  We present numerical simulations of misaligned discs around a spinning black
hole covering a range of parameters. Previous simulations have shown that discs
that are strongly warped by a forced precession -- in this case the
Lense-Thirring effect from the spinning black hole -- can break apart into
discrete discs or rings that can behave quasi-independently for short
timescales. With the simulations we present here, we confirm that thin and
highly inclined discs are more susceptible to disc tearing than thicker or low
inclination discs, and we show that lower values of the disc viscosity
parameter lead to instability at lower warp amplitudes. This is consistent with
detailed stability analysis of the warped disc equations. We find that the
growth rates of the instability seen in the numerical simulations are similar
across a broad range of parameters, and are of the same order as the predicted
growth rates. However, we did not find the expected trend of growth rates with
viscosity parameter. This may indicate that the growth rates are affected by
numerical resolution, or that the wavelength of the fastest growing mode is a
function of local disc parameters. Finally, we also find that disc tearing can
occur for discs with a viscosity parameter that is higher than predicted by a
local stability analysis of the warped disc equations. In this case, the
instability manifests differently producing large changes in the disc tilt
locally in the disc, rather than the large changes in disc twist that typically
occur in lower viscosity discs.
