Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-23T18:33:29.075Z Has data issue: false hasContentIssue false

Singularity formation in three-dimensional motion of a vortex sheet

Published online by Cambridge University Press:  26 April 2006

Takashi Ishihara
Affiliation:
Department of Applied Physics, Faculty of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-01, Japan Present address: Department of Mathematics, Faculty of Science, Toyama University, Gofuku, Toyama 930, Japan.
Yukio Kaneda
Affiliation:
Department of Applied Physics, Faculty of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-01, Japan

Abstract

The evolution of a small but finite three-dimensional disturbance on a flat uniform vortex sheet is analysed on the basis of a Lagrangian representation of the motion. The sheet at time t is expanded in a double periodic Fourier series: R1, λ2, t) = (λ1, λ2, 0) + Σn,mAn,m exp[i(nλ1 + δmλ2)], where λ1 and λ2 are Lagrangian parameters in the streamwise and spanwise directions, respectively, and δ is the aspect ratio of the periodic domain of the disturbance. By generalizing Moore's analysis for two-dimensional motion to three dimensions, we derive evolution equations for the Fourier coefficients An,m. The behaviour of An,m is investigated by both numerical integration of a set of truncated equations and a leading-order asymptotic analysis valid at large t. Both the numerical integration and the asymptotic analysis show that a singularity appears at a finite time tc = O(lnε−1) where ε is the amplitude of the initial disturbance. The singularity is such that An,0 = O(tc−1) behaves like n−5/2, while An,±1 = Otc) behaves like n−3/2 for large n. The evolution of A0,m(spanwise mode) is also studied by an asymptotic analysis valid at large t. The analysis shows that a singularity appears at a finite time t = O−1) and the singularity is characterized by A0,2kk−5/2 for large k.

Type
Research Article
Copyright
© 1995 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Batchelor, G. K. 1967 An Introduction to Fluid Dynamics Cambridge University Press.
Baker, G. R., Meiron, D. I. & Orszag, S. A. 1984 Boundary integral methods for axisymmetric and three-dimensional Rayleigh-Taylor instability problems. Physica D 12, 1931.Google Scholar
Birkhoff, G. 1962 Helmholtz and Taylor instability. In Proc. Symp. Appl. Maths XIII. pp. 5576. AMS.
Caflisch, R. E. 1989 Mathematical analysis of vortex dynamics. In Proc. Workshop on Mathematical Aspects of Vortex Dynamics. (ed. R. E. Caflisch), pp. 124. SIAM.
Ishihara, T. & Kaneda, Y. 1994 Spontaneous singularity formation in the shape of vortex sheet in three-dimensional flow. J. Phys. Soc. Japan. 63, 388392.Google Scholar
Kaneda, Y. 1990 A representation of the motion of a vortex sheet in a three-dimensional flow. Phys. Fluids A 2, 458461. (Also presented at the meeting held in July, 1989 at the Research Institute of Mathematical Science, Kyoto University.)Google Scholar
Krasny, R. 1986 A study of singularity formation in a vortex sheet by the point-vortex approximation. J. Fluid Mech. 167, 6593.Google Scholar
Krasny, R. 1990 Computing vortex sheet motion. In Proc. Intl Congr. of Mathematicians II, pp. 15731583. Springer.
Meiron, D. I., Baker, G. R. & Orszag S. A. 1982 Analytical structure of vortex sheet dynamics. Part 1. Kelvin-Helmholtz instability. J. Fluid Mech. 114, 283298.Google Scholar
Moore, D. W. 1979 The spontaneous appearance of a singularity in the shape of an evolving vortex sheet. Proc. R. Soc. Lond. A 365, 105119.Google Scholar
Rosenhead, L. 1931 The formation of vortices from a surface of discontinuity. Proc. R. Soc. Lond. A 134, 170191.Google Scholar
Rott, N. 1956 Diffraction of a weak shock with vortex generation. J. Fluid Mech. 1, 111128.Google Scholar
Shelley, M. 1992 A study of singularity formation in vortex-sheet motion by a spectrally accurate vortex method. J. Fluid Mech. 244, 493526.Google Scholar
Supplementary material: PDF

Ishihara and Kaneda supplementary material

Appendices

Download Ishihara and Kaneda supplementary material(PDF)
PDF 2.1 MB