Effect of Shear Flow on the Double Tearing Mode Induced by Resonant Magnetic Perturbation

Based on the two-dimensional resistive magnetohydrodynamics (MHD) model, this study explores the impact of shear flow on the resonant magnetic perturbation (RMP)-induced double tearing mode (DTM). The results indicate that the effectiveness of shear flow in suppressing the double tearing mode is primarily dependent on the flow velocity at the outer rational surface. A notable finding is that, with higher flow velocities, the double tearing mode is effectively suppressed. However, in cases of very weak flow velocities, the shear flow still exerts an influence, but with a limited suppression effect. Specifically, it can only inhibit the inner island, while the outer island continues to grow under the influence of the resonant magnetic perturbation.