Modern Aerodynamic Methods for Direct and Inverse Applications


Book Description

A powerful new monograph from an aerodynamicist reviewing modern conventional aerodynamic approaches, this volume covers aspects of subsonic, transonic and supersonic flow, inverse problems, shear flow analysis, jet engine power addition, engine and airframe integration, and other areas, providing readers with the tools needed to evaluate their own ideas and to implement the newer methods suggested in this book. This new book, by a prolific fluid-dynamicist and mathematician who has published more than twenty research monographs, represents not just another contribution to aerodynamics, but a book that raises serious questions about traditionally accepted approaches and formulations, providing new methods that solve longstanding problems of importance to the industry. While both conventional and newer ideas are discussed, the presentations are readable and geared to advanced undergraduates with exposure to elementary differential equations and introductory aerodynamics principles. Readers are introduced to fundamental algorithms (with Fortran source code) for basic applications, such as subsonic lifting airfoils, transonic supercritical flows utilizing mixed differencing, models for inviscid shear flow aerodynamics, and so on. These are models they can extend to include newer effects developed in the second half of the book. Many of the newer methods have appeared over the years in various journals and are now presented with deeper perspective and integration. This book helps readers approach the literature more critically. Rather than simply understanding an approach, for instance, the powerful "type differencing" behind transonic analysis, or the rationale behind "conservative" formulations, or the use of Euler equation methods for shear flow analysis when they are unnecessary, the author guides and motivates the user to ask why and why not and what if. And often, more powerful methods can be developed using no more than simple mathematical manipulations. For example, Cauchy-Riemann conditions, which are powerful tools in subsonic airfoil theory, can be readily extended to handle compressible flows with shocks, rotational flows, and even three-dimensional wing flowfields, in a variety of applications, to produce powerful formulations that address very difficult problems. This breakthrough volume is certainly a "must have" on every engineer's bookshelf.




A Modern Course in Aeroelasticity


Book Description

Aeroelasticity is the study of flexible structures situated in a flowing fluid. Its modern origins are in the field of aerospace engineering, but it has now expanded to include phenomena arising in other fields such as bioengineering, civil engineering, mechanical engineering and nuclear engineering. The present volume is a teaching text for a first, and possibly second, course in aeroelasticity. It will also be useful as a reference source on the fundamentals of the subject for practitioners. In this third edition, several chapters have been revised and three new chapters added. The latter include a brief introduction to `Experimental Aeroelasticity', an overview of a frontier of research `Nonlinear Aeroelasticity', and the first connected, authoritative account of `Aeroelastic Control' in book form. The authors are drawn from a range of fields including aerospace engineering, civil engineering, mechanical engineering, rotorcraft and turbomachinery. Each author is a leading expert in the subject of his chapter and has many years of experience in consulting, research and teaching.




A Modern Course in Aeroelasticity


Book Description

Areader who achieves a substantial command of the material con tained in this book should be able to read with understanding most of the literature in the field. Possible exceptions may be certain special aspects of the subject such as the aeroelasticity of plates and sheIls or the use of electronic feedback control to modify aeroelastic behavior. The first author has considered the former topic in aseparate volume. The latter topic is also deserving of aseparate volume. In the first portion of the book the basic physical phenomena of divergence, control surface eflectiveness, flutter and gust response of aeronautical vehicles are treated. As an indication of the expanding scope of the field, representative examples are also drawn from the non aeronautical literature. To aid the student who is encountering these phenomena for the first time, each is introduced in the context of a simple physical model and then reconsidered systematicaIly in more compli cated models using more sophisticated mathematics.




Studies in Nonlinear Aeroelasticity


Book Description

The great bulk of the literature on aeroelasticity is devoted to linear models. The oretical work relies heavily on linear mathematical concepts, and experimental results are commonly interpreted by assuming that the physical model behaves in a linear manner. Nevertheless, significant work has been done in nonlinear aero elasticity, and one may expect this trend to accelerate for several reasons: our ability to compute has increased at an astonishing rate; as linear concepts have been assimilated widely, there is a natural increase in interest in the foundations of nonlinear modeling; and, finally, some phenomena long recognized to be of interest, but beyond the effective range of linear models, are now known to be essentially nonlinear in nature. In this volume, an exhaustive review of the literature is not attempted. Rather the emphasis is on fundamental ideas and a representative selection of problems. Despite obvious successes in research on problems of aeroelasticity and the existence of a broad literature, including a number of excellent monographs, up to now little attention has been devoted to a general nonlinear theory of interac tion. For the most part nonlinearity has been considered either solely in the description of the behavior of a shell or in the description of the motion of a gas.




NASA Technical Note


Book Description




Recent Advances in Aerodynamics


Book Description

The Joint Institute for Aeronautics and Acoustics at Stanford University was established in October 1973 to provide an academic environment for long-term cooperative research between Stanford and NASA Ames Research Center. Since its establishment, the In stitute has wnducted theoretical and experimental work in the areas of aerodynamics, acoustics, fluid mechanics, flight dynamics, guid ance and control, and human factors. This research has involved Stanford faculty, research associates, graduate students, and many distinguished visitors in collaborative efforts with the research staff of NASA Ames Research Center. The occasion of the Institute's tenth anniversary was used to reflect back on where that research has brought us, and to consider where our endeavors should be directed next. Thus, an International Symposium was held to review recent advances in the fields relevant to the activities of the Institute and to discuss the areas of research to be undertaken in the future. This anniversary was also chosen a.."1 an opportunity to honor one of the Institute's founders and its di rector, Professor Krishnamurty Karamcheti. It has been his creative inspiration that has provided the ideal research environment at the Joint Institute. The International Symposium on Recent Advances in Aero dynamics and Aconstics was held at Stanford University, Stanford, California, U.S.A., August 22-26, 198:~. Thirty-five distinguished scientists were invited to present a comprehensive review on the fol lowing subject areas: unsteady aerodynamics, jets and shear layers, V /STOL aircraft aerodynamics, rotor dynamics and aerodynamics,.







New Results in Numerical and Experimental Fluid Mechanics V


Book Description

This volume collects contributions to the 14th Symposium of the STAB (German Aerospace Aerodynamics Association). The association involves German scientists and engineers from universities, research establishments and industry who are doing research and project work in numerical and experimental fluid mechanics and aerodynamics, mainly for aerospace but for other applications, too. The volume gives a broad overview of ongoing work in Germany in this field.







A Modern Course in Aeroelasticity


Book Description

This book is the sixth edition. It is suitable for one or more courses at the advanced undergraduate level and graduate level to cover the field of aeroelasticity. It is also of value to the research scholar and engineering practitioner who wish to understand the state of the art in the field. This book covers the basics of aeroelasticity or the dynamics of fluid–structure interaction. While the field began in response to the rapid development of aviation, it has now expanded into many branches of engineering and scientific disciplines and treats physical phenomena from aerospace engineering, bioengineering, civil engineering, and mechanical engineering in addition to drawing the attention of mathematicians and physicists. The basic questions addressed are dynamic stability and response of fluid structural systems as revealed by both linear and nonlinear mathematical models and correlation with experiment. The use of scaled models and full-scale experiments and tests play a key role where theory is not considered sufficiently reliable.