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Higher-order boundary-layer solution for unsteady motion of a circular cylinder

Published online by Cambridge University Press:  26 April 2006

Soonil Nam
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA

Abstract

The higher-order boundary-layer solution for an impulsively started circular cylinder with uniform velocity and for an exponentially accelerating cylinder in incompressible, relatively high-Reynolds-number flow of short duration are considered. A perturbation method is employed to linearize the two-dimensional vorticity transport equation by a double series expansion with respect to the Reynolds number and the time. A matched asymptotic expansion is carried out to define the proper boundary conditions between the viscous and inviscid layers for the linearized first-, second-, and third-order boundary-layer equations. Singularities appear in the higher-order approximate solutions to the viscous displacement velocities and skin frictions, which coincide with the singularity of the first-order approximate solution. These singularities have alternating signs and increasing magnitudes, thus attempting to remove the effects of the singularity of the lower-order solution. However, this futile attempt at removing a singularity by superposing even stronger singularities makes the solution worse around the singularity, which shows that the singularity is an artifact of the thin-boundary-layer approximation.

Type
Research Article
Copyright
© 1990 Cambridge University Press

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References

Bar-Lev, M. & Yang, H. T. 1975 Initial flow field over an impulsively started circular cylinder. J. Fluid Mech. 72, 625647.Google Scholar
Blasius, H. 1908 Grenzschichten in Flüssigkeiten mit kleiner Reibung. Z. Math. Phys. 56, 137.Google Scholar
Cebei, T. 1979 The laminar boundary-layer on a circular started impulsively from rest. J. Comput. Phys. 31, 153172.Google Scholar
Collins, W. M. & Dennis, S. C. R. 1973a The initial flow past an impulsively started circular cylinder. Q. J. Mech. Appl. Maths 26, 5375.Google Scholar
Collins, W. M. & Dennis, S. C. R. 1973b Flow past an impulsively started circular cylinder. J. Fluid Mech. 60, 105127.Google Scholar
Cowley, S. J. 1983 Computer extension and analytic continuation of Blasius' expansion for impulsive flow past a circular cylinder. J. Fluid Mech. 135, 389405.Google Scholar
Fox, L. 1957 The Numerical Solution of Two-Point Boundary Problem in Ordinary Differential Equations. Oxford University Press.
Goldstein, S. 1948 On laminar boundary-layer flow near a point of separation. Q. J. Mech. Appl. Maths 1, 4369.Google Scholar
Goldstein, S. & Rosenhead, L. N. 1936 Boundary layer growth. Proc. Camb. Phil. Soc. 32, 392401.Google Scholar
Henkes, R. A. & Veldman, A. E. P. 1987 On the breakdown of the steady and unsteady interacting boundary-layer description. J. Fluid Mech. 179, 513529.Google Scholar
Hommel, M. J. 1983 The laminar unsteady flow of a viscous fluid away from a plane stagnation. J. Fluid Mech. 132, 407416.Google Scholar
Ingham, D. B. 1984 Unsteady separation. J. Comput. Phys. 53, 9099.Google Scholar
Li, Jiachun 1982 Singularity criteria for perturbation series. Scientia Sinica A, vol. 25, 593.Google Scholar
Nam, S. 1988 Higher order boundary-layer solution for unsteady motion of a circular cylinder. Ph.D. thesis, Stanford University, Stanford, CA.
Sears, W. R. & Telionis, D. P. 1971 Unsteady boundary-layer separation. In Recent Research on Unsteady Boundary Layers (ed. E. A. Eichelbrenner), p. 404. Quebec: Laval University Press.
Telionis, D. P. & Tsahalis, D. Th. 1974 Unsteady laminar separation over impulsively moved cylinders. Acta Astronautica 1, 14841505.Google Scholar
van Dommelen, L. L. & Shen, S. F. 1980 The spontaneous generation of singularity in a separation laminar boundary layer, J. Comput. Phys. 38, 125140.Google Scholar
van Dyke, M. 1975 Perturbation Method in Fluid Mechanics. Stanford: Parabolic.
Wang, C. Y. 1967 The flow past a circular cylinder which is started impulsively from rest. J. Math. Phys. 46, 195202.Google Scholar
Wang, K. C. 1979 Unsteady boundary layer separation. MML Tr 79–16c, Martin Marietta Lab., Baltimore.Google Scholar
Watson, E. J. 1955 Boundary-layer growth.. Proc. R. Soc. Lond. A 231, 104116.Google Scholar