Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-24T23:03:05.109Z Has data issue: false hasContentIssue false

Shear-driven Hall-magnetohydrodynamic dynamos

Published online by Cambridge University Press:  15 December 2021

Kengo Deguchi*
Affiliation:
School of Mathematics, Monash University, VIC 3800, Australia
*
Email address for correspondence: [email protected]

Abstract

Nonlinear Hall-magnetohydrodynamic dynamos associated with coherent structures in subcritical shear flows are investigated by using unstable invariant solutions. The dynamo solution found has a relatively simple structure, but it captures the features of the typical nonlinear structures seen in simulations, such as current sheets. As is well known, the Hall effect destroys the symmetry of the magnetohydrodynamic equations and thus modifies the structure of the current sheet and mean field of the solution. Depending on the strength of the Hall effect, the generation of the magnetic field changes in a complex manner. However, a too strong Hall effect always acts to suppress the magnetic field generation. The hydrodynamic/magnetic Reynolds number dependence of the critical ion skin depth at which the dynamos start to feel the Hall effect is of interest from an astrophysical point of view. An important consequence of the matched asymptotic expansion analysis of the solution is that the higher the Reynolds number, the smaller the Hall current affects the flow. We also briefly discuss how the above results for a relatively simple shear flow can be extended to more general flows such as infinite homogeneous shear flows and boundary layer flows. The analysis of the latter flows suggests that interestingly a strong induction of the generated magnetic field might occur when there is a background shear layer.

Type
JFM Papers
Copyright
© The Author(s), 2021. Published by 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

