dept Software Engn Istanbul Turkey Islamic Azad Univ Dept Comp Engn Tabriz Branch Tabriz Iran

Reverse engineering is used for extracting and understanding software architecture models from source code when the source code is the only available software product. Software module clustering is a reverse engineering method which decomposes software modules into several clusters (subsystems) by using module dependency graph. Finding the best clusters for the modules of software is a multi-objective and NP-hard problem;maximizing the cohesion among the modules, minimizing the coupling among different clusters, and maximizing the software modularization quality are considered as the main objectives of software module clustering. Some of these objectives, such as cohesion and coupling, are in contradiction with each other. Simultaneous improvement of all clustering objectives (cohesion, coupling, modularization quality, size, and number of clusters) is the main goal of this study. In this paper, by capitalizing on multi objective genetic algorithm and a new combination of objective functions, we proposed a homogeneous method, namely, Savalan, for clustering software modules. The proposed method generates high-quality clusters with strong cohesion within clusters and weak connections between clusters for the input source code. The results of conducted experiments on the 14 benchmark programs indicate that simultaneous improvement of all clustering objectives is the main merit of this method. According to the experimental results, the proposed algorithm was able to outperform the previous multi objective methods.

关键词： homogenous clustering module clustering multi objective genetic algorithm software maintenance

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multi-objective Optimization of a Pitch Point Absorber Wave Energy Converter

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WATER 2019年第5期11卷 969页

作者： Alamian, Rezvan Shafaghat, Rouzbeh Safaei, Mohammad Reza Babol Noshirvani Univ Technol Sea Based Energy Res Grp Babol Sar 47148 Iran Ton Duc Thang Univ Inst Computat Sci Div Computat Phys Ho Chi Minh City Vietnam Ton Duc Thang Univ Fac Elect & Elect Engn Ho Chi Minh City Vietnam

In this paper, a pitch point absorber wave energy converter (WEC) is selected in order to be optimized for the wave characteristics of the Caspian Sea. The optimization process is a multi-objective optimization. For achieving the optimal WEC, mean absorbed power should be maximized while the construction cost should be minimized. The submerged surface area of the WEC is selected as a cost parameter. The amount of mean absorbed power depends on the installation site and also the shape of the WEC. For optimizing the shape of the WEC, various shapes are considered which are categorized into three different sections. A multi-objective genetic algorithm is used for optimization of the model, and the NEMOH software is used to simulate the wave-body interaction. The results show that the bottom flat and upside chamfered geometry with X:Y ratio of 10:1 is the best geometry for the desired application. Comparing the results from the final optimized shape with the optimized basic parallelepipedic hull shape reveals that much more extractable power can be achieved with less cost.

关键词： wave energy converter point absorber geometry optimization multi objective genetic algorithm Caspian Sea

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Aerodynamic optimization of a morphing airfoil using energy as an objective

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AIAA JOURNAL 2007年第9期45卷 2113-2124页

作者： Namgoong, Howoong Crossley, William A. Lyrintzis, Anastasios S. Purdue Univ Sch Aeronaut & Astronaut W Lafayette IN 47907 USA

Recent advances in materials science and actuation technologies have raised interest in morphing aircraft that can significantly change shape during flight. The research discussed in this paper focuses upon the shape design of morphing airfoil sections. In the efforts herein, the relative strain energy needed to change from one airfoil shape to another is presented as an additional design objective along with a drag design objective, while constraints are enforced on lift. Solving the resulting multi-objective problem generates a range of morphing airfoil designs that represent the best tradeoffs between aerodynamic performance and morphing energy requirements. From the multi-objective solutions, a designer can select a set of airfoil shapes with a low relative strain energy that requires a small actuation cost and with improved aerodynamic performance at the design conditions.

关键词： Morphing Airfoil Aerodynamic Performance Aerodynamic Configurations XFoil Boundary Layer Transition multi objective genetic algorithm Shape Functions Actuation Mechanisms Newton's Method Mission Adaptive Wings

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multidisciplinary and multifidelity Framework for Evaluating System-of-Systems Capabilities of Unmanned Aircraft

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JOURNAL OF AIRCRAFT 2020年第2期57卷 317-332页

作者： Papageorgiou, Athanasios Olvander, Johan Amadori, Kristian Jouannet, Christopher Linkoping Univ Div Machine Design Dept Management & Engn SE-58183 Linkoping Sweden SAAB Aeronaut Adv Design & Survivabil SE-58188 Linkoping Sweden

The operational environment of aerospace products can have a big impact on their performance, and therefore it is an aspect that should be considered as early as possible in their development process. In this light, this paper presents an analysis and optimization framework that can be used in the development of unmanned aerial vehicles (UAV) in order to efficiently explore the design space when considering system-of-systems (SoS) formulations. In this work, the problem is decomposed with a multilevel architecture, and it is divided into three parts, which enable a multifidelity evaluation of the SoS, constituent systems (CS), and subsystems (SS) levels. To be able to capture the collaboration between different assets at an SoS level the framework includes an in-house tool for performing agent-based simulations, whereas the specifications of each CS are analyzed through a set of basic aeronautical disciplines and a number of SS models. The framework is tested against two surveillance scenarios by considering existing as well as new UAV designs, and overall it is shown that the exploration of SoS enables to identify better capabilities;that the operational environment poses different requirements on all system levels;and that fleet tactics have a profound effect on mission performance.

