G.E.A. Meier - Böcker

This volume contains the Proceedings of the IUTAM Symposium on Mechanics of Passive and Active Flow Control, held at the DLR, Gottingen, in September 1998. This follows an earlier IUTAM Symposium on Turbulence Management and Relaminarisation which was held in Bangalore in 1987. The 1990s have witnessed significant advances and research activity in the area of flow control/management, triggered by technological applications as well as scientific curiosity in understanding the structure of complex flows. This volume contains both review and contributed papers in the area of flow control, with emphasis on fluid dynamical mechanisms underlying different passive and active control techniques used in a variety of flows such as bumps, roughnesses, riblets, vortex generators, suction blowing, sound and MEMS; issues suchas new control concepts and control strategies are also addressed. The application areas include drag reduction, transition, turbulence and separation, many relevant to aeronautical systems.

Prandtl’s famous lecture with the title “Über Flüssigkeitsbewegung bei sehr kleiner Reibung” was presented on August 12, 1904 at the Third Internationalen Mathematischen Kongress in Heidelberg, Germany. This lecture invented the phrase “Boundary Layer” (Grenzschicht). The paper was written during Prandtl’s first academic position at the University of Hanover. The reception of the academic world to this remarkable paper was at first lukewarm. But Felix Klein, the famous mathematician in Göttingen, immediately realized the importance of Prandtl’s idea and offered him an academic position in Göttingen. There Prandtl became the founder of modern aerodynamics. He was a professor of applied mechanics at the Göttingen University from 1904 until his death on August 15, 1953. In 1925 he became Director of the Kaiser Wilhelm Institute for Fluid Mechanics. He developed many further ideas in aerodynamics, such as flow separation, base drag and airfoil theory, especially the law of the wall for turbulent boundary layers and the instability of boundary layers en route to turbulence. During the fifty years that Prandtl was in the Göttingen Research Center, he made important contributions to gas dynamics, especially supersonic flow theory. All experimental techniques and measurement techniques of fluid mechanics attracted his strong interest. Very early he contributed much to the development of wind tunnels and other aerodynamic facilities. He invented the soap-film analogy for the torsion of noncircular material sections; even in the fields of meteorology, aeroelasticity, tribology and plasticity his basic ideas are still in use.

This volume contributes to one of the most important topics of Fluid Mechanics in future and presents recent research results on control theory and applied control methods. Understanding and handling of control methods of nonlinear systems, typical of Fluid Mechanics, is the key to reduce losses and to improve the efficiency and safety of technical processes.

Prandtl’s famous lecture with the title “Über Flüssigkeitsbewegung bei sehr kleiner Reibung” was presented on August 12, 1904 at the Third Internationalen Mathematischen Kongress in Heidelberg, Germany. This lecture invented the phrase “Boundary Layer” (Grenzschicht). The paper was written during Prandtl’s first academic position at the University of Hanover. The reception of the academic world to this remarkable paper was at first lukewarm. But Felix Klein, the famous mathematician in Göttingen, immediately realized the importance of Prandtl’s idea and offered him an academic position in Göttingen. There Prandtl became the founder of modern aerodynamics. He was a professor of applied mechanics at the Göttingen University from 1904 until his death on August 15, 1953. In 1925 he became Director of the Kaiser Wilhelm Institute for Fluid Mechanics. He developed many further ideas in aerodynamics, such as flow separation, base drag and airfoil theory, especially the law of the wall for turbulent boundary layers and the instability of boundary layers en route to turbulence. During the fifty years that Prandtl was in the Göttingen Research Center, he made important contributions to gas dynamics, especially supersonic flow theory. All experimental techniques and measurement techniques of fluid mechanics attracted his strong interest. Very early he contributed much to the development of wind tunnels and other aerodynamic facilities. He invented the soap-film analogy for the torsion of noncircular material sections; even in the fields of meteorology, aeroelasticity, tribology and plasticity his basic ideas are still in use.