The velocity field induced by a helical vortex tube

The influence of finite-core thickness on the velocity field around a vortex tube is addressed. An asymptotic expansion of the Biot-Savart law is made to a higher order in a small parameter, the ratio of core radius to curvature radius, which consists of the velocity field due to lines of monopoles and dipoles arranged on the centerline of the tube. The former is associated with an infinitely thin core and is featured by the circulation alone. The distribution of vorticity in the core reflects on the strength of dipole. This result is applied to a helical vortex tube, and the induced velocity due to a helical filament of the dipoles is obtained in the form of the Kapteyn series, which augments Hardin’s [Phys. Fluids 25, 1949 (1982)] solution for the monopoles. Using a singularity-separation technique, a substantial part of the series is represented in a closed form for both the mono- and the dipoles. It is found from numerical calculation that the smaller the helix pitch is, the larger the relative influe...

[1]  Y. Fukumoto Higher-order asymptotic theory for the velocity field induced by an inviscid vortex ring , 2002 .

[2]  S. Widnall The stability of a helical vortex filament , 1972, Journal of Fluid Mechanics.

[3]  S. Leibovich Vortex stability and breakdown - Survey and extension , 1984 .

[4]  S. V. Alekseenko,et al.  Helical vortices in swirl flow , 1999, Journal of Fluid Mechanics.

[5]  Y. Fukumoto,et al.  Curvature instability of a vortex ring , 2005, Journal of Fluid Mechanics.

[6]  Donald B. Bliss,et al.  Theoretical and Experimental Study of the Stability of a Vortex Pair , 1971 .

[7]  C. Tung,et al.  Motion and Decay of a Vortex Ring , 1967 .

[8]  H. Levy,et al.  The Steady Motion and Stability of a Helical Vortex , 1928 .

[9]  Marcel Escudier,et al.  Vortex breakdown: Observations and explanations , 1988 .

[10]  J. Boersma,et al.  On the motion of multiple helical vortices , 2001, Journal of Fluid Mechanics.

[11]  Y. Fukumoto,et al.  Short-wavelength stability analysis of thin vortex rings , 2003 .

[12]  D. Dritschel Generalized helical Beltrami flows in hydrodynamics and magnetohydrodynamics , 1991, Journal of Fluid Mechanics.

[13]  Milton Rogers,et al.  AIRCRAFT WAKE TURBULENCE AND ITS DETECTION , 1971 .

[14]  A. Callegari,et al.  Motion of a curved vortex filament with decaying vortical core and axial velocity , 1978 .

[15]  A. Leonard NONLOCAL THEORY OF AREA-VARYING WAVES ON AXISYMMETRIC VORTEX TUBES , 1994 .

[16]  Y. Fukumoto Three-dimensional motion of a vortex filament and its relation to the localized induction hierarchy , 2002 .

[17]  J. Hardin The velocity field induced by a helical vortex filament , 1982 .

[18]  H. K. Moffatt,et al.  Motion and expansion of a viscous vortex ring. Part 1. A higher-order asymptotic formula for the velocity , 2000, Journal of Fluid Mechanics.

[19]  Tullio Levi-Civita,et al.  Attrazione newtoniana dei tubi sottili e vortici filiformi , 1932 .

[20]  Y. Fukumoto,et al.  Three-dimensional distortions of a vortex filament with axial velocity , 1991, Journal of Fluid Mechanics.

[21]  瀬片 純市 Well-posedness for the Fourth Order Nonlinear Schrodinger Type Equation Related to the Vortex Filament (流体と気体の数学解析 研究集会報告集) , 2003 .

[22]  Self-stretching of a perturbed vortex filament I: the asymptotic equation for deviations from a straight line , 1991 .

[23]  Renzo L. Ricca,et al.  The contributions of Da Rios and Levi-Civita to asymptotic potential theory and vortex filament dynamics , 1996 .

[24]  M. Landman On the generation of helical waves in circular pipe flow , 1990 .

[25]  G. Watson Bessel Functions. (Scientific Books: A Treatise on the Theory of Bessel Functions) , 1923 .

[26]  Thomas S. Lundgren,et al.  Area-varying waves on curved vortex tubes with application to vortex breakdown , 1989, Journal of Fluid Mechanics.

[27]  J. Boersma,et al.  On the self-induced motion of a helical vortex , 1999, Journal of Fluid Mechanics.

[28]  T. Maxworthy,et al.  Three-dimensional vortex breakdown in swirling jets and wakes: direct numerical simulation , 2003, Journal of Fluid Mechanics.

[29]  Renzo L. Ricca,et al.  The effect of torsion on the motion of a helical vortex filament , 1994, Journal of Fluid Mechanics.

[30]  P. Kuibin,et al.  Self-induced motion and asymptotic expansion of the velocity field in the vicinity of a helical vortex filament , 1998 .

[31]  ON THE EXISTENCE OF STEADY HELICAL VORTEX TUBES OF SMALL CROSS-SECTION , 1981 .

[32]  V. Okulov On the stability of multiple helical vortices , 2004, Journal of Fluid Mechanics.

[33]  D. W. Moore,et al.  The motion of a vortex filament with axial flow , 1972, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[34]  L. E. Fraenkel,et al.  Examples of steady vortex rings of small cross-section in an ideal fluid , 1972, Journal of Fluid Mechanics.

[35]  Irene A. Stegun,et al.  Handbook of Mathematical Functions. , 1966 .

[36]  F. Dyson,et al.  The Potential of an Anchor Ring. Part II , 1893 .

[37]  P. Saffman,et al.  The Velocity of Viscous Vortex Rings , 1970 .

[38]  G. A. Watson A treatise on the theory of Bessel functions , 1944 .

[39]  S. Crow Stability theory for a pair of trailing vortices , 1970 .