Direct numerical simulation of wall-bounded magnetohydrodynamic turbulent flows at moderate Reynolds and Hartmann numbers.

Wall-bounded (WB) magnetohydrodynamic (MHD) turbulence is crucial in various technological fields, especially in fusion energy sciences. However, our understanding of WBMHD turbulence still lags behind its non-magnetic counterpart. In this study, we conduct direct numerical simulations (DNS) of WBMHD turbulence at moderate Reynolds (Re) and Hartmann (Ha) numbers to understand the nature of WBMHD turbulence. We use the pseudo-spectral method in streamwise and spanwise directions and the high-order basis spline method in the wall-normal direction. We impose a constant magnetic field in the wall-normal direction for simplicity with low magnetic Re assumptions. Ha ranges from 1 to 100, while Re reaches up to 40000, equivalent to a friction Re of 1000 without magnetic fields. Preliminary results show that the mean-velocity profile of Re = 40000 flows is significantly influenced when Ha is greater than 10, and this influence starts from the outer flows. Additionally, we analyze the impact of the magnetic field on the turbulent kinetic energy (TKE) through the terms in the TKE budget equations. Our presentation emphasizes the key differences between WBMHD turbulence and canonical WB turbulence as a function of Re and Ha.