Two-dimensional, High-lift Aerodynamic Optimization Using the Continuous Adjoint Method PDF Download

Author: Sangho Kim
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Roxana M. Greenman
Publisher:
ISBN:
Category :
Languages : en
Pages : 146

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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723469992
Category :
Languages : en
Pages : 142

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Book Description
The high-lift performance of a multi-element airfoil was optimized by using neural-net predictions that were trained using a computational data set. The numerical data was generated using a two-dimensional, incompressible, Navier-Stokes algorithm with the Spalart-Allmaras turbulence model. Because it is difficult to predict maximum lift for high-lift systems, an empirically-based maximum lift criteria was used in this study to determine both the maximum lift and the angle at which it occurs. The 'pressure difference rule, ' which states that the maximum lift condition corresponds to a certain pressure difference between the peak suction pressure and the pressure at the trailing edge of the element, was applied and verified with experimental observations for this configuration. Multiple input, single output networks were trained using the NASA Ames variation of the Levenberg-Marquardt algorithm for each of the aerodynamic coefficients (lift, drag and moment). The artificial neural networks were integrated with a gradient-based optimizer. Using independent numerical simulations and experimental data for this high-lift configuration, it was shown that this design process successfully optimized flap deflection, gap, overlap, and angle of attack to maximize lift. Once the neural nets were trained and integrated with the optimizer, minimal additional computer resources were required to perform optimization runs with different initial conditions and parameters. Applying the neural networks within the high-lift rigging optimization process reduced the amount of computational time and resources by 44% compared with traditional gradient-based optimization procedures for multiple optimization runs. Greenman, Roxana M. Ames Research Center NEURAL NETS; ANGLE OF ATTACK; NAVIER-STOKES EQUATION; LIFT; INCOMPRESSIBLE FLOW; COMPUTERS; AIRFOILS; AERODYNAMIC CONFIGURATIONS; AERODYNAMIC COEFFICIENTS; TURBULENCE MODELS; TRAILING EDGES; SUCTION; GRADIENTS; DRAG; FLAPPING; DEFLECTION; ALGO..

Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Jochen Wild
Publisher: CRC Press
ISBN: 1000532623
Category : Technology & Engineering
Languages : en
Pages : 372

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This book presents a detailed look at high-lift aerodynamics, which deals with the aerodynamic behavior of lift augmentation means from various approaches. After an introductory chapter, the book discusses the physical limits of lift generation, giving the lift generation potential. It then explains what is needed for an aircraft to fly safely by analyzing the high-lift-related requirements for certifying an aircraft. Aircraft needs are also analyzed to improve performance during takeoff, approach, and landing. The book discusses in detail the applied means to increase the lift coefficient by either passive and active high-lift systems. It includes slotless and slotted high-lift flaps, active and passive vortex generating devices, boundary and circulation control, and powered lift. Describing methods that are used to evaluate and design high-lift systems in an aerodynamic sense, the book briefly covers numerical as well as experimental simulation methods. It also includes a chapter on the aerodynamic design of high-lift systems. FEATURES Provides an understanding of the physics of flight during takeoff and landing from aerodynamics to flight performance and from simulation to design Discusses the physical limits of lift generation, giving the lift generation potential Concentrates on the specifics of high-lift aerodynamics to provide a first insight Analyzes aircraft needs to improve performance during takeoff, approach, and landing Focuses on civil transport aircraft applications but also includes the associated physics that apply to all aircraft This book is intended for graduate students in aerospace programs studying advanced aerodynamics and aircraft design. It also serves as a professional reference for practicing aerospace and mechanical engineers who are working on aircraft design issues related to takeoff and landing.

Author: Dominique Thévenin
Publisher: Springer Science & Business Media
ISBN: 3540721533
Category : Technology & Engineering
Languages : en
Pages : 301

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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.

Author: Leifur Leifsson
Publisher: World Scientific
ISBN: 1783266309
Category : Technology & Engineering
Languages : en
Pages : 444

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Book Description
Computer simulations is a fundamental tool of the design process in many engineering disciplines including aerospace engineering. However, although high-fidelity numerical models are accurate, they can be computationally expensive with evaluation time for a single design as long as hours, days or even weeks. Simulation-driven design using conventional optimization techniques may be therefore prohibitive.This book explores the alternative: performing computationally efficient design using surrogate-based optimization, where the high-fidelity model is replaced by its computationally cheap but still reasonably accurate representation: a surrogate. The emphasis is on physics-based surrogates. Application-wise, the focus is on aerodynamics and the methods and techniques described in the book are demonstrated using aerodynamic shape optimization cases. Applications in other engineering fields are also demonstrated.State-of-the-art techniques and a depth of coverage never published before make this a unique and essential book for all researchers working in aerospace and other engineering areas and dealing with optimization, computationally expensive design problems, and simulation-driven design.

Author: M. M. Hafez
Publisher: World Scientific
ISBN: 9812383174
Category : Technology & Engineering
Languages : en
Pages : 708

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"Consists mainly of papers presented at a workshop ... held in Half Moon Bay, California, June 19-21, 2001 ... to honor Dr. Dochan Kwak on the occasion of his 60th birthday ... organized by M. Hafez of University of California Davis and Dong Ho Lee of Seoul National University"--Dedication, p. ix.

Author: Slawomir Koziel
Publisher: Springer Nature
ISBN: 303038926X
Category : Technology & Engineering
Languages : en
Pages : 411

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Book Description
This book discusses surrogate modeling of high-frequency structures including antenna and microwave components. The focus is on constrained or performance-driven surrogates. The presented techniques aim at addressing the limitations of conventional modeling methods, pertinent to the issues of dimensionality and parameter ranges that need to be covered by the surrogate to ensure its design utility. Within performance-driven methodologies, mitigation of these problems is achieved through appropriate confinement of the model domain, focused on the regions promising from the point of view of the relevant design objectives. This enables the construction of reliable surrogates at a fraction of cost required by conventional methods, and to accomplish the modeling tasks where other techniques routinely fail. The book provides a broad selection of specific frameworks, extensively illustrated using examples of real-world microwave and antenna structures along with numerous design examples. Furthermore, the book contains introductory material on data-driven and physics-based surrogates. The book will be useful for the readers working in the area of high-frequency electronics, including microwave engineering, antenna design, microwave photonics, magnetism, especially those that utilize electromagnetic (EM) simulation models in their daily routines. Covers performance-driven and constrained modeling methods, not available in other books to date; Discusses of a wide range of practical case studies including a variety of microwave and antenna structures; Includes design applications of the presented modeling frameworks, including single- and multi-objective parametric optimization.

Author: Omar Darío López Mejia
Publisher: Springer
ISBN: 331962136X
Category : Technology & Engineering
Languages : en
Pages : 118

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Book Description
This book deals with numerical simulations and computations of the turbulent flow around high-lift configurations commonly used in aircraft. It is devoted to the Computational Fluids Dynamics (CFD) method using full Navier-Stokes solvers typically used in the simulation of high-lift configuration. With the increase of computational resources in the aeronautical industry, the computation of complex flows such as the aerodynamics of high-lift configurations has become an active field not only in academic but also in industrial environments. The scope of the book includes applications and topics of interest related to the simulation of high-lift configurations such as: lift and drag prediction, unsteady aerodynamics, low Reynolds effects, high performance computing, turbulence modelling, flow feature visualization, among others. This book gives a description of the state-of-the-art of computational models for simulation of high-lift configurations. It also shows and discusses numerical results and validation of these computational models. Finally, this book is a good reference for graduate students and researchers interested in the field of simulation of high-lift configurations.