  A stellar mass black hole (BH) surrounded by a neutrino-dominated accretion
flow (NDAF) has been discussed in a number of works as the central engine of
gamma-ray bursts (GRBs). It is widely believed that NDAF cannot liberate enough
energy for bright GRBs. However, these works have been based on the assumption
of "no torque" boundary condition, which is invalid when the disk is
magnetized. In this paper, we present both numerical and analytical solutions
for NDAFs with non-zero boundary stresses, and reexamine their properties. We
find that NDAF with such boundary torque can be powerful enough to account for
those bright short GRBs, energetic long GRBs and ultra-long GRBs. The disk
becomes viscously unstable, which makes it possible to interpret the
variability of GRB prompt emission and the steep decay phase in the early X-ray
afterglow. Finally, we study the gravitational waves radiated from a processing
BH-NDAF. We find that the effects of the boundary torque on the strength of the
gravitational waves can be ignored.
