Exact Coherent States and Phase Space Geometry of Channel Flow with Streamwise Magnetic Field

In this study, we explore the behavior of exact coherent states (ECS) in magnetohydrodynamic (MHD) channel flow with Reynolds numbers ranging from Re = 3000 to Re = 5000. Our investigation focuses on the identifying of exact coherent structures and connecting orbits in the presence of a constant, uniform magnetic field oriented along the streamwise direction. High-resolution direct numerical simulations (DNS) are employed to examine the ECS in a computational domain of 2π(x) × 2.4(y) × 2(z). Bisection method were utilized on initial perturbations to identify the ECS. Our findings reveal that the presence of a streamwise magnetic field results in the elongation of exact coherent structures in the streamwise direction. As the magnetic field strength increases, the streaks and flow vortex are intensified, leading to a dissimilar root mean square velocity distribution.