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Aerodynamics of oscillating disks and a right-circular cylinder

Published online by Cambridge University Press:  28 March 2006

W. W. Willmarth ,
N. E. Hawk ,
A. J. Galloway  and
F. W. Roos
W. W. Willmarth
Affiliation:
Department of Aerospace Engineering, University of Michigan, Ann Arbor
N. E. Hawk
Affiliation:
Department of Aerospace Engineering, University of Michigan, Ann Arbor
A. J. Galloway
Affiliation:
Department of Aerospace Engineering, University of Michigan, Ann Arbor
F. W. Roos
Affiliation:
Department of Aerospace Engineering, University of Michigan, Ann Arbor
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Abstract

Detailed studies are reported of the free and forced oscillation of disks and a right-circular cylinder constrained to rotate about a fixed diametrical axis passing through the centre of the body and normal to the free-stream direction. When a disk is free to rotate, it oscillates at a definite frequency with slowly varying amplitude and phase. A right-circular cylinder also oscillates at a definite frequency but with rapidly increasing amplitude. When the amplitude becomes large, after a few cycles of oscillation, the cylinder rotates steadily in one direction.

Analogue computer elements, position sensors and a dynamic moment balance were used to study the static restoring moment, dynamic restoring moment, average damping moment, statistical properties of the disk motion and power spectrum of the turbulent moment. The behaviour of the disk and cylinder are explained using the measurements and the theory for random excitation of a linear system. The turbulent exciting moment is caused by the unsteady flow in the wake and can be changed by placing disks and splitter plates in the wake. A model is proposed for the unsteady flow field in the wake behind the disk. The model relates the turbulent moment to the vortex shedding process in the wake.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 27 , Issue 1 , 11 January 1967 , pp. 177 - 207
Copyright
© 1967 Cambridge University Press

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References

Birkhoff, G. & Zarantonello, E. H. 1957 Jets, Wakes and Cavities, pp. 115 and 330. New York: Academic Press.
Davenport, W. B. & Root, W. L. 1958 Random Signals and Noise. New York: McGraw-Hill.
Etkin, B. 1959 Dynamics of Flight. New York: Wiley.
Fung, Y. C. 1955 An Introduction to the Theory of Aeroelasticity. New York: Wiley.
Liepmann, H. W. 1952a On the application of statistical concepts to the buffeting problem J. Aero. Sci. 19, 793.Google Scholar
Liepmann, H. W. 1952b Aspects of the turbulence problem J. Appl. Math. Phys. (ZAMP), 3, 321.Google Scholar
Lin, C. C. 1943 On the motion of a pendulum in a turbulent fluid Quart. Appl. Math. 1, 1.Google Scholar
Potter, J. L., Shapiro, N. M. & Murphree, W. D. 1954 Normal force distributions on right circular cylinders in subsonic flow and supersonic flow. Ordnance Missile Laboratories, Redstone Arsenal Rep. no. 2R4F. See also 1954 J. Aero. Sci. 22, 214.Google Scholar
Smith, A. M. O. 1953 On the motion of a tumbling body J. Aero. Sci. 20, 73.Google Scholar
Willmarth, W. W., Hawk, N. E. & Harvey, R. L. 1963 Steady and unsteady motions and wakes of freely falling disks Phys. Fluids, 7, 197.Google Scholar
Willmarth, W. W. & Hawk, N. E. 1964 Aerodynamics of the free and forced oscillation of a disk at subsonic speeds. Office of Aerospace Research U.S. Air Force, ARL Rep. no. 64–19.Google Scholar