A Comparison of Airfoil Shape Parameterization Techniques for Early Design Optimization

Author(s):  
Vis Sripawadkul ◽  
Mattia Padulo ◽  
Marin Guenov
2021 ◽  
Author(s):  
Kasimir Forth ◽  
Jimmy Abualdenien ◽  
André Borrmann ◽  
Sabrina Fellermann ◽  
Christian Schunicht

2019 ◽  
Vol 91 (7) ◽  
pp. 1067-1076
Author(s):  
Maxim Tyan ◽  
Jungwon Yoon ◽  
Nhu Van Nguyen ◽  
Jae-Woo Lee ◽  
Sangho Kim

Purpose Major changes of an aircraft configuration are conducted during the early design stage. It is important to include the airworthiness regulations at this stage while there is extensive freedom for designing. The purpose of this paper is to introduce an efficient design framework that integrates airworthiness guidelines and documentation at the early design stage. Design/methodology/approach A new design and optimization process is proposed that logically includes the airworthiness regulations as design parameters and constraints by constructing a certification database. The design framework comprises requirements analysis, preliminary sizing, conceptual design synthesis and loads analysis. A design certification relation table (DCRT) describes the legal regulations in terms of parameters and values suitable for use in design optimization. Findings The developed framework has been validated and demonstrated for the design of a Federal Aviation Regulations (FAR) 23 four-seater small aircraft. The validation results show an acceptable level of accuracy to be applied during the early design stage. The total mass minimization problem has been successfully solved while satisfying all the design requirements and certification constraints specified in the DCRT. Moreover, successful compliance with FAR 23 subpart C is demonstrated. The proposed method is a useful tool for design optimization and compliance verifications during the early stages of aircraft development. Practical implications The new certification database proposed in this research makes it simpler for engineers to access a large amount of legal documentation related to airworthiness regulations and provides a link between the regulation text and actual design parameters and their bounds. Originality/value The proposed design optimization framework integrates the certification database that is built of several types of legal documents such as regulations, advisory circulars and standards. The Engineering Requirements and Guide summarizes all the documents and design requirements into a single document. The DCRT is created as a summary table that indicates the design parameters affected by a given regulation(s), the design stage at which the parameter can be evaluated and its value bounds. The introduction of the certification database into the design optimization framework significantly reduces the engineer’s load related for airworthiness regulations.


Author(s):  
Xudong Zhang ◽  
Hong-Zhong Huang ◽  
Shengkui Zeng ◽  
Zhili Wang

Reliability Based Multidisciplinary Design Optimization (RBMDO) has received increasing attention to reach high reliability and safety in complex and coupled systems. In early design of such systems, however, information is often not sufficient to construct the precise probabilistic distributions required by the RBMDO and consequently RBMDO can not be carried out effectively. The present work proposes a method of Possibility Based Multidisciplinary Design Optimization (PBMDO) within the framework of the Sequential Optimization and Reliability Assessment (PBMDO-SORA). The proposed method enables designers to solve MDO problems without sufficient information on the uncertainties associated with variables, and also to efficiently decrease the computational demand. The efficiency of the proposed method is illustrated with an engineering design.


2018 ◽  
Author(s):  
Ahmed Khalil ◽  
Rajender Agrawal ◽  
Faris Kamal ◽  
Oussama Takieddine

Author(s):  
Tianjiao Dang ◽  
Bingfei Li ◽  
Dike Hu ◽  
Yachuan Sun ◽  
Zhen Liu

An aerodynamic design optimization of a hypersonic rocket sled deflector is presented using the free-form deformation (FFD) technique. The objective is to optimize the aerodynamic shape of the hypersonic rocket sled deflector to increase its negative lift and enhance the motion stability of the rocket sled. The FFD technique is selected as the aerodynamic shape parameterization method, and the continuous adjoint method based on the gradient method is used to search the optimization in the geometric shape parameter space; the computational fluid dynamics method for a hypersonic rocket sled is employed. An automatic design optimization method for the deflector is carried out based on the aerodynamic requirements of the rocket sled. The optimization results show that the optimized deflector meets the design requirement of increasing the negative lift under the constraint of drag. By improving the pressure distribution on the surface of the deflector, the negative lift is increased by 7.39%, which confirms the effectiveness of the proposed method.


2018 ◽  
Vol 2 (2) ◽  
pp. 23-31
Author(s):  
Syed Khawar Nadeem Kirmani ◽  
Raja Noshad Jamil

This paper presents an efficient and intuitive technique of shape parameterization for design optimization using a partial differential equation (PDE) of order ten. It shows how the choice of two introduced parameters can enable one to parameterize complex geometries. With the use of PDE based formulation, it is shown in this paper how the shape can be defined and manipulated on the basis of parameterization and the boundary value approaches by which complex shapes can be created. Further the boundary conditions which are used in it are a boundary and an intermediate curves for defining the shape. This technique allows complex shapes to be parameterized intuitively using a very small set of design parameters. Hence, Practical design optimization of problems becomes more achievable by applying PDE based approach of shape parameterization by incorporating standard numerical optimization techniques.


Author(s):  
Erich Wehrle ◽  
Ilaria Palomba ◽  
Renato Vidoni

Vibrational behavior of epicyclic gearing a critical aspect as this can lead to detrimental structural-mechanical effects including fatigue, comfort and acoustics. In order to better understand this behavior, lumped-parameter models are used in early development phases. Here the eigenfrequencies as well as frequency responses are ascertained with and without consideration of uncertainty. Uncertainty is critical in the early design phases and beyond. In such systems, there is variation in parameter values from a variety of sources. Here the uncertain stiffness will be considered. It is also the goal of this work to dimension the epicyclic gear train to optimize performance. The early design phase is plagued by uncertainty and if this is neglected in the design optimization, this can lead to drastically suboptimal designs. In this work, a methodology is introduced to optimally design and dimension epicyclic gear trains under uncertainty. Though specifically aimed at epicyclic gearing, the methods developed here are general enough for further application fields. Mass and inertia terms are chosen as design variables, though others are possible in this framework. The constraints are so formulated so that the eigenfrequencies avoid the harmonics of the mesh frequencies and its side bands. The uncertain parameters are treated as bounded and therefore intervals are used instead of statistical distributions. Statistical information needed for probabilistic methods of the uncertain parameters are assumed here to be unavailable in early development phases.


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