CISM COURSES AND LECTURES Series Editors: The Rectors of CISM Sandor Kaliszky - Budapest Mahir Sayir - Zurich Wilhelm Schneider - Wien The Secretary General of CISM Giovanni Bianchi - Milan Executive Editor Carlo Tasso - Udine The series presents lecture notes, monographs, edited works and proceedings in the field of Mechanics, Engineering, Computer Science and Applied Mathematics. Purpose of the series is to make known in the international scientific and technical community results obtained in some of the activities organized by CISM, the International Centre for Mechanical Sciences.
INTERNATIONAL CENTRE FOR MECHANICAL SCIENCES COURSES AND LECTURES - No. 369 CONTROL OF FLOW INSTABILITIES AND UNSTEADY FLOWS EDITED BY G.E.A. MEIER DLR INSTITUTE FOR FLUID MECHANICS G.H. SCHNERR UNIVERSITY OF KARLSRUHE ~~ Springer-Verlag Wien GmbH
Le spese di stampa di questo volume sono in parte coperte da contributi del Consiglio Nazionale delle Ricerche. This volume contains 140 illustrations This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks. 1996 by Springer-Verlag Wien Originally published by Springer-Verlag Wien.New York in 1996 In order to make this volume available as economically and as rapidly as possible the authors' typescripts have been reproduced in their original forms. This method unfortunately has its typographical limitations but it is hoped that they in no way distract the reader. ISBN 978-3-211-82807-6 ISBN 978-3-7091-2688-2 (ebook) DOI 10.1007/978-3-7091-2688-2
PREFACE Because most of the practical flow problems are connected with instabilities and the unsteady nature of the flow, concepts of flow control have become of great importance in fundamental research and for the development of advanced technologies in many fields of engineering science. Therefore the study and understanding of the stability of complex flows, which has occupied nearly the whole century and has not come to an end, is a major focus of current research in theoretical and applied fluid mechanics, especially in aerodynamics. From the beginning of this research there was also an attempt to overcome the practical and technical problems connected with these peculiarities. The present volume contains the lecture notes presented during a course at the International Centre for Mechanical Sciences in Udine. Topics covered by these lecture notes include the problem of receptivity of boundary layers, the instability of shear layers and of compressible flows with exothermic reactions, of chaotic motions, and effective control methods. The aim of this course in this field is to understand, to describe and to predict the physics and the mechanism of control systems and to draw the attention of a wider group of engineers to these attractive techniques to support the transfer of knowledge from aerodynamics to other applications in engineering science. The main applications areas of control are boundary layer and shear layer instabilities, normal shock/boundary layer interaction in transonic flows, separation and wakes, vortex generation and destabilization, gusts and turbulence. Passive methods are considered for flows over bumbs, riblets, slotted walls and spoilers. Active control methods are suction and blowing, sound generation, vibration of surfaces and heating or cooling. The individual
contributions cover theoretical, numerical and experimental investigations including concepts for chaos control. The authors wouid like to thank the members of CISM and in particular Professor Kaliszky, Professor Schneider and Professor Tasso for their advice and continuous support in preparation of the course and of this volume. G.E.A. Meier G.H. Schnerr
CONTENTS Preface Page Developments in Stability Theory by N. Peake... 1 Optimal Control and other Complex Systems Paradigms in the Context of Turbulent Flows by T. Ritz and A. W. Hubler... 43 Control of Laminar-Turbulent Transition for Skin Friction Drag Reduction by D. Arnal... 119 Control of Turbulent Flows for Skin Friction Drag Reduction by E. Coustols... 155 Active Control of Boundary Layer and Separation by G.E.A. Meier... 203 Passive Control of Shock/Boundary Layer Interaction by R. Bohning... 235 Passive Ventilation of Shocks in Steady and Unsteady Internal Flows by G.H. Schnerr... 277 Instabilities of Compressible Flows with Internal Heat Addition by G.H. Schnerr... 293