Numerical simulation of turbulent flow in FlowCube platform under a strong magnetic field

The investigation of magnetohydrodynamic (MHD) flow has been carried out through a two-dimensional approximation known as the PSM model within the FlowCube platform (Pothérat and Klein, 2014). The platform itself is a cubic vessel featuring alternating positive and negative electrodes that are uniformly located on its bottom. The flow is driven by the Lorentz force, which is induced by injected currents and imposed magnetic fields. The energy spectrum of two-dimensional flow agrees well with our three-dimensional one, confirming the two-dimensionality of MHD turbulence under strong magnetic fields. For quasi-two-dimensional (Q2D) flow in FlowCube, the energy spectrum displays ∼ k ⁻³ and ∼ k ² slopes, corresponding to direct enstrophy cascade from forcing scale l_i to small scale and statistical equilibrium state of large scale (> l_i), where l_i is electrodes space in FlowCube. Moreover, a comprehensive study has been conducted on the transition from a laminar state to a turbulent state, revealing various flow states, including periodic, quasi-periodic, and chaotic states. Furthermore, under the same driving force, the periodic network of alternating vortices, which are typical structures in the FlowCube configuration, display different flow states. This observation may correspond to a large-scale intermittency in MHD flows due to the complex interaction between the driving force and dissipation.[Figure not available: see fulltext.]