Fully development flow test
 

Hi all,
I was trying to model a straight tube with aneurysm passing blood flow. To make sure that the fully development assumption will happen in the tube, I ran test as follow:
1-increasing the length of the tube from the output side
2-check the total pressure difference between inlet and one special plane after aneurysm.
My problem is I couldn't converge the results and with increasing the lenght until 6D still I can't draw a smooth line from the results. My supervisor thinks I have problem with mesh quality but the quality of my mesh with tetra and prism layer in boundary is between 0.17 to 0.99(ICEM) which I think is not bad. Any suggestion that could help me?

Thanks