problem geometry in 2-d
 

Hello,

I am trying to simulate 2D multiphaze separation flow in a t-junction. The problem is that although i select for my boundary inlet the ''mass flow inlet'' option, FLUENT does not consider that the geometry is two pipes forming a T letter. Specifically, FLUENT considers that the pipes have square surface and not circular as it is in the real problem. As a result it gives me an inaccurate solution where the velocity values are wrong.
-What would i do to correct this problem?
-How may i make FLUENT regard my 2D pipes with circular geometry?

Thank you in advance!