The Polish doughnuts revisited I. The angular momentum distribution and   equipressure surfaces
  We construct a new family of analytic models of black hole accretion disks in dynamical equilibria. Our construction is based on assuming distributions of angular momentum and entropy. For a particular choice of the distribution of angular momentum, we calculate the shapes of equipressure surfaces. The equipressure surfaces we find are similar to those in thick, slim and thin disks, and to those in ADAFs. 
L. Qian, M.A. Abramowicz, P.C. Fragile, J. Horak, M. Machida, and O.   Straub