Magnetic helicity generation in the frame of Kazantsev model |
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| Authors: | Egor V Yushkov Alexander S Lukin |
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| Institution: | 1. Faculty of Physics, Department of Mathematics, Lomonosov University, Moscow, Russia.;2. Space Research Institute RAS (IKI), Moscow, Russia.;3. National Research University Higher School of Economics, Moscow, Russia. |
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| Abstract: | Using a magnetic dynamo model, suggested by Kazantsev (J. Exp. Theor. Phys. 1968, vol. 26, p. 1031), we study the small-scale helicity generation in a turbulent electrically conducting fluid. We obtain the asymptotic dependencies of dynamo growth rate and magnetic correlation functions on magnetic Reynolds numbers. Special attention is devoted to the comparison of a longitudinal correlation function and a function of magnetic helicity for various conditions of asymmetric turbulent flows. We compare the analytical solutions on small scales with numerical results, calculated by an iterative algorithm on non-uniform grids. We show that the exponential growth of current helicity is simultaneous with the magnetic energy for Reynolds numbers larger than some critical value and estimate this value for various types of asymmetry. |
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| Keywords: | Small-scale dynamo Kazantsev model asymptotic and numerical analysis large magnetic Reynolds number |
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