  We explore the detectability of bulk motions in the X-ray emitting
intracluster medium (ICM) using a catalog of 1,836 mock Astro-E2 observations
of simulated clusters of galaxies. We generate high resolution mock spectra for
two observing strategies: a four-pointing mosaic and a single central pointing.
Normalizing to 200 (400) photons in the iron K-alpha region for the mosaic
(central) study, we fit Poisson realizations of each simulated spectrum to a
velocity broadened isothermal plasma emission model. We confirm that the
velocity characteristics (mean and dispersion) returned by the spectral
fittings are unbiased measures of the emission-weighted values within the
observed region, with scatter 55 km/s. The maximum velocity difference between
mosaic element pairs $\Delta v_{\rm max}$ has ~ 6% likelihood of being
transonic ($\Delta v_{\rm max} \ge 0.5 c_s$), and the likelihood falls steeply,
$p \spropto (\Delta v_{\rm max}/c_s)^{-4}$, at high Mach number. The velocity
broadening parameter $\sigma_v$ from the central pointing fit exceeds the
thermal value in 49% of the cases, with again a $\sigma_v^{-4}$ tail at large
dispersion. We present as case studies the clusters that yield the strongest
signal for each observing strategy.