REFERENCES

Béthune, W., Lesur, G. & Ferreira, J. 2017 Global simulations of protoplanetary disks with net magnetic flux. Astron. Astrophys. 600, A75.CrossRefGoogle Scholar
Bai, X. 2015 Hall effect controlled gas dynamics in protoplanetary disks. II. Full 3D simulations toward the outer disk. Astrophys. J. 798, 84.CrossRefGoogle Scholar
Balbus, S.A. & Terquem, C. 2001 Linear analysis of the Hall effect in protostellar disks. Astrophys. J. 552, 235247.CrossRefGoogle Scholar
Blackburn, H.M., Deguchi, K. & Hall, P. 2021 Distributed vortex-wave interactions: the relation of self-similarity to the attached eddy hypothesis. J. Fluid Mech. 924, A8.CrossRefGoogle Scholar
Blackburn, H.M., Hall, P. & Sherwin, S. 2013 Lower branch equilibria in Couette flow: the emergence of canonical states for arbitrary shear flows. J. Fluid Mech. 726, R2.CrossRefGoogle Scholar
Bora, K., Bhattacharyya, R. & Smolarkiewicz, P.K. 2021 Evolution of three-dimensional coherent structures in Hall magnetohydrodynamics. Astrophys. J. 906, 102.CrossRefGoogle Scholar
Brandenburg, A., Nordlund, A., Stein, R.F. & Torkelsson, U. 1995 Dynamo-generated turbulence and large-scale magnetic fields in a Keplerian shear flow. Astrophys. J. 446, 741.CrossRefGoogle Scholar
Cally, P. & Khomenko, E. 2015 Fast-to-Alfvén mode conversion mediated by the hall current. I. Cold plasma model. Astrophys. J. 814, 106.CrossRefGoogle Scholar
Carbone, V. 2012 Scalings, cascade and intermittency in solar wind turbulence. Space Sci. Rev. 172, 343360.CrossRefGoogle Scholar
Charbonneau, P. 2014 Solar dynamo theory. Annu. Rev. Astron. Astrophys. 94, 3948.Google Scholar
Charbonneau, P, Tomczyk, S., Schou, J. & Thompson, M.J. 1998 The rotation of the solar core inferred by genetic forward modeling. Astrophys. J. 496, 10151030.CrossRefGoogle Scholar
Clever, R.M. & Busse, F.H. 1992 Three-dimensional convection in a horizontal fluid layer subjected to a constant shear. J. Fluid Mech. 234, 511527.CrossRefGoogle Scholar
Deguchi, K. 2015 Self-sustained states at Kolmogorov microscale. J. Fluid Mech. 781, R6.CrossRefGoogle Scholar
Deguchi, K. 2017 Scaling of small vortices in stably stratified shear flows. J. Fluid Mech. 821, 582594.CrossRefGoogle Scholar
Deguchi, K. 2019 a High-speed shear driven dynamos. Part 1. Asymptotic analysis. J. Fluid Mech. 868, 176211.CrossRefGoogle Scholar
Deguchi, K. 2019 b High-speed shear-driven dynamos. Part 2. Numerical analysis. J. Fluid Mech. 876, 830858.CrossRefGoogle Scholar
Deguchi, K. 2020 a Streaky dynamo equilibria persisting at infinite Reynolds numbers. J. Fluid Mech. 884, R3.CrossRefGoogle Scholar
Deguchi, K. 2020 b Subcritical magnetohydrodynamic instabilities: Chandrasekhar's theorem revisited. J. Fluid Mech. 882, A20.CrossRefGoogle Scholar
Deguchi, K. & Hall, P. 2014 a The high Reynolds number asymptotic development of nonlinear equilibrium states in plane Couette flow. J. Fluid Mech. 750, 99112.CrossRefGoogle Scholar
Deguchi, K. & Hall, P. 2014 b Free-stream coherent structures in parallel boundary-layer flows. J. Fluid Mech. 752, 602625.CrossRefGoogle Scholar
Deguchi, K. & Hall, P. 2015 Free-stream coherent structures in growing boundary layers: a link to near-wall streaks. J. Fluid Mech. 778, 451484.CrossRefGoogle Scholar
Deguchi, K. & Hall, P. 2017 The relationship between free-stream coherent structures and near-wall streaks at high Reynolds numbers. Phil. Trans. R. Soc. Lond. A 375, 20160078.Google ScholarPubMed
Deguchi, K. & Hall, P. 2018 Free-stream coherent structures in a planar jet. J. Fluid Mech. 837, 916930.CrossRefGoogle Scholar
Dempsey, L.J., Deguchi, K., Hall, P. & Walton, A.G. 2016 Localized vortex/Tollmien-Schlichting wave interaction states in plane Poiseuille flow. J. Fluid Mech. 791, 97121.CrossRefGoogle Scholar
Duck, P.W., Ruban, A.I. & Zhikharev, C.N. 1996 The generation of Tollmien-Schlichting waves by free-stream turbulence. J. Fluid Mech. 312, 341371.CrossRefGoogle Scholar
