Download or read book Analysis of the Hessian for Aeroelastic Optimization written by Eyal Arian and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of the Hessian for Aerodynamic Optimization written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we analyze inviscid aerodynamic shape optimization problems governed by the full potential and the Euler equations in two and three dimensions. The analysis indicates that minimization of pressure dependent cost functions results in Hessians whose eigenvalue distributions are identical for the full potential and the Euler equations. However the optimization problems in two and three dimensions are inherently different. While the two dimensional optimization problems are well-posed the three dimensional ones are ill-posed. Oscillations in the shape up to the smallest scale allowed by the design space can develop in the direction perpendicular to the flow, implying that a regularization is required. A natural choice of such a regularization is derived. The analysis also gives an estimate of the Hessian's condition number which implies that the problems at hand are ill-conditioned. Infinite dimensional approximations for the Hessians are constructed and preconditioners for gradient based methods are derived from these approximate Hessians. Arian, Eyal and Ta'asan, Shlomo Ames Research Center NAS1-19480...

Download or read book Analysis of the Hessian for Aerodynamic Optimization written by Eyal Arian and published by . This book was released on 1996 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of the Hessian for Aerolastic Optimization written by E. Arian and published by . This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Methods for Optimal Design and Control written by J. Borggaard and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the Second International Workshop on Optimal Design and Control, held in Arlington, Virginia, 30 September-3 Octo ber, 1997. The First Workshop was held in Blacksburg, Virginia in 1994. The proceedings of that meeting also appeared in the Birkhauser series on Progress in Systems and Control Theory and may be obtained through Birkhauser. These workshops were sponsored by the Air Force Office of Scientific Re search through the Center for Optimal Design and Control (CODAC) at Vrrginia Tech. The meetings provided a forum for the exchange of new ideas and were designed to bring together diverse viewpoints and to highlight new applications. The primary goal of the workshops was to assess the current status of research and to analyze future directions in optimization based design and control. The present volume contains the technical papers presented at the Second Workshop. More than 65 participants from 6 countries attended the meeting and contributed to its success. It has long been recognized that many modern optimal design problems are best viewed as variational and optimal control problems. Indeed, the famous problem of determining the body of revolution that produces a minimum drag nose shape in hypersonic How was first proposed by Newton in 1686. Optimal control approaches to design can provide theoretical and computational insight into these problems. This volume contains a number of papers which deal with computational aspects of optimal control.

Download or read book Convergence Estimates for Multidisciplinary Analysis and Optimization written by Eyal Arian and published by . This book was released on 1997 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Approximate Hessian for Accelerated Convergence of Aerodynamic Shape Optimization Problems in an Adjoint based Framework written by Doug Shi-Dong and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "An approximation of the Hessian matrix is developed and used to accelerate the convergence of an adjoint-based aerodynamic shape optimization framework. Exact analytical formulations of the direct-direct, adjoint-direct, adjoint-adjoint, and direct-adjoint Hessian approaches are presented and the equivalence between the adjoint-adjoint and direct-adjoint formulations is demonstrated. An approximation of the Hessian is obtained from the analytical formulation by partially solving first-order sensitivities to reduce computational time, while neglecting second-order sensitivities to ease implementation. Error bounds on the resulting approximation are presented for the first-order sensitivities through perturbation analysis and eigenvalue analysis. The proposed method is first assessed using an inverse design pressure problem for a quasi-one-dimensional Euler flow. Additionally, three-dimensional inviscid transonic test cases are used to demonstrate the effectiveness of the method.Eigenvalue analysis of the Hessian for various test cases will seek to explain the resulting acceleration." --

Download or read book New Design Concepts for High Speed Air Transport written by H. Sobieczky and published by Springer Science & Business Media. This book was released on 1997-05-21 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the challenges, the tools and the concepts for developing economically viable high speed civil transport aircraft under environmental constraints. Computational tools for aircraft design and optimization are outlined and application in an industrial environment is shown for new and innovative case studies.

Download or read book Numerical Methods in Sensitivity Analysis and Shape Optimization written by Emmanuel Laporte and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensitivity analysis and optimal shape design are key issues in engineering that have been affected by advances in numerical tools currently available. This book, and its supplementary online files, presents basic optimization techniques that can be used to compute the sensitivity of a given design to local change, or to improve its performance by local optimization of these data. The relevance and scope of these techniques have improved dramatically in recent years because of progress in discretization strategies, optimization algorithms, automatic differentiation, software availability, and the power of personal computers. Numerical Methods in Sensitivity Analysis and Shape Optimization will be of interest to graduate students involved in mathematical modeling and simulation, as well as engineers and researchers in applied mathematics looking for an up-to-date introduction to optimization techniques, sensitivity analysis, and optimal design.

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1996 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances in Multidisciplinary Analysis and Optimization written by and published by . This book was released on 1989 with total page 1084 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Progress in Aeroelastic Optimization Analytical Versus Numerical Approaches written by Stanford University. Department of Aeronautics and Astronautics and published by . This book was released on 1969 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary is given of recent developments in aeroelastic optimization, with emphasis on difficulties encountered in treating examples numerically by adaptation of techniques from optimal control theory. The elementary problem of finding the unswept wing of least skin mass for fixed torsional divergence speed is used to show how a numerical transition-matrix solution is easily obtained that reproduces accurately the analytical solution. Other problems are then considered to illustrate the application of transition-matrix or gradient methods where solutions are not so easily found. An attempt is made to identify those methods most likely to be successful and to outline some of the difficulties involved in applying them to aeroelastic optimization. (Author).

Download or read book Modern Computational Aeroelasticity written by Min Xu and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-12-07 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides a state-of-art overview of computational methods for nonlinear aeroelasticity and load analysis, focusing on key techniques and fundamental principles for CFD/CSD coupling in temporal domain. CFD/CSD coupling software design and applications of CFD/CSD coupling techniques are discussed in detail as well. It is an essential reference for researchers and students in mechanics and applied mathematics.

Download or read book Sensitivity Analysis and Optimization of Aeroelastic Stability written by Alexander P. Seyranian and published by . This book was released on 1981 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Experiences in Multidisciplinary Analysis and Optimization Part 1 written by and published by . This book was released on 1984 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research in Progress Applied and Numerical Mathematics written by and published by . This book was released on 1996 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Foundations of Aeroelastic Optimization and Some Applications to Continuous Systems written by Jean-Louis Armand and published by . This book was released on 1970 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various optimization problems will be presented here, applications of the general methods developed in optimum control theory (Refs. 3,10,11,12) and based on the Hamiltonian formulation of variational calculus for structural optimization with aeroelastic constraints. The problem, common for all the applications, may be stated in a general form: given a reference structure (cantilever beam or two-dimensional plate) with uniform structural properties and specified aeroelastic requirements (such as a given divergence speed or flutter speed), find the structure with minimal weight satisfying the same requirements. This report will be divided into two parts, the first one dealing with static, the second one with dynamic aeroelastic problems (and more precisely flutter problems). This division is not arbitrary, since two out of the three problems of Part A will be found to have a simple analytical solution confirmed by numerical methods, whereas we have to rely on numerical integration mainly in Part B, the torsional-flutter case being excepted. A very powerful numerical procedure, the transition-matrix algorithm, will be described in detail and applied wherever possible. Its limitations in the more complicated case of panel flutter are emphasized. (Author).