Numerical modelization of the venous net in the cardiovascular system
The venous system allow the blood to come back to the hearth. This system in made by a net of vessel. For this reason, we have decided to model it with a net of vessels modelled with the 1-d reduction of the Navier-Stokes equation, obtained by integrating over the surfaces orthogonal to the axial axis. Moreover, in order to take into account the presence of the valves (which makes possible the blood to come back to the hearth) we introduce a new methodology for their modelization based on the characteristic variables. We introduce also a modelization of the muscle action which helps the blood to come back.