Fluid Dynamics for the Study of Transonic Flow

Author: Heinrich J. Ramm

Publisher: Oxford University Press on Demand

ISBN:

Category: Science

Page: 200

View: 438

This new book leads readers step-by-step through the complexities encountered as moving objects approach and cross the sound barrier. The problems of transonic flight were apparent with the very first experimental flights of scale-model rockets when the disastrous impact of shock waves and flow separations caused the aircraft to spin wildly out of control. Today many of these problems have been overcome, and this book offers an introduction to the transonic theory that has made possible many of these advances. The emphasis is on the most important basic approaches to the solution of transonic problems. The book also includes explanations of common pitfalls that must be avoided. An effort has been made to derive the most important equations of inviscid and viscous transonic flow in sufficient detail so that even novices may feel confident in their problem-solving ability. The use of computer approaches is reviewed, with references to the extensive literature in this area, while the critical shortcomings of an exclusive reliance on computational methods are also described. The book will be valuable to anyone who needs to acquire an understanding of transonic flow, including practicing engineers as well as students of fluid mechanics.

Fluid Dynamics for the Study of Transonic Flow

Author: Heinrich J. Ramm

Publisher: Oxford University Press

ISBN:

Category: Science

Page: 216

View: 177

This new book leads readers step-by-step through the complexities encountered as moving objects approach and cross the sound barrier. The problems of transonic flight were apparent with the very first experimental flights of scale-model rockets when the disastrous impact of shock waves and flow separations caused the aircraft to spin wildly out of control. Today many of these problems have been overcome, and this book offers an introduction to the transonic theory that has made possible many of these advances. The emphasis is on the most important basic approaches to the solution of transonic problems. The book also includes explanations of common pitfalls that must be avoided. An effort has been made to derive the most important equations of inviscid and viscous transonic flow in sufficient detail so that even novices may feel confident in their problem-solving ability. The use of computer approaches is reviewed, with references to the extensive literature in this area, while the critical shortcomings of an exclusive reliance on computational methods are also described. The book will be valuable to anyone who needs to acquire an understanding of transonic flow, including practicing engineers as well as students of fluid mechanics.

Introduction to Computational Fluid Dynamics

Author: Pradip Niyogi

Publisher: Pearson Education India

ISBN:

Category: Computational fluid dynamics

Page: 600

View: 525

Introduction to Computational Fluid Dynamics is a self-contained introduction to a new subject, arising through the amalgamation of classical fluid dynamics and numerical analysis supported by powerful computers. Written in the style of a text book for advanced level B.Tech, M.Tech and M.Sc. students of various science and engineering disciplines. It introduces the reader to finite-difference and finite-volume methods for studying and analyzing linear and non-linear problems of fluid flow governed by inviscid incompressible and compressible Euler equations as also incompressible and compressible viscous flows governed by boundary-layer and Navier-Stokes equations. Simple turbulence modelling has been presented.

Boundary Value Problems for Transonic Flow

Author: Alexander G Kuz'min

Publisher: John Wiley & Sons

ISBN:

Category: Technology & Engineering

Page: 316

View: 597

Transonic flow occurs around moving objects as they approach and cross the sound barrier. Serious problems can occur at this point, such as shock-induced flow separation which can cause the aircraft to spin out of control. Another important practical problem is the achievement of higher aerodynamic performance of aircraft at cruise conditions, which leads to considerable fuel savings. The success in application of numerical methods for simulation of transonic flow and aircraft design depends on developments in the underlying mathematical theory. This book presents a breakthrough in the solvability analysis of boundary value problems, which makes it possible to establish convergence of finite element approximations for shock-free flow and to provide a framework for putting the existing numerical methods on a more sound basis. Also, physical aspects concerned with patterns of formation and propagation of weak shock waves are analysed. This contributes to the understanding of the extreme sensitivity of transonic flow to perturbation of freestream conditions. The developed theoretical knowledge base yields promising concepts of the airfoil design and active flow control by airfoil/wing shape modifications or suction/blowing through a perforated surface. Boundary Value Problems for Transonic Flow * Focuses on Computational Fluid Dynamics. * Addresses practical problems, such as airfoil design and flow control. * Presents developments made in the last two decades. In essence this is a much needed monograph for researchers and engineers in applied mathematics and numerical analysis applied to aerodynamics and for algorithm developers in Computational Fluid Dynamics in the aircraft industry. It gives design engineers the underlying mathematical theory necessary for developing new concepts for airfoil/wing design and flow control.

