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Integrated optimization on aerodynamics-structure coupling and flight stability of a large airplane in preliminary design

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Chinese Journal of Aeronautics 2018年第6期31卷 1258-1272页

作者： Xiaozhe WANG Zhiqiang WAN Zhu LIU Chao YANG School of Aeronautic Science and Engineering Beihang University Key Laboratory of Aircraft Advanced design Technology Ministry of Industry and Information

The preliminary phase is significant during the whole design process of a large airplane because of its enormous potential in enhancing the overall performance. However, classical sequential designs can hardly adapt to modern airplanes, due to their repeated iterations, long periods, and massive computational burdens. Multidisciplinary analysis and optimization demonstrates the capability to tackle such complex design issues. In this paper, an integrated optimization method for the preliminary design of a large airplane is proposed, accounting for aerodynamics, structure, and stability. Aeroelastic responses are computed by a rapid three-dimensional flight load analysis method combining the high-order panel method and the structural elasticity correction. The flow field is determined by the viscous/inviscid iteration method, and the cruise stability is evaluated by the linear small-disturbance theory. Parametric optimization is carried out using genetic algorithm to seek the minimal weight of a simplified plate-beam wing structure in the cruise trim condition subject to aeroelastic, aerodynamic, and stability constraints, and the optimal wing geometry shape, front/rear spar positions, and structural sizes are obtained simultaneously. To reduce the computational burden of the static aeroelasticity analysis in the optimization process, the Kriging method is employed to predict aerodynamic influence coefficient matrices of different aerodynamic shapes. The multidisciplinary analyses guarantee computational accuracy and efficiency, and the integrated optimization considers the coupling effect sufficiently between different disciplines to improve the overall performance, avoiding the limitations of sequential approaches utilized currently.

关键词： Aeroelasticity Integrated optimization Multidisciptinary analysis Large airplane preliminary design

一种评估非接触水下爆炸对海军复合船体影响的设计方法

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哈尔滨工程大学学报（英文版） 2024年第2期23卷 316-326页

作者： F.Mannacio F.Di Marzo M.Gaiotti C.M.Rizzo M.Venturini Italian Navy Naval Support and Experimentation CentreCSSN Viale S.Bartolomeo40019126 La Spezia(Italy) University of Genova Polytechnic SchoolDITEN Via Montallegro116145 Genova(Italy).

Despite the non-contact underwater explosion phenomena(UNDEX)have been studied for decades and several numerical methods have been proposed in literature,its effects on military structures,especially composite ones,are even nowadays matter of *** early design phases,it is not always possible to verify the shock resistance of hull structures modelling the whole phenomenon,in which fluid,gas and solid properties must be properly set in a fully coupled fluid-structure interaction(FSI)numerical *** ones are extremely complex to set,computationally demanding and certainly not suitable for everyday design *** this paper,a simplified finite element(FE)model,easy to use in an early design phase,is ***,the structure and the fluid are *** this approximation,the fluid behaviour is simplified,using special finite elements,available in a commercial software *** choice reduces the computational time and numerical efforts avoiding the problem of combining computational fluid dynamics(CFD)and FE domains and equations in a fully coupled fluid-structure interaction model.A typical parallel body block of a minesweeper is modelled,using two-dimensional multi-layered shell elements to properly account for the composite materials *** the fluid instead,three dimensional volumetric elements,directly coupled to the structural elements,are *** addition,the same calculation is performed,modelling separately fluid in the CFD environment and structures in the finite element ***,realizing a fully coupled fluid-structure interaction *** results obtained by applying both numerical models are compared with the structural response measured on board of a composite ship during a full-scale shock *** simplified proposed procedure provides results in satisfactory agreement with experiments,allowing the validation of the *** are discussed and differences with the real phenomenon and fully coupled CFD+

关键词： Underwater explosions Shock resistance Composites Fluid-structure interaction Experimental analysis Numerical simulation Vulnerability preliminary design

Determination of a suitable set of loss models for centrifugal compressor performance prediction

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Chinese Journal of Aeronautics 2017年第5期30卷 1644-1650页

作者： Elkin I.GUTIERREZ VELASQUEZ Faculty of Mechanical Engineering Universidad Antonio Narino Medellln 050012 Colombia

Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. In this paper, a review and analysis of the major loss mechanisms and loss models, used to determine the efficiency of a single stage centrifugal compressor, and a subsequent examination to determine an appropriate loss correlation set for estimating the isentropic efficiency in preliminary design stages of centrifugal compressors, were developed. Several semi-empirical correlations, commonly used to predict the efficiency of centrifugal compressors, were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correlation set to determine, with good approximation, the isentropic efficiency of single stage compressor. The aim of this study is to provide a suitable loss correlation set for determining the isentropic efficiency of a single stage centrifugal compressor, because, with a large amount of loss mechanisms and correlations available in the literature, it is difficult to ascertain how many and which correlations to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor. As a result of this study, a set of correlations composed by nine loss mechanisms for single stage centrifugal compressors, conformed by a rotor and a diffuser, are specified.

关键词： Centrifugal compressor Efficiency loss Performance prediction preliminary design Turbomachinery

Comparative scoping study report for the extraction of microalgae oils from two subspecies of Chlorella vulgaris

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Clean Energy 2020年第3期4卷 233-246页

作者： Jasmine Kreft Eric Moe Nicholas Garcia Andrew Ross Wayne Seames Chemical Engineering Department University of North Dakota243 Centennial Drive Stop 8155 Grand ForksND 58202USA School of Chemical and Process Engineering University of Leeds209 Clarendon RoadLeedsLS29DTWest YorkshireUK

The production of microalgae as a fatty acid oil resource for use in biofuels production is a widespread research topic at the lab *** contain a higher lipid content on a dry-weight basis compared to oilseeds such as ***,the growth and cultivation cycle of microalgae is 15 days,in comparison to soybeans,for which the cycle occurs once or twice ***,to date,it has been uneconomical to produce microalgae oils in a world-scale facility due to limitations in cultivating microalgae at commercial *** developments suggest that the use of heterotrophic microalgae may be economically feasible for large-scale oil *** assess this feasibility,a comparative scoping study was performed analysing the feasibility of an industrial-scale process plant for the growth and extraction of oil from *** were developed at the preliminary design level using heterotrophic subspecies and autotrophic subspecies of Chlorella *** Class 4 cost estimates and economic analyses were *** study concludes that processes based on heterotrophic microalgae are more likely to reach economic feasibility than processes using autotrophic ***,a few barriers still remain to achieving free-market economic viability.

关键词： algae oil lipids process design heterotrophic microalgae preliminary design economic analysis

design Curves for Mooring Lines of Turret Mooring Systems

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China Ocean Engineering 1997年第4期12卷 387-392页

作者： Gao, J Tan, JH Chen, XH Shanghai Jiao Tong Univ Shanghai 200030 Peoples R China

This paper presents a series of design curves to aid in the selection of turret mooring systems for tankers based Floating Production Storage and Offloading (FPSO) systems. These curves are appropriate to water depths ranging from 100 m to 600 m. The curves can be used as a preliminary design tool, allowing the designer to quickly evaluate alternative mooring system configurations, including the number of mooring lines, the characteristics of chain and wire rope to be deployed and the. initial tension. With a knowledge of the total environmental force and vessel motion characteristics, the designer can determine the appropriate system for closer evaluation.

关键词： turret mooring system mooring line design curve preliminary design

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四川某斜坡地质灾害的稳定性评价与治理

四川某斜坡地质灾害的稳定性评价与治理