Flanagan, K., Milhone, J., Egedal, J., Endrizzi, D., Olson, J., Peterson, E.E., Sassella, R. & Forest, C.B. 2020 Weakly magnetized, Hall dominated plasma Couette flow. Phys. Rev. Lett. 125, 135001.CrossRefGoogle ScholarPubMed
Gómez, D.O., Mininni, P.D. & Dmitruk, P. 2010 Hall-magnetohydrodynamic small-scale dynamos. Phys. Rev. E 82, 036406.CrossRefGoogle ScholarPubMed
Gerz, T., Schumann, U. & Elgobashi, S.E. 1989 Direct numerical simulation of stratified homogeneous shear flows. J. Fluid Mech. 200, 563594.CrossRefGoogle Scholar
Gibson, J.F., Halcrow, J. & Cvitanovic, P. 2008 Visualizing the geometry of state space in plane Couette flow. J. Fluid Mech. 611, 107130.CrossRefGoogle Scholar
Goldreich, P. & Reisenegger, A. 1992 Magnetic field decay in isolated neutron stars. Astrophys. J. 395, 250258.CrossRefGoogle Scholar
Goossens, M., Ruderman, M.S. & Hollweg, J.V. 1995 Dissipative MHD solutions for resonant Alfvén waves in 1-dimensional magnetic flux tubes. Sol. Phys. 157, 75102.CrossRefGoogle Scholar
Gourgouliatos, K.N., Hollerbach, R. & Archibald, R.F. 2018 Modelling neutron star magnetic fields. Astron. Geophys. 59, 5.375.42.CrossRefGoogle Scholar
Hall, P. 2018 Vortex-wave interaction arrays: a sustaining mechanism for the log layer? J. Fluid Mech. 850, 4682.CrossRefGoogle Scholar
Hall, P. & Sherwin, S. 2010 Streamwise vortices in shear flows: harbingers of transition and the skeleton of coherent structures. J. Fluid Mech. 661, 178205.CrossRefGoogle Scholar
Hall, P. & Smith, F.T. 1991 On strongly nonlinear vortex/wave interactions in boundary-layer transition. J. Fluid Mech. 227, 641666.CrossRefGoogle Scholar
Hameiri, E. & Ishizawa, A. 2005 Waves in the Hall-magnetohydrodynamics model. Phys. Plasmas 12, 072109.CrossRefGoogle Scholar
Hawley, J.F., Gammie, C.F. & Balbus, S.A. 1995 Local three-dimensional magnetohydrodynamic simulations of accretion disks. Astrophys. J. 440, 792.CrossRefGoogle Scholar
Helmis, G. 1971 Hall effect in the electrodynamics of conducting media in turbulent motion. Beitr. Plasmaphys. 11, 417430.CrossRefGoogle Scholar
Herreman, W. 2018 Minimal perturbation flows that trigger mean field dynamos in shear flows. J. Plasma Phys. 84, 735840305.CrossRefGoogle Scholar
Hof, B., van Doorne, C.W., Westerweel, J., Nieuwstadt, F.T., Faisst, H., Eckhardt, B., Wedin, H., Kerswell, R.R. & Waleffe, F. 2004 Experimental observation of nonlinear traveling waves in turbulent pipe flow. Science 305 (5690), 15941598.CrossRefGoogle ScholarPubMed
Hollerbach, R. & Rüdiger, G. 2002 The influence of Hall drift on the magnetic fields of neutron stars. Mon. Not. R. Astron. Soc. 337, 216224.CrossRefGoogle Scholar
Hori, D. & Miura, H. 2008 Spectrum properties of Hall MHD turbulence. Plasma Fusion Res. 3, S1053.CrossRefGoogle Scholar
Hori, K. & Yoshida, S. 2008 Non-local memory effects of the electromotive force by fluid motion with helicity and two-dimensional periodicity. Geophys. Astrophys. Fluid Dyn. 102 (6), 601632.CrossRefGoogle Scholar
Igoshev, A.P., Hollerbach, R., Wood, T. & & Gourgouliatos, K.N. 2021 Strong toroidal magnetic fields required by quiescent X-ray emission of magnetars. Nat. Astron. 5, 145149.CrossRefGoogle Scholar
Itano, T. & Toh, S. 2001 The dynamics of bursting process in wall turbulence. J. Phys. Soc. Japan 70, 703716.CrossRefGoogle Scholar
Kawahara, G., Uhlmann, M. & van Veen, L. 2012 The significance of simple invariant solutions in turbulent flows. Annu. Rev. Fluid Mech. 44, 203225.CrossRefGoogle Scholar
Kelly, M.C. 2009 The Earth's Ionosphere: Plasma Physics and Electrodynamics, 2nd ed. Academic Press (Elsevier).Google Scholar
Mahajan, S.M. & Yoshida, Z. 2000 A collisionless self-organizing model for the high-confinement (H-mode) boundary layer. Phys. Plasmas 7, 635640.CrossRefGoogle Scholar
Meyrand, R. & Galtier, S. 2012 Spontaneous chiral symmetry breaking of Hall magnetohydrodynamic turbulence. Phys. Rev. Lett. 109, 194501.CrossRefGoogle ScholarPubMed
Milhone, J., Flanagan, K., Egedal, J., Endrizzi, D., Olson, J., Peterson, E.E., Wright, J.C. & Forest, C.B. 2021 Ion heating and flow driven by an instability found in plasma Couette flow. Phys. Rev. Lett. 126, 185002.CrossRefGoogle ScholarPubMed