STAR

Author:

Publisher:

ISBN:

Category: Aeronautics

Page:

View: 370

Frontiers of Computational Fluid Dynamics 2002

Author: David A. Caughey

Publisher: World Scientific

ISBN:

Category: Science

Page: 506

View: 828

This series of volumes on the ?Frontiers of Computational Fluid Dynamics? was introduced to honor contributors who have made a major impact on the field. The first volume was published in 1994 and was dedicated to Prof Antony Jameson; the second was published in 1998 and was dedicated to Prof Earl Murman. The volume is dedicated to Prof Robert MacCormack.The twenty-six chapters in the current volume have been written by leading researchers from academia, government laboratories, and industry. They present up-to-date descriptions of recent developments in techniques for numerical analysis of fluid flow problems, and applications of these techniques to important problems in industry, as well as the classic paper that introduced the ?MacCormack scheme? to the world.

Theory of Transonic Astrophysical Flows

Author: Sandip K Chakrabarti

Publisher: World Scientific

ISBN:

Category: Science

Page: 212

View: 937

This book presents methods of studying transonic flows applicable to various astrophysical circumstances. This is the first book of its kind and efforts have been made to be as thorough as possible. It gives complete mathematical solutions for the study in this area including various shock transitions. For any theoretical astrophysicists this book is expected to be very useful as the formalism discussed can be applied to all the branches. Both axisymmetric and non-axisymmetric flows are studied. Contents:Bondi FlowGeneralized Transonic FlowsHybrid Model FlowsIsothermal Transonic FlowsRotating Winds from Self-Gravitating DisksGeneral Relativistic Transonic FlowsNon-Axisymmetric Spiral FlowsMagnetohydrodynamic Transonic FlowsAstrophysical Jets Readership: Theoretical astrophysicists and fluid dynamicists. Keywords:Black Hole Physics;Accretion Flows;Jets and Outflows;Advective Flows;Astrophysical Shocks;Shock WavesReview: “… includes a great deal of new work that gives the subject a coherence and beauty not previously suspected. The range of application is great and most stimulating.” Foreword by Sir H Bondi

A Study of the Simulation of Flow with Free-stream Mach Number 1 in a Choked Wind Tunnel

Author: John R. Spreiter

Publisher:

ISBN:

Category: Aerodynamics

Page: 36

View: 121

The degree to which experimental results obtained under choking conditions in a wind tunnel with solid walls simulate those associated with an unbounded flow with free-stream Mach number 1 is investigated for the cases of two-dimensional and axisymmetric flows. It is found that a close resemblance does indeed exist in the vicinity of the body, and that the results obtained in this way are generally at least as accurate as those obtained in a transonic wind tunnel with partly open test section. Some of the results indicate, however, that substantial interference effects, particularly those of the wave reflection type, may be encountered under certain conditions, both in choked wind tunnels and in transonic wind tunnels, and that the reduction of these interference effects to acceptable limits may require the use of models of unusually small size.

Computational Fluid Dynamics 2000

Proceedings of the First International Conference on Computational Fluid Dynamics, ICCFD, Kyoto, Japan, 10–14 July 2000

Author: Nobuyuki Satofuka

Publisher: Springer Science & Business Media

ISBN:

Category: Science

Page: 810

View: 170

These proceedings contain a selection of refereed contributions as a source of reference for all those interested in the state of the art in computational fluid dynamics. The conference brings together physicists, mathematicians and engineers to review and share recent advances in the field.

Computational Fluid Dynamics for the 21st Century

Proceedings of a Symposium Honoring Prof. Satofuka on the Occasion of his 60th Birthday, Kyoto, Japan, July 15–17, 2000

Author: Mohamed Hafez

Publisher: Springer Science & Business Media

ISBN:

Category: Technology & Engineering

Page: 413

View: 661

This volume contains new trends of computational fluid dynamics for the 21st century and consists of papers especially useful to the younger generation of scientists and engineers in this field. Topics include cartesian, gridless and higher-order schemes, and flow-visualization techniques.

Aerodynamic Analysis of Lattice Grid Fins in Transonic Flow

Author: Karl S. Orthner

Publisher:

ISBN:

Category: Aerodynamics, Transonic

Page: 106

View: 353

Lattice grid fins have been studied for missile tail control for several years. A lattice grid fin can be described as an unconventional missile control surface comprised of an outer frame supported by an inner lattice grid of lifting surfaces. This unconventional fin design offers favorable lift characteristics at high angle of attack as well as almost zero hinge moments allowing the use of small and light actuators. In addition, they promise good storability for potential tube-launched and internal carriage dispenser-launched applications. The drawback for the lattice grid fins is the high drag and potentially poor radar cross section performance produced by this unconventional control surface configuration. Current research at the United State Air Force's Aeroballistic Research Facility (ARF) at Eglin Air Force Base in Florida has indicated there is a critical transonic Mach number where normal shock waves are believed to be present within some of the grid cells. At this particular Mach number, there is a dynamic instability with severe variations of the pitch moment coefficient. A computational fluid dynamics (CFD) study was conducted to investigate these findings and elucidate the flowfield in the grid fin region. The missile model was numerically modeled in Gridgen and computational tests were run in Fluent. Finally, another fin configuration was developed that produced less drag and similar dynamic stability that the other lattice grid fin configurations tested.

