  The accretion of hydrogen-rich material onto carbon-oxygen white dwarfs (CO
WDs) is crucial for understanding type Ia supernova (SN Ia) from the
single-degenerate model, but this process has not been well understood due to
the numerical difficulties in treating H and He flashes during the accretion.
For the CO WD masses from 0.5 to $1.378\,{M}_\odot$ and accretion rates in the
range from $10^{-8}$ to $10^{-5}\,{M}_\odot\,\mbox{yr}^{-1}$, we simulated the
accretion of solar-composition material onto CO WDs using the state-of-the-art
stellar evolution code of {\sc MESA}. For comparison with the steady-state
models (e.g \citet{nskh07}), we firstly ignored the contribution from nuclear
burning to the luminosity when determining the Eddington accretion rate and
found that the properties of H burning in our accreting CO WD models are
similar to those from the steady-state models, except that the critical
accretion rates at which the WDs turn into red giants or H-shell flashes occur
on their surfaces are slightly higher than those from the steady-state models.
However, the super-Eddington wind is triggered at much lower accretion rates,
than previously thought, when the contribution of nuclear burning to the total
luminosity is included. This super-Eddington wind naturally prevents the CO WDs
with high accretion rates from becoming red giants, thus presenting an
alternative to the optically thick wind proposed by \cite{hkn96}. Furthermore,
the super-Eddington wind works in low-metallicity environments, which may
explain SNe Ia observed at high redshifts.
