检索结果-内蒙古大学图书馆

flutter analysis of Aircraft Wing Using Equivalent-Plate Models with Orthogonal Polynomials

Transactions of Nanjing University of Aeronautics and Astronautics 2015年第5期32卷 508-516页

作者：唐健谢长川杨超 School of Aeronautic Science and Engineering Beihang University

A method of equivalent simplification,using equivalent-plate models(EPMs),is *** is to achieve goals of rapid modeling and effective analysis in structural dynamics and flutter analysis of complex wing *** is on the assumption that the wing structures discussed are composed of skin,beams and ribs,and the different plate units(such as skin,beam web,rib web)are not distinguished in modeling,which is to avoid the complex pre-processing and make it more *** the effect of transverse shear deformation into consideration,the equivalence is based on the first-order shear deformation theory,and it can import the model files of MSC/NASTRAN and process the information to accomplish the equivalent *** Ritz method is applied with the Legendre polynomials,which is used to define the geometry,structure and displacements of the ***,the selection of Legendre polynomials as trial functions brings good accuracy to the modeling and can avoid the *** is in contrast to the EPM method based on the classical plate *** vibration and flutter analysis,the results obtained by using EPM agree well with those obtained by the finite element method,which indicates the accuracy and effectiveness in vibration and flutter analysis of the EPM method.

关键词： equivalent-plate model(EPM) flutter analysis vibration analysis Ritz method orthogonal polynomials

来源：评论

学校读者我要写书评

暂无评论

flutter analysis using unsteady aerodynamics in non-fade form

引用

JOURNAL OF AIRCRAFT 1997年第1期34卷 133-136页

作者： Nissim, E T echnion — Israel Institute of Technology Haifa 32000 Israel

A method in which a p-type flutter anlaysis can be performed using complex equations of motion with absolutely no lag terms and no iterations is presented. It is shown that the combination of complex cofficients, together with a restricted range of k over which these coefficients are fitted, is responsible for the high accuracy obtained. This method can replace the p-k method, and may readily be used to perform routine open/closed-loop flutter calculations or to design control laws using parametric optimization of selected variables. It cannot be used in its present form to design control laws using optimal control theory, since the resulting equations are complex. (AIAA)

关键词： Unsteady Aerodynamics flutter analysis Closed Loop Dynamic Pressure Aerodynamics Optimal Control Stiffness Matrices Angle of Attack Unsteady Transonic Flow Navier Stokes Simulation

来源：评论

学校读者我要写书评

暂无评论

flutter analysis OF BRIDGE DECKS USING LATTICE BOLTZMANN METHOD

引用

ENGINEERING REVIEW 2015年第3期35卷 223-237页

作者： Ketong, L. Aiping, T. Yuejun, L. Hao, Z. Harbin Inst Technol Sch Civil Engn Harbin 150006 Hei Longjiang P Peoples R China

Aiming at using the Lattice Boltzmann Method for flutter analysis of the bridge decks, a fluid-structure interaction algorithm is developed within the framework of multiple -relaxation-time Lattice Boltzmann Method. In the present algorithm, the unsteady fluid dynamics is computed by the extended two-dimensional Lattice Boltzmann Method by incorporating the dynamic Smagorinsky subgrid scale model, while the structure is modelled by an elastically suspended rigid body and its dynamic analysis is performed by using a Runge-Kutta method. A staggered coupling strategy is adopted to couple the fluid solver and the structure solver. To demonstrate the applicability of the presented algorithm, flutter analyses of the Second Forth Road Bridge and the Guama River Bridge are employed. The numerical results are compared with wind tunnel measurements. It is shown that the presented algorithm has a good prediction for the flutter onset velocities of the Forth Road Bridge and the Guama River Bridge and thus indicates, to a certain extent, the applicability of the presented algorithm.

关键词： Lattice Boltzmann Method Bridge decks Fluid-structure interaction Dynamic Smagorinsky subgrid scale model flutter analysis

来源：评论

学校读者我要写书评

暂无评论

flutter analysis OF WING, BOOSTER FIN AND VERTICAL TAIL

FLUTTER ANALYSIS OF WING, BOOSTER FIN AND VERTICAL TAIL

引用

2nd International Conference on Mechanical and Aerospace Engineering (ICMAE 2011)

作者： Vinayagamurthy, G. Parammasivam, K. M. Pillai, S. Nadaraja Anna Univ Madras Inst Technol Dept Aerosp Engg Madras 600025 Tamil Nadu India SRM Univ Dept Aeronaut Engn Madras Tamil Nadu India

ISBN: (纸本)9783037852620

Aerospace vehicles are subjected to various types of severe environmental loads. The basic design criterion includes the minimum weight configuration that results in very flexible structures, which leads to various types of structural interaction problems like flutter, divergence etc. Hence every aerospace vehicle should be analysed for its aeroelastic instabilities. In the present work the flutter analysis of a typical space vehicle was carried out in substructure level with the interface fixed condition. The doublet lattice, zona51 and piston theories are used in the unsteady aerodynamic calculations for the subsonic, supersonic and hypersonic speed regimes. As there is no theoretical procedure for transonic speeds, doublet lattice method has been used in the present analysis. Frequency and damping versus velocity are presented to identify the flutter velocities and the flutter behavior.

