Danica
Ansys Employee

 

Hi Judith, 

So looking at the problem, you need to define either the inlet pressure or the inlet velocity profile, but not both. A velocity boundary varies the pressure until the velocity condition is met: a pressure boundary adjusts the mass flow until the pressure is met.  I would suggest a transient velocity profile defined at a point that is a suitable length upstream of the region of interest to allow for the flow to fully develop. Would suggest velocity over pressure as this will provide more stable solutions. 

Have a look at the following for how to define this: 7.6. Transient Cell Zone and Boundary Conditions (ansys.com)

What model are you using for blood viscosity?

Danica