  We present the results of numerical simulations of continuum-driven winds of
stars that exceed the Eddington limit and compare these against predictions
from earlier analytical solutions. Our models are based on the assumption that
the stellar atmosphere consists of clumped matter, where the individual clumps
have a much larger optical thickness than the matter between the clumps. This
`porosity' of the stellar atmosphere reduces the coupling between radiation and
matter, since photons tend to escape through the more tenuous gas between the
clumps. This allows a star that formally exceeds the Eddington limit to remain
stable, yet produce a steady outflow from the region where the clumps become
optically thin. We have made a parameter study of wind models for a variety of
input conditions in order to explore the properties of continuum-driven winds.
  The results show that the numerical simulations reproduce quite closely the
analytical scalings. The mass loss rates produced in our models are much larger
than can be achieved by line driving. This makes continuum driving a good
mechanism to explain the large mass loss and flow speeds of giant outbursts, as
observed in eta Carinae and other luminous blue variable (LBV) stars. Continuum
driving may also be important in population III stars, since line driving
becomes ineffective at low metalicities. We also explore the effect of photon
tiring and the limits it places on the wind parameters.
