  Bulk velocities exceed thermal velocities for sufficiently radiation pressure
dominated accretion flows. We model the contribution of bulk Comptonization to
the soft X-ray excess in AGN. Bulk Comptonization is due to both turbulence and
the background shear. We calculate spectra both taking into account and not
taking into account bulk velocities using scaled data from radiation
magnetohydrodynamic (MHD) shearing box simulations. We characterize our results
with temperatures and optical depths to make contact with other warm
Comptonization models of the soft excess. We chose our fiducial mass, $M = 2
\times 10^6 M_{\odot}$, and accretion rate, $L/L_{\rm Edd} = 2.5$, to
correspond to those fit to the super-Eddington narrow line Seyfert 1 (NLS1)
RE1034+396. The temperatures, optical depths, and Compton $y$ parameters we
find broadly agree with those fit to RE1034+396. The effect of bulk
Comptonization is to shift the Wien tail to higher energy and lower the gas
temperature, broadening the spectrum. Observations of the soft excess in NLS1s
can constrain the properties of disc turbulence if the bulk Comptonization
contribution can be separated out from contributions from other physical
effects, such as reflection and absorption.
