EXPERIMENTAL STUDY OF TURBULENT DIAMAGNETISM IN A LIQUID SODIUM FLOW
DOI:
Keywords:
magnetohydrodynamics, turbulence, fluctuations, liquid sodium, mean magnetic field, diamagnetismAbstract
The phenomenon of magnetic field suppression by a turbulized flow of liquid sodium at medium Reynolds magnetic numbers Rm > 10 was experimentally studied. The magnetic field is applied collinearly to streamlines of a large-scale mean flow, which excludes the induction effects due to the average flow, as well as the contribution of turbulent diffusion. We show that at the stage of high turbulence, the mean magnetic field is reduced to 0.6 of the initial one. The observed effect can be explained as a result of turbulent diamagnetism, described by a term rot(g×B) of the mean-field induction equation (here g is the gradient of the energy of turbulent fluctuations and B is the mean magnetic field).
References
- Raedler K.-H., Stepanov R. Mean electromotive force due to turbulence of a conducting fluid in the presence of mean flow // Phys. Rev. E. - 2006. - Vol. 73. - P. 056311.
- Frick P., Noskov V., Denisov S., Stepanov R. Direct Measurement of Effective Magnetic Diffusivity in Turbulent Flow of Liquid Sodium // Phys. Rev. Lett. - 2010. - Vol. 105. - No 18. - R. 184502.
- Noskov V. [et al.] Dynamics of a turbulent spin-down flow inside a torus // Phys. Fluids. - 2009. - Vol. 21. - No 4. - R. 045108.
- Frick P., Noskov V., Denisov S., Stepanov R. Turbulent viscosity and turbulent magnetic diffusivity in a decaying spin-down flow of liquid sodium // Phys. Rev. E. - 2012. - Vol. 85. - No 1. - R. 016303.