  A numerical study of the dynamic of the nonselfgravitating, unmagnetized,
nonaxisymmetric, and rotating the torus around the non-rotating black hole is
presented. We investigate the instability of the rotating torus subject to
perturbations presented by increasing or decreasing the angular velocity of the
stable torus. We have done, for the first time, an extensive analysis of the
torus dynamic response to the perturbation of the angular velocity of the
stable torus. We show how the high, moderate, and low values of the
perturbations affect the torus dynamic and help us to understand the properties
of the instability and Quasi-Periodic Oscillation (QPO). Our numerical
simulations indicate the presence of Papaloizou-Pringle instability (PPI) with
global m=1 mode and QPOs for the moderate and lower values of the perturbations
on the angular velocity of the stable torus. Furthermore, with the lower values
of the perturbations, the torus can lead to a wiggling initially and then PPI
is produced in it. Finally, the matter of the torus would be dissipated due to
the presence of a strong torque.