关键词： Computational Aeroelasticity flutter analysis Unsteady Aerodynamics

来源：评论

学校读者我要写书评

暂无评论

flutter analysis OF AN EMBEDDED BLADE ROW WITH A HARMONIC BALANCE SOLVER 12

FLUTTER ANALYSIS OF AN EMBEDDED BLADE ROW WITH A HARMONIC BA...

引用

12th European Conference on Turbomachinery (ETC) - Fluid Dynamics and Thermodynamics

作者： Kersken, H-P Frey, C. Ashcroft, G. Schoenenborn, H. German Aerosp Ctr DLR Inst Prop Technol Cologne Germany MTU Aero Engines AG Munich Germany

Commonly, in the flutter analysis of a turbomachine blade row the blade row studied for stability is treated as isolated from its neighbouring blade rows. This approach neglects the effects caused by the reflection of upstream and downstream propagating waves at the neighbouring blade rows. These reflected waves are the source of additional unsteady forces at the blade surface which may have significant effects on the aeroelastic stability of the blade row. To take this influence in the flutter analysis of a blade row into account a coupled unsteady simulation of all rows considered has to be performed. The usual approach to solve for the unsteady flow with a non-linear time-domain solver is expensive in terms of computational resources. Especially if in a multi-row configuration the blade counts of the blade rows considered do not allow restricting the simulation to a few passages in each row. To solve for the unsteady flow field, in this paper an alternative approach based on the nonlinear frequency domain Harmonic Balance method is presented. In the frequency-domain the unsteady flow field can be approximated with a small number of relevant frequencies and the circumferential and temporal periodicity of the problem reduces the computational domain to a single passage per blade row only. The efficiency of this approach for flutter analysis in a multi-row configuration is demonstrated by applying it to an embedded rotor blade row.

关键词： harmonic balance flutter analysis blade row interaction

来源：评论

学校读者我要写书评

暂无评论

flutter analysis with Stabilized Finite Elements based on the Linearized Frequency-domain Approach

Flutter Analysis with Stabilized Finite Elements based on th...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Jacobson, Kevin E. Stanford, Bret K. Wood, Stephen L. Anderson, W. Kyle NASA Langley Res Ctr Hampton VA 23681 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

When designing and certifying aircraft, engineers must take into consideration aeroelastic effects such as flutter. Design and certification of a vehicle may require analysis of thousands of aeroelastic responses. Standard tools in the aerospace industry are based on linear aerodynamic models such as the doublet-lattice method, but these methods can be nonconservative in certain situations such as in the transonic regime. While computational fluid dynamics (CFD) is a higher fidelity alternative, the time-marching approach has a drastically increased computational cost compared to the linear aerodynamic methods. By taking advantage of the periodic nature of flutter, frequency-domain methods offer a more efficient alternative to time-marching CFD. In this work, a linearized frequency-domain method is implemented and verified in the stabilized finite-element solver in FUN3D. The linearized frequency-domain method is demonstrated and compared to other methods for traditional benchmark cases for computational aeroelasticity: the AGARD 445.6 wing, the Benchmark Supercritical Wing, and the Benchmark NACA 0012 Wing.

关键词： Time Domain analysis flutter analysis Supercritical Airfoils FUN3D Aeroelastic Response Prediction Computational Fluid Dynamics Aerospace Industry Reynolds Averaged Navier Stokes Aerodynamic Force Angle of Attack

来源：评论

学校读者我要写书评

暂无评论

LARGE-AMPLITUDE FINITE-ELEMENT flutter analysis OF COMPOSITE PANELS IN HYPERSONIC FLOW

引用

AIAA JOURNAL 1993年第6期31卷 1090-1099页

作者： GRAY, CE MEI, C OLD DOMINION UNIV DEPT MECH ENGN & MECHNORFOLKVA 23508

A finite element approach is presented for determining the nonlinear flutter characteristics of three-dimensional thin laminated composite panels using the full third-order piston, transverse loading, aerodynamic theory. The unsteady, hypersonic, aerodynamic theory and the von Karman large-deflection plate theory are used to formulate the aeroelasticity problem. Nonlinear flutter analyses are performed to assess the influence of the higher order aerodynamic theory on the structure's limit-cycle amplitude and the dynamic pressure of the flow velocity. A solution procedure is presented to solve the nonlinear panel flutter finite element equations. Nonlinear flutter analyses are performed for different boundary support conditions and for various system parameters: aspect ratio a/b;material orthotropic ratio, lamination angle theta, and number of layers;Mach number M;flow mass density to panel mass density ratio mu/M;dynamic pressure lambda;and maximum deflection to thickness ratio c/h. The large-amplitude panel flutter results for the full third-order piston aerodynamic theory are presented to assess the influence of the nonlinear aerodynamic theory.

