scholarly journals Knowledge-Based Shape Optimization of Morphing Wing for More Efficient Aircraft

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Alessandro De Gaspari ◽  
Sergio Ricci

An optimization procedure for the shape design of morphing aircraft is presented. The process is coupled with a knowledge-based framework combining parametric geometry representation, multidisciplinary modelling, and genetic algorithm. The parameterization method exploits the implicit properties of the Bernstein polynomial least squares fitting to allow both local and global shape control. The framework is able to introduce morphing shape changes in a feasible way, taking into account the presence of structural parts, such as the wing-box, the physical behaviour of the morphing skins, and the effects that these modifications have on the aerodynamic performances. It inherits CAD capabilities of generating 3D deformed morphing shapes and it is able to automatically produce aerodynamic and structural models linked to the same parametric geometry. Dedicated crossover and mutation strategies are used to allow the parametric framework to be efficiently incorporated into the genetic algorithm. This procedure is applied to the shape design of Reference Aircraft (RA) and to the assessment of the potential benefits that morphing devices can bring in terms of aircraft performances. It is adopted for the design of a variable camber morphing wing to investigate the effect of conformal leading and trailing edge control surfaces. Results concerning four different morphing configurations are reported.

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1581
Author(s):  
Alfonso Hernández ◽  
Aitor Muñoyerro ◽  
Mónica Urízar ◽  
Enrique Amezua

In this paper, an optimization procedure for path generation synthesis of the slider-crank mechanism will be presented. The proposed approach is based on a hybrid strategy, mixing local and global optimization techniques. Regarding the local optimization scheme, based on the null gradient condition, a novel methodology to solve the resulting non-linear equations is developed. The solving procedure consists of decoupling two subsystems of equations which can be solved separately and following an iterative process. In relation to the global technique, a multi-start method based on a genetic algorithm is implemented. The fitness function incorporated in the genetic algorithm will take as arguments the set of dimensional parameters of the slider-crank mechanism. Several illustrative examples will prove the validity of the proposed optimization methodology, in some cases achieving an even better result compared to mechanisms with a higher number of dimensional parameters, such as the four-bar mechanism or the Watt’s mechanism.


2009 ◽  
Vol 628-629 ◽  
pp. 13-18
Author(s):  
H.L. Li ◽  
Li Hui Lang ◽  
W. Jiao ◽  
H.Z. Su

Selecting an appropriate preloaded coefficient has always been a challenge in wire- winding prestressed structure optimum design. Cased-based reasoning (CBR) has become a successful technique for knowledge-based systems in many domains. However, hardly any research has addressed the issue of how to generate the adaptation solution when the case has been retrieved. The present paper investigates the adoption of genetic algorithm(GA) to explore the suitable adjustment model. Two adapted model were presented and assessed in terms of their mean relative prediction error rates.The experiment results shown that applying GA to adjust the preloaded coefficient selection model is a feasible approach to largely improve the accuracy of estimation model. It also demonstrate that the adapted CBR presents better estimate accuracy than the results ontained by other unadapted CBR methods.


2014 ◽  
Vol 551 ◽  
pp. 621-625
Author(s):  
Nan Chu Guo

The paper proposes an ideal approach of shape design by using shape evaluation methods accurately. The paper proposes and tests the comprehensive fuzzy evaluation method using a case of two clips based on genetic algorithm and quantitative methods. By using this evaluation method, the shape details of a product could be improved gradually.


Author(s):  
Adel Ghenaiet

This paper presents an evolutionary approach as the optimization framework to design for the optimal performance of a high-bypass unmixed turbofan to match with the power requirements of a commercial aircraft. The parametric analysis had the objective to highlight the effects of the principal design parameters on the propulsive performance in terms of specific fuel consumption and specific thrust. The design optimization procedure based on the genetic algorithm PIKAIA coupled to the developed engine performance analyzer (on-design and off-design) aimed at finding the propulsion cycle parameters minimizing the specific fuel consumption, while meeting the required thrusts in cruise and takeoff and the restrictions of temperatures limits, engine size and weight as well as pollutants emissions. This methodology does not use engine components’ maps and operates on simplifying assumptions which are satisfying the conceptual or early design stages. The predefined requirements and design constraints have resulted in an engine with high mass flow rate, bypass ratio and overall pressure ratio and a moderate turbine inlet temperature. In general, the optimized engine is fairly comparable with available engines of equivalent power range.


2000 ◽  
Vol 36 (4) ◽  
pp. 1927-1931 ◽  
Author(s):  
Ki-Jin Han ◽  
Han-Sam Cho ◽  
Dong-Hyeok Cho ◽  
Hyun-Kyo Jung

2014 ◽  
Vol 496-500 ◽  
pp. 429-435
Author(s):  
Xiao Ping Zhong ◽  
Peng Jin

Firstly, a two-level optimization procedure for composite structure is investigated with lamination parameters as design variables and MSC.Nastran as analysis tool. The details using lamination parameters as MSC.Nastran input parameters are presented. Secondly, with a proper equivalent stiffness laminate built to substitute for the lamination parameters, a two-level optimization method based on the equivalent stiffness laminate is proposed. Compared with the lamination parameters-based method, the layer thicknesses of the equivalent stiffness laminate are adopted as continuous design variables at the first level. The corresponding lamination parameters are calculated from the optimal layer thicknesses. At the second level, genetic algorithm (GA) is applied to identify an optimal laminate configuration to target the lamination parameters obtained. The numerical example shows that the proposed method without considering constraints of lamination parameters can obtain better optimal results.


2015 ◽  
Vol 17 (1) ◽  
Author(s):  
Madeleine Fombad

Background: Law firms in Botswana offer a particularly interesting context to explore the effects of transition in the knowledge economy. Acquiring and leveraging knowledge effectively in law firms through knowledge management can result in competitive advantage; yet the adoption of this approach remains in its infancy. Objectives: This article investigates the factors that will motivate the adoption of knowledge management in law firms in Botswana, and creates an awareness of the potential benefits of knowledge management in these firms.Method: The article uses both quantitative and qualitative research methods and the survey research design. A survey was performed on all 115 registered law firms and 217 lawyers in Botswana. Interviews were conducted with selected lawyers for more insight. Results: Several changes in the legal environment have motivated law firms to adopt knowledge management. Furthermore, lawyers appreciate the potential benefits of knowledge management. Conclusion: With the rise of the knowledge-based economy, coupled with the pressures faced by the legal industry in recent years, law firms in Botswana can no longer afford to rely on the traditional methods of managing knowledge. Knowledge management will, therefore, enhance the cost effectiveness of these firms. Strategic knowledge management certainly helps to prepare law firms in Botswana to be alive to the fact that the systematic harnessing of legal knowledge is no longer a luxury, but an absolute necessity in the knowledge economy. It will also provide an enabling business environment for private sector development and growth and, therefore, facilitate Botswana’s drive towards the knowledge-based economy.


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