Some Recent Advances in Computational Aerodynamics for Helicopter Applications

Author: W. J. McCroskey

Publisher:

ISBN:

Category: Aerodynamics

Page: 20

View: 785

The growing application of computational aerodynamics to nonlinear helicopter problems is outlined, with particular emphasis on several recent quasi-two dimensional examples that used the thin-layer Navier-Stokes equations and an eddy-viscosity model to approximate turbulence. Rotor blades section characteristics can now be calculated accurately over a wide range of transonic flow conditions. However, a finite-difference simulation of transonic flow conditions. However, a finite-difference simulation of complete flow conditions. However, a finite-difference simulation of the complete flow field about a helicopter in forward flight is not currently feasible, despite the impressive progress that it being made in both two and three dimensions. The principal limitations are today's computer speeds and memories, algorithms and solution methods, grid generation, vortex modeling, structural and aerodynamic coupling, and a shortage of engineers who are skilled in both computational fluid dynamics and helicopter aerodynamics and dynamics. Keywords: Vortex interaction; Helicopter aerodynamics; Unsteady transonic flow.

A Study of the Asymmetric Transonic Flow Past a Sharp Leading Edge

Author: Howard A. Stine

Publisher:

ISBN:

Category: Aerodynamics, Transonic

Page: 70

View: 278

An experimental and theoretical study has been made of the two-dimensional transonic flow past a 12° wedge airfoil with lower surface inclined 13° to the air stream. The experimental portion of the study consists of surveys of the flow field about the leading edge in a closed throat tunnel near choking Mach number by means of an X-ray densitometer. From these surveys various features have been determined; namely, the location of the stagnation point, the location of the sonic line, the size of the separation bubble on the upper surface, and the value of the Mach number at the bubble edge. These features were relatively insensitive to changes in Reynolds number in the range from 1X106 to 3X106 based on chord. The theoretical portion of the study consists of the calculation by relaxation methods of an unbounded, inviscid, two-dimensional flow about a portion of the same body at a free-stream Mach number of exactly unity. The calculations yield a separation bubble on the upper surface which has a shape shown to be compatible with known theoretical conditions for viscous attachment to the upper surface of the body. Agreement between theoretically calculated and the experimentally determined features of the flow was good in regions where the local Mach number was 2 or less. In regions of higher local Mach number the agreement was fair. The theoretically determined Mach number on the bubble edge was 2.80 whereas the experimentally determined value was 2.30. The theoretically determined length of the separation bubble was 1.54-percent chord whereas the experimentally determined length was about 5-percent chord. The theoretically determined location of the stagnation point was 0.16-percent chord from the leading edge whereas the experimentally determined location was at 0.56-percent chord. The experience gained in studying the flow suggests the possibility that the solution obtained is not unique and that another solution in better agreement with experiment might exist.

Challenges in Fluid Dynamics

A New Approach

Author: R.Kh. Zeytounian

Publisher: Springer

ISBN:

Category: Technology & Engineering

Page: 230

View: 828

This monograph presents a synopsis of fluid dynamics based on the personal scientific experience of the author who has contributed immensely to the field. The interested reader will also benefit from the general historical context in which the material is presented in the book. The book covers a wide range of relevant topics of the field, and the main tool being rational asymptotic modelling (RAM) approach. The target audience primarily comprises experts in the field of fluid dynamics, but the book may also be beneficial for graduate students.

Computational Aerodynamics and Fluid Dynamics

An Introduction

Author: Jean-Jacques Chattot

Publisher: Springer Science & Business Media

ISBN:

Category: Mathematics

Page: 194

View: 972

The book gives the reader the basis for understanding the way numerical schemes achieve accurate and stable simulations of physical phenomena. It is based on the finite-difference method and simple problems that allow also the analytic solutions to be worked out. ODEs as well as hyperbolic, parabolic and elliptic types are treated. The book builds on simple model equations and, pedagogically, on a host of problems given together with their solutions.