Hydrodynamics and global structure of rotating Schwarzschild black holes
  Exploiting a rotating Schwarzschild black hole metric, we study hydrodynamic properties of perfect fluid whirling inward toward the black holes along a conical surface. On the equatorial plane of the rotating Schwarzschild black hole, we derive radial equations of motion with effective potentials and the Euler equation for steady state axisymmetric fuid. Moreover, numerical analysis is performed to figure out effective potentials of particles on the rotating Schwarzschild manifolds in terms of angular velocity, total energy and angular momentum per unit rest mass. Higher dimensional global embeddings are also constructed inside and outside the event horizons of the rotating Schwarzschild black holes. 
Soon-Tae Hong and Sung-Won Kim