Optimization and Computational Fluid Dynamics


Book Description

The numerical optimization of practical applications has been an issue of major importance for the last 10 years. It allows us to explore reliable non-trivial configurations, differing widely from all known solutions. The purpose of this book is to introduce the state-of-the-art concerning this issue and many complementary applications are presented.




Aerodynamic Design on Unstructured Grids for Turbulent Flows


Book Description

An aerodynamic design algorithm for turbulent flows using unstructured grids is described. The current approach uses adjoint (costate) variables for obtaining derivatives of the cost function. The solution of the adjoint equations is obtained using an implicit formulation in which the turbulence model is fully coupled with the flow equations when solving for the costate variables. The accuracy of the derivatives is demonstrated by comparison with finite-difference gradients and a few example computations are shown. In addition, a user interface is described which significantly reduces the time required for setting up the design problems. Recommendations on directions of further research into the Navier Stokes design process are made. Anderson, W. Kyle and Bonhaus, Daryl L. Langley Research Center NASA-TM-112867, NAS 1.15:112867 RTOP 522-31-21-01...







Aerodynamic Shape Optimization Via Discrete Adjoint Formulation Using Euler Equations on Unstructured Grids


Book Description

For the optimization process, a constrained nonlinear programming package which uses a sequential quadratic programming algorithm is used. This study presents the process of analytically obtaining the exact discrete sensitivity derivatives and computationally cost-effective algorithms to efficiently use them in a design environment. Storage issues are circumvented by developing algorithms which perform matrix-vector operations during the construction itself. To validate the unstructured shape optimization procedure, an arbitrary symmetrical airfoil is optimized in an inviscid transonic flow regime.




Aerodynamic Shape Optimization of Complex Aircraft Configurations Via an Adjoint Formulation


Book Description

Abstract: "This work describes the implementation of optimization techniques based on control theory for complex aircraft configurations. Here control theory is employed to derive the adjoint differential equations, the solution of which allows for a drastic reduction in computational costs over previous design methods [13, 12, 43, 38]. In our earlier studies [19, 20, 22, 23, 39, 25, 40, 41, 42] it was shown that this method could be used to devise effective optimization procedures for airfoils, wings and wing-bodies subject to either analytic or arbitrary meshes. Design formulations for both potential flows and flows governed by the Euler equations have been demonstrated, showing that such methods can be devised for various governing equations [39, 25]. In our most recent works [40, 42] the method was extended to treat wing-body configurations with a large number of mesh points, verifying that significant computational savings can be gained for practical design problems. In this paper the method is extended for the Euler equations to treat complete aircraft configurations via a new multiblock implementation. New elements include a multiblock-multigrid flow solver, a multiblock-multigrid adjoint solver, and a multiblock mesh perturbation scheme. Two design examples are presented in which the new method is used for the wing redesign of a transonic business jet."







Engineering and Applied Sciences Optimization


Book Description

The chapters which appear in this volume are selected studies presented at the First International Conference on Engineering and Applied Sciences Optimization (OPT-i), Kos, Greece, 4-6 June 2014 and works written by friends, former colleagues and students of the late Professor M. G. Karlaftis; all in the area of optimization that he loved and published so much in himself. The subject areas represented here range from structural optimization, logistics, transportation, traffic and telecommunication networks to operational research, metaheuristics, multidisciplinary and multiphysics design optimization, etc. This volume is dedicated to the life and the memory of Professor Matthew G. Karlaftis, who passed away a few hours before he was to give the opening speech at OPT-i. All contributions reflect the warmth and genuine friendship which he enjoyed from his associates and show how much his scientific contribution has been appreciated. He will be greatly missed and it is hoped that this volume will be received as a suitable memorial to his life and achievements.




Proceedings of the 8th International Conference on Industrial Engineering


Book Description

This book highlights recent findings in industrial, manufacturing and mechanical engineering and provides an overview of the state of the art in these fields, mainly in Russia and Eastern Europe. A broad range of topics and issues in modern engineering is discussed, including the dynamics of machines and working processes, friction, wear and lubrication in machines, surface transport and technological machines, manufacturing engineering of industrial facilities, materials engineering, metallurgy, control systems and their industrial applications, industrial mechatronics, automation and robotics. This book gathers selected papers presented at the 8th International Conference on Industrial Engineering (ICIE), held in Sochi, Russia, in May 2022. The authors are experts in various fields of engineering, and all papers have been carefully reviewed. Given its scope, this book will be of interest to a wide readership, including mechanical and production engineers, lecturers in engineering disciplines, and engineering graduates.