Magnetohydrodynamic (MHD) investigations of decaying isotropic turbulenceand rectangular jets (RJ) are carried out. A novel MHD lattice Boltzmann scheme thatcombines multiple relaxation time (MRT) parameters for the velocity field with a singlerelaxation time (SRT) parameter for the Maxwell?s stress tensor is developed for thisstudy.In the MHD homogeneous turbulence studies, the kinetic/magnetic energy andenstrophy decays, kinetic enstrophy evolution, and vorticity alignment with the strain-ratetensor are evaluated to assess the key physical MHD turbulence mechanisms. Themagnetic and kinetic energies interact and exchange through the influence of the Lorentzforce work. An initial random fluctuating magnetic field increases the vortex stretchingand forward cascade mechanisms. A strong uniform mean magnetic field increases theanisotropy of the turbulent flow field and causes inverse cascading.In the RJ studies, an investigation into the MHD effects on velocity, instability,and the axis-switching phenomena is performed at various magnetic field strengths andMagnetic Reynolds Numbers. The magnetic field is found to decelerate the jet core,inhibit instability, and prevent axis-switching. The key physical mechanisms are: (i) theexchange of energy between kinetic and magnetic modes and (ii) the magnetic fieldeffect on the vorticity evolution.From these studies, it is found that magnetic field influences momentum, vorticity,and energy evolution and the degree of modification depends on the field strength. Thisinteraction changes vortex evolution, and alters turbulence processes and rectangular jetflow characteristics. Overall, this study provides more insight into the physics of MHDflows, which suggests possible applications of MHD Flow Control.
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