关键词： Unmanned Aircraft Surrogate Model Electrical Systems Space Exploration Tricycle Landing Gear Fuel Consumption multi objective genetic algorithm Aspect Ratio Turbofan Engines Aircraft Manufacturing

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Mixed-Flow Assembly Line Balancing with Uncertain Assembly times in Remanufacturing

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IFAC-PapersOnLine 2022年第10期55卷 97-102页

作者： Qingtao Liu Jiayao Song Jingxiang Lv Ou Tang Zeyu Zhang Key Laboratory of Road Construction Technology and Equipment of MOE Chang'an University 710064 Xi'an China Division of Production Economics Department of Management and Engineering Linköping University SE-581 83 Linköping Sweden

Remanufacturing has in recent decades become an alternative way for sustainable development to cope with the increasingly resource crisis and environmental pollution problems. The line balancing of remanufacturing is more complex than that of traditional manufacturing due to the uncertainty in the remanufacturing process, especially as the assembly time is uncertain. As a result, the line balancing of the remanufacturing assembly has become a critical issue. This paper evaluates the uncertain assembly time in each station based on an approach of Fuzzy Graphical Evaluation and Review Technology (FGERT) network. A remanufacturing multi-objective mixed-flow assembly model is established by optimizing the cycle time, assembly line smoothing coefficient and balance time loss rate. Then an adaptive bilayer genetic algorithm is proposed to solve the optimization problem. Finally, an example was given to demonstrate the effectiveness of the proposed method. Results show that the production rhythm balance of remanufacturing assembly is significantly improved, and the idle time in each assembly station has been reduced as well. The cycle time of the remanufacturing has reduced from 344s to 336s, with the smoothing coefficient and balance time loss rate of being 8.73 and 1.69% compared to that without assembly line balancing. The proposed method provides a useful tool for improving mixed-flow remanufacturing assembly lines in an electromechanics industry.

关键词： Remanufacturing Mixed-model assembly line Assembly line balancing multi objective genetic algorithm

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Structural Optimization of a Large-Scale 3D-Printed High-Altitude Propeller Blade with Experimental Validation

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JOURNAL OF AIRCRAFT 2024年第6期61卷 1586-1599页

作者： Malim, Ahmed Mourousias, Nikolaos Marinus, Benoit G. De Troyer, Tim Royal Mil Acad B-1000 Brussels Belgium Vrije Univ Brussel B-1050 Brussels Belgium Royal Mil Acad Dept Mech Engn Ave Renaissance 30 B-1000 Brussels Belgium Vrije Univ Brussel Dept Engn Technol Pl Laan 2 B-1050 Brussels Belgium Joint Framework Royal Mil Acad RMA & Vrije Univ Br Dept Mech Engn Ave Renaissance 30 Brussels Belgium Joint Framework RMA & VUB Dept Mech Engn Ave Renaissance 30 Brussels Belgium

This paper presents a structural optimization of a 3D-printed thermoplastic-core propeller blade for high-altitude unmanned aerial vehicles using a genetic algorithm. It aims to minimize the weight of the blade by creating longitudinal holes and spars and to minimize the blade tip deflection during operation at an altitude of 16 km. The objective is to check the validity of a 3D-printed material modeling approach for large-scale and more complex 3D-printed parts, such as hollow twisted blades. The approach is based on attentively selecting the printing parameters that reduce the anisotropy of the 3D-printed parts. The linear isotropic behavior of 3D-printed Polylactic Acid and Acrylonitrile Butadiene Styrene M30 tensile samples, which have been tested at ambient and low temperatures (-60 degrees C), is utilized to numerically predict the experimental deformation and natural frequencies of 3D-printed substitute and twisted full blades with good accuracy. The validated linear isotropic model of each material is then used to evaluate the objectives and the constraints of the two-objective optimization process using one-way fluid-structure interaction. Four optimized blades have been selected from the Pareto fronts as candidates, printed, and tested in bending and vibration. The numerical and experimental results of the candidate blades in terms of deformation and natural frequencies are in good agreement, proving the validity of the present macroscale approach for large-scale hollow twisted blades.

关键词： Marine Propellers Structural Design and Development Fluid Structure Interaction multi objective genetic algorithm Finite Element Analysis Numerical Simulation Ultimate Tensile Strength Structural Optimization Additive Manufacturing 3D-printed Material Modeling

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