Two-dimensional Poynting flux dominated flow onto a Schwarzschild black hole

We discuss the dynamics of the accretion flow onto a black hole driven by Poynting flux in a simplified model of a two-dimensional accretion disk. In this simplified model, the condition of the stationary accretion flow is found to impose a nontrivial constraint on the magnetic field configuration. The effect of the magnetic field on the accretion flow is discussed in detail using the paraboloidal- and hyperboloidal-type configurations for the poloidal structure suggested by Blandford in 1976. It is demonstrated explicitly that the angular velocity of the disk Omega(D) deviates from the Keplerian angular velocity. The angular velocity of the rigidly rotating magnetic surface Omega(F) does not have to be the same as the angular velocity of the disk for the paraboloidal-type configuration. But for the hyperboloidal type configuration, it is found that we can set Omega(F)=Omega(D), which corresponds to an accretion disk of perfect conductor. We discuss the numerical solutions of the stream equation for stationary accretion flow in the Schwarzschild background using a paraboloidal-type configuration. The dynamics of the accretion disk is found to depend strongly on the ratio of the accretion rate to the magnetic field strength.