Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-21T02:04:37.918Z Has data issue: false hasContentIssue false

The free compressible viscous vortex

Published online by Cambridge University Press:  26 April 2006

Tim Colonius
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Sanjiva K. Lele
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Parviz Moin
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA

Abstract

The effects of compressibility on free (unsteady) viscous heat-conducting vortices are investigated. Analytical solutions are found in the limit of large, but finite, Reynolds number, and small, but finite, Mach number. The analysis shows that the spreading of the vortex causes a radial flow. This flow is given by the solution of an ordinary differential equation (valid for any Mach number), which gives the dependence of the radial velocity on the tangential velocity, density, and temperature profiles of the vortex; estimates of the radial velocity found by solving this equation are found to be in good agreement with numerical solutions of the full equations. The experiments of Mandella (1987) also report a radial flow in the vortex, but their estimates are much larger than the analytical predictions, and it is found that the flow inferred from the iexperiments violates the Second Law of Thermodynamics for two-dimensional axisymmetric flow. It is speculated that three-dimensionality is the cause of this discrepancy. To obtain detailed analytical solutions, the equations for the viscous evolution are expanded in powers of Mach number, M. Solutions valid to O(M2), are discussed for vortices with finite circulation. Two specific initial conditions – vortices with initially uniform entropy and with initially uniform density – are analysed in detail. It is shown that swirling axisymmetric compressible flows generate negative radial velocities far from the vortex core owing to viscous effects, regardless of the initial distributions of vorticity, density and entropy.

Type
Research Article
Copyright
© 1991 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

Abramowitz, M. A. & Stegun, I. A. 1972 Handbook of Mathematical Functions. Dover.
Bellamy-Knights, P. G. 1980 Viscous compressible heat conducting spiraling flow. Q. J. Mech. Appl. Maths 33, 321336.Google Scholar
Bershader, D. 1988 Shock tube studies of vortex structure and behavior. Shock Tubes and Waves: Proc. Sixteenth Intl Symp. on Shock Tubes and Waves, pp. 518. VCH Verlagsgesellschaft.
Colonius, T., Lele, S. K. & Moin, P. 1991 Scattering of sound waves by a compressible vortex. AIAA Paper 91–0494.Google Scholar
Incropera, F. P. & Dewitt, D. P. 1985 Introduction to Heat Transfer. John Wiley & Sons.
Lele, S. K. 1990 Compact finite difference schemes with spectral-like resolution. CTR Manuscript 107. Stanford University; J. Comput. Phys. (submitted).Google Scholar
Long, R. R. 1961 A vortex in an infinite viscous fluid. J. Fluid Mech. 11, 611624.Google Scholar
Mack, L. M. 1960 The compressible viscous heat-conducting vortex. J. Fluid Mech. 8, 284292.Google Scholar
Mandella, M. J. 1987 Experimental and analytical studies of compressible vortices. Ph.D. thesis, Stanford University.
Mandella, M., Moon, Y. J. & Bershadeb, D. 1986 Quantitative study of shock generated compressible vortex flows. In Shock Waves and Shock Tubes (ed. D. Bershader & R. Hanson), pp. 471477. Stanford University Press.
Merzkirch, W. 1964 Theoretische und experimentelle Untersuchungen an einer instationaUren WirbelstroUmung. Z. Flugwiss 12, 395401.Google Scholar
Morton, B. R. 1969 The strength of vortex and swirling core flows. J. Fluid Mech. 38, 315333.Google Scholar
Neufville, A. De 1957 The dying vortex. In Prof. Fifth Midwestern Conf. on Fluid Mechanics, p. 365. University of Michigan.
Oseen, C. W. 1912 Über Wirbelbewegung in einer reibenden FluUssigkeit. Ark.f. Mat. Astron. Fys. 7, 14.Google Scholar
Rott, N. 1959 On the viscous core of a line vortex II. Z. Angew. Math. Phys. 10, 7381.Google Scholar
Rott, N. & Lewellen, W. S. 1966 Boundary layers and their interactions in rotating flows. Prog. Aeronaut. Sci. 7, 111144.Google Scholar
Sibulkin, M. 1961 Unsteady, viscous, circular flow. Part 1. The line impulse of angular momentum. J.Fluid Mech. 11, 291308.Google Scholar
Taylor, G. I. 1918 On the dissipation of eddies. Aero. Res. Comm., R and M 598.Google Scholar
Taylor, G. I. 1930 Recent work on the flow of compressible fluids. J. Lond. Math. Soc. 5, 224240.Google Scholar
Thompson, K. W. 1987 Time dependent boundary conditions for hyperbolic systems. J. Comput. Phys. 68, 124.Google Scholar
Uberoi, M. S. 1979 Mechanisms of decay of laminar and turbulent vortices. J. Fluid Mech. 90, 241255.Google Scholar