Drag Reduction By Shock And Boundary Layer Control

The survival of the Aeronautical Industries of Europe in the highly competitive World Aviation Market is strongly dependent on such factors as time-to-market of a new or derivative aircraft and on its manufacturing costs but also on the achievement of a competitive technological advantage by which an increased market share can be gained. Recognizing this, cooperative research is continuously encouraged and co-financed by the European Union in order to strengthen the scientific and technological base of the Aeronautical Industries thus providing - among others - the technological edge needed for survival. Corresponding targets of research within Area 3, Technologies for Transport Means, and here in particular Area 3A, Aeronautics Technologies, of the Industrial and Materials Technologies Program ( Brite -EuRam III, 1994 -1998) have been identified to be aircraft efficiency, cost effectiveness and environmental impact. Concerning aircraft efficiency - relevant to the present research - a reduction in aircraft drag of 10%, a reduction in aircraft fuel consumption of 30%, and a reduction in airframe, engine and system weight of 20% are envisaged. Meeting these objectives has, of course, also a strong positive impact on the environment.

This volume contains the description of an EC-sponsered program to study all relevant aspects of shock/ boundary-layer interaction control, the latter designed to improve aircraft performance at design (cruise) and off-design conditions. The work being presented includes a discussion of basic control experiments and the corresponding physical modeling, to account for shock control and a discussion of the airfoil experiments conducted for code validation and control assessment, in conjunction with the basic experiments and computations. The contents is comprised of a section giving a broad overview of the research carried out here and more detailed individual contributions by the participants in the research. Der Band enthält den Abschlußbericht eines von EU geförderten Projekts EUROSHOCK, das alle relevanten Aspekte der Kontrolle von Stoßfronten und Grenzschichten (wichtig z.B. für die Verbesserung der Flugeigenschaften von Fluzeugen) untersuchte. Neben einer ausführlichen Diskussion der grundlegenden Kontrollexperimente und der zugrundeliegenden Modellierung werden auch die Versuche an Tragflächen beschrieben, die zur Validierung von Modellrechnungen durchgeführt werden. Darüber hinaus enthält der Band auch die detaillierten Ergebnisse der Teilnehmer an dem Forschungsprogramm.

Timely in two respects: the first is the growing awareness of the need for energy conservation in both transportation and process industries. The second is the recent emergence and application of several viscous drag reduction techniques. Laminar as well as turbulent flows are covered as are active

Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.

With an approach of the velocity of flight of a ship to the velocity of sound, there occurs a considerable increase of the drag. The reason for this must be found in the boundary layer separation caused by formation of shock waves. It will be endeavored to reduce the drag increase by suction of the boundary layer. Experimental results showed that drag increase may be considerably reduced by this method. It was, also, observed that, by suction, the position of shock waves can be altered to a considerable extent.