The material used for the pipe should simulate a soft biological tissue, hence its elastic modulus ranges between 0.1 -1 MPa. In the literature I've found that this velocity is experimentally around 2 m/s. Regarding the boundary conditions, I have fixed the tube at both extremites, whereas for the fluid domain I have used a step function for for velocity (I later changed it with pressure) and constant pressure in outlet (I have also tried outflow, but according to the manual it doesn't work with pressure inlet). The geometry is quite simple, just a cylinder with 2.5mm radius.n