Significant Reversed Flow at Outflow Problems [ANSYS FLUENT]
 

Hello,

I'm running a closed domain cardiovascular simulation comprised of 2 mass flow inlet boundary conditions with 5 outflow boundary conditions. When the solution is calculated, the boundary conditions are held correctly but there is a huge amount of reversed flow happening at the boundaries. I have had the solution converge before to what looks like an appropriate flow field but I had to change a boundary condition and re-run the simulation. Now it isn't converging.

I previously got the solution to converge by reducing the relaxation factors and starting with an initial velocity. Any ideas on how to eliminate reversed flow? Any help is appreciated.

For those of you wondering, I think I may have solved my problem by initializing the solution using one of my inlets. As it turns out, initial conditions are important. :D