关键词： flutter analysis Hypersonic Flows Dynamic Pressure Aerodynamic Damping Aspect Ratio Laminated Composites Plate Theory Aeroelastic Stability Thickness Ratio Extended Finite Element Method

来源：评论

学校读者我要写书评

暂无评论

Finite element modal formulation for hypersonic panel flutter analysis with thermal effects

引用

AIAA JOURNAL 2004年第4期42卷 687-695页

作者： Cheng, GF Mei, C Old Dominion Univ Norfolk VA 23529 USA

A finite element time-domain modal formulation for analyzing nonlinear flutter of panels subjected to hypersonic airflow has been developed. Von Karman large deflection plate theory is used for description of the structural nonlinearity, and third-order piston theory is employed to consider the aerodynamic nonlinearity. The thermal loadings of uniformly distributed surface temperatures and temperature gradients through the panel thickness are considered. By the application of the modal truncation technique, the number of governing equations of motion is reduced dramatically so that the computational costs are reduced significantly. All possible types of panel behavior, including flat and stable, buckled but dynamically stable, limit cycle oscillation (LCO), periodic motion, and chaotic motion were observed. Examples of the applications of the proposed methodology were flutter responses of isotropic and composite panels. Special emphasis was placed on the boundary between LCO and chaos and on the route to chaos. Time history, phase plane plot, Poincare map, bifurcation diagram, and Lyapunov exponent are employed in the chaos study. It is found that at low or moderately high dynamic pressures, the fluttering panel typically takes a period-doubling route to evolve into chaos, whereas, at high dynamic pressures, the route generally involves bursts of chaos and rejuvenations of periodic motions.

关键词： flutter analysis Thermal Effects Structural Finite Elements Supersonic Theory Aerodynamic Damping Aerodynamic Flows Numerical Integration Dynamic Pressure Aspect Ratio Turbulent Boundary Layer

来源：评论

学校读者我要写书评

暂无评论

Nonlinear finite element post-flutter analysis of multibay composite panels in supersonic regime

引用

COMPOSITE STRUCTURES 2017年第Nov.期180卷 883-891页

作者： Pacheco, D. R. Q. Marques, F. D. Natarajan, S. Ferreira, A. J. M. Univ Sao Paulo Sao Carlos Sch Engn Sao Carlos SP Brazil Indian Inst Technol Madras Madras Tamil Nadu India Univ Porto Fac Engn Oporto Portugal

This study consists of a numerical investigation on the nonlinear flutter oscillations of composite panels on multiple supports (multibay panels) in high supersonic flow. In contrast to what is done in the majority of studies, direct time-domain integration is used here instead of linearized updated mode approximations or modal decomposition techniques. The main goal is to study the interaction between adjacent bays in the nonlinear regime in order to identify aeroelastic phenomena that are not predicted by the usual single-panel approach. Multiple lamination schemes and multibay arrangements are considered, and new important results have been found. In nearly all cases simulated, severe jump discontinuities have been detected in the limit cycle oscillation amplitudes when the dynamic pressure reaches certain values. Such jumps, observed here for the first time, occur due to the nonlinear coupling between neighboring bays and consist of very abrupt amplitude elevations that happen when there are inversions in the motion phase of one or more bays. Furthermore, this study has been able to show that single-panel analysis may be unsafe for structural design as it drastically underestimates the maximum displacements of the bays located in rear (downwind) positions. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： flutter analysis dynamic pressure Device Panel Structural design bays Supersonic nonlinear chatter FINITE ELEMENT limit cycle oscillation maximum displacement nonlinearity

来源：评论

学校读者我要写书评

暂无评论

Supersonic flutter analysis of wings using an unsteady 3D panel method

引用

COMPUTERS & FLUIDS 2001年第2期30卷 237-256页

作者： Cho, JS Chang, YY Hanyang Univ Sch Mech Engn Seoul 133791 South Korea

A frequency-domain flutter analysis scheme for wings is developed using an unsteady 3D panel method. The unsteady aerodynamic force calculation is based on the s-plane unsteady nonplanar lifting surface method, and a finite element method is used to structurally model the wing. The flutter analysis is done using the normal mode approach and a U-g method in frequency-domain. The U-g procedure requires the generalized aerodynamic forces for a range of reduced frequencies calculated from the aerodynamic module. The method was validated by comparing the generalized aerodynamic forces and the flutter points with other numerical results and measured data for various types of wings. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： flutter analysis Wings panel method supersonic flutter Unsteady

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：