  Coronal magnetic flux ropes are generally considered to be the core structure
of large-scale solar eruptions. Recent observations found that solar eruptions
could be initiated by a sequence of "flux feeding," during which chromospheric
fibrils rise upward from below, and merge with a pre-existing prominence.
Further theoretical study has confirmed that the flux feeding mechanism is
efficient in causing the eruption of flux ropes that are wrapped by bald patch
separatrix surfaces. But it is unclear how flux feeding influences coronal flux
ropes that are wrapped by hyperbolic flux tubes (HFT), and whether it is able
to cause the flux-rope eruption. In this paper, we use a 2.5-dimensional
magnetohydrodynamic model to simulate the flux feeding processes in HFT
configurations. It is found that flux feeding injects axial magnetic flux into
the flux rope, whereas the poloidal flux of the rope is reduced after flux
feeding. Flux feeding is able to cause the flux rope to erupt, provided that
the injected axial flux is large enough so that the critical axial flux of the
rope is reached. Otherwise, the flux rope system evolves to a stable
equilibrium state after flux feeding, which might be even farther away from the
onset of the eruption, indicating that flux feeding could stabilize the rope
system with the HFT configuration in this circumstance.
