2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/124589Two general-relativistic hydrodynamical models are considered: a model of self-gravitating static configurations of perfect fluid and a model of steady accretion of fluid onto a black hole. We generalise analytic results obtained for the original polytropic versions of these models onto a wider class of barotropic equations of state. The knowledge about the polytropic solutions is used to establish bounds on certain characteristic quantities appearing in both cases.22 pages. To appear in Acta Phys. Pol. BGeneral Relativity and Quantum Cosmologytext