  Misaligned accretion disks surrounding rotating compact objects experience a
torque due to the Lense-Thirring effect, which leads to precession of the inner
disk. It has been suggested that this effect could be responsible for some low
frequency Quasi-Periodic Oscillations observed in the X-ray lightcurves of
neutron star and galactic black hole systems. We investigate this possibility
via time-dependent calculations of the response of the inner disk to impulsive
perturbations for both Newtonian point mass and Paczynski-Wiita potentials, and
compare the results to the predictions of the linearized twisted accretion disk
equations. For most of a wide range of disk models that we have considered, the
combination of differential precession and viscosity causes the warps to decay
extremely rapidly. Moreover, at least for relatively slowly rotating objects,
linear calculations in a Newtonian point mass potential provide a good measure
of the damping rate, provided only that the timescale for precession is much
shorter than the viscous time in the inner disk. The typically rapid decay
rates suggest that coherent precession of a fluid disk would not be observable,
though it remains possible that the damping rate of warp in the disk could be
low enough to permit weakly coherent signals from Lense-Thirring precession.
