Title: Three-dimensional simulation of polytropic accretion discs
Abstract: We carried out three-dimensional simulations of the of the formation and evolution of accretion discs in close binary systems, using the Smoothed Particle Hydrodynamics method to solve the fluid dynamic equations. Although the runs presented here refer to an ideal gas with different polytropic indexes, and constitute the first stage of more physically complex forthcoming simulations, they nevertheless give some interesting results; the disc structure and dynamics are in agreement with standard models only for small γ-values; as a consequence of the z-resolution it is found that disc formation is inhibited for gamma equal to or greater than γ ≥ 1.2, which means that some 2D simulations of polytropic discs are meaningless; the disc is slightly asymmetric in the x–y plane and its profile is irregular and pulsating at the outer boundary.