Hello!  I have a problem in Solidworks Flow Simulator relating to flow through a very simple pipe, but I’m getting results that don’t make any sense to me.

I have a long, straight pipe of 4.5 mm in diameter.  The pipe in question is 3400 mm long.  At 2200 mm from the left end of the pipe, I have another pipe of diameter 4.5 mm and length 50 mm joining the first pipe at a 45 degree angle.

That’s the setup.  I used the automatic lid function in flow simulator and want to run an internal analysis on the flow in the pipe.  I have placed a total pressure of 1.5 bar on both the left end of the pipe and on the 45 degree pipe.

Primarily, I am concerned with the flow in the left section of the pipe, prior to the 45 degree pipe.

Intuitively (considering the system as an electrical circuit), I have two “voltage” supplies that are equivalent and a resistor in between (the left section of pipe), followed by another resistor (the right section of pipe) leading to “ground” – the right end of the pipe at environmental pressure.  I would say that there should be no flow in the left section of the pipe – only flow in the right section.  However, Solidworks flow simulator is saying that there is flow in both sections of the pipe.

Is the flow simulator incorrect, or is my understanding of what should happen flawed?

Any help is appreciated!

          Thanks.