Mininni, P.D., Gómez, D.O. & Mahajan, S.M. 2003 Dynamo action in magnetohydrodynamics and Hall-magnetohydrodynamics. Astrophys. J. 587, 472481.CrossRefGoogle Scholar
Mininni, P.D., Gómez, D.O. & Mahajan, S.M. 2005 Direct simulations of helical Hall-MHD turbulence and dynamo action. Astrophys. J. 619, 10191027.CrossRefGoogle Scholar
Miura, H. & Araki, K. 2014 Structure transitions induced by the Hall term in homogeneous and isotropic magnetohydrodynamic turbulence. Phys. Plasmas 21, 072313.CrossRefGoogle Scholar
Nagata, M. 1990 Three-dimensional finite-amplitude solutions in plane Couette flow: bifurcation from infinity. J. Fluid Mech. 217, 519527.CrossRefGoogle Scholar
Nauman, F. & Blackman, E.G. 2017 Sustained turbulence and magnetic energy in nonrotating shear flows. Phys. Rev. E 95, 033202.CrossRefGoogle ScholarPubMed
Ossendrijver, M. 2003 The solar dynamo. Astron. Astrophys. Rev. 11, 287367.CrossRefGoogle Scholar
Rüdiger, G., Gellert, M., Hollerbach, R., Schultz, M. & Stefani, F. 2018 Stability and instability of hydromagnetic Taylor-Couette flows. Phys. Rep. 741, 189.CrossRefGoogle Scholar
Raboonik, A. & Cally, P.S. 2019 Hall-coupling of slow and Alfvén waves at low frequencies in the lower solar atmosphere. Solar Phys. 294, 147.CrossRefGoogle Scholar
Rincon, F. 2019 Dynamo theories. J. Plasma. Phys. 85, 205850401.CrossRefGoogle Scholar
Rincon, F., Ogilvie, G.I. & Proctor, M.R.E. 2007 Self-sustaining nonlinear dynamo process in Keplerian shear flows. Phys. Rev. Lett. 98, 254502.CrossRefGoogle ScholarPubMed
Riols, A., Rincon, F., Cossu, C., Lesur, G., Longaretti, P.-Y., Ogilvie, G.I. & Herault, J. 2013 Global bifurcations to subcritical magnetorotational dynamo action in Keplerian shear flow. J. Fluid Mech. 731, 145.CrossRefGoogle Scholar
Sakurai, T., Goossens, M. & Hollweg, J.V. 1991 Resonant behaviour of MHD waves on magnetic flux tubes. I. Connection formulae at the resonant surfaces. Sol. Phys. 133, 227245.CrossRefGoogle Scholar
Sano, T. & Stone, J.M. 2002 The effect of the Hall term on the nonlinear evolution of the magnetorotational instability. I. Local axisymmetric simulations. Astrophys. J. 570, 314328.CrossRefGoogle Scholar
Schumann, U. 1985 Algorithms for direct numerical simulation of shear-periodic turbulence. In Ninth Int. Conf. Num. Meth. Fluid Dyn. (ed. Soubbaramayer & J.P. Boujot), Lecture Notes in Physics, vol. 218, pp. 492–496.Google Scholar
Sekimoto, A. & Jiménez, J. 2017 Vertically localised equlibrium solutions in large-eddy simulations of homogeneous shear flow. J. Fluid Mech. 827, 225249.CrossRefGoogle Scholar
Shalybkov, D.A. & Urpin, V.A. 1997 The Hall effect and the decay of magnetic fields. Astron. Astrophys. 321, 685690.Google Scholar
Skufca, J.D., Yorke, J.A. & Eckhardt, B. 2006 Edge of chaos in a parallel shear flow. Phys. Rev. Lett. 96, 174101.CrossRefGoogle Scholar
Spangler, S.R. 2001 Multi-scale plasma turbulence in the diffuse interstellar medium. Space Sci. Rev. 99, 261270.CrossRefGoogle Scholar
Teed, R.J. & Proctor, M.R.E. 2017 Quasi-cyclic behaviour in non-linear simulations of the shear dynamo. Mon. Not. R. Astron. Soc. 467, 48584864.CrossRefGoogle Scholar
Tobias, S.M. 2021 The turbulent dynamo. J. Fluid Mech. 912, P1.CrossRefGoogle ScholarPubMed
Tobias, S.M. & Cattaneo, F. 2013 Shear-driven dynamo waves at high magnetic Reynolds number. Nature 497, 463465.CrossRefGoogle ScholarPubMed
Waleffe, F. 1997 On a self-sustaining process in shear flows. Phys. Fluids 9, 883900.CrossRefGoogle Scholar
Waleffe, F. 2001 Exact coherent structures in channel flow. J. Fluid Mech. 435, 93102.CrossRefGoogle Scholar
Wang, J., Gibson, J.F. & Waleffe, F. 2007 Lower branch coherent states: transition and control. Phys. Rev. Lett. 98, 204501.CrossRefGoogle ScholarPubMed
Yousef, T.A., Heinemann, T., Schekochihin, A.A., Kleeorin, N., Rogachevskii, I, Iskakov, A.B., Cowley, S.C. & McWilliams, J.C. 2008 Generation of magnetic field by combined action of turbulence and shear. Phys. Rev. Lett. 100, 184501.CrossRefGoogle ScholarPubMed