compressible flow through a pipe
 

Hi
I am trying to find a cold flow profile through a pipe. I have pipe of 1340 mm length and injecting oxygen at 6 bar from one end through a hole diameter of 5mm and exit diameter is 14mm.
The problem i am facing is that when I am solving for compressible gas using ideal gas in material and energy equation. The solution always diverges.
The boundary condition I gave for inlet is mass flow inlet and for exit is pressure outlet where I specify target mass flow as it is know to me.

can you please help me find reason why it diverges the solution.

thanks
rajiv