Mass flow in a pipe

[hansmedina]

Hello, I have a flow through a pipe and I'm getting different values of mass flow rate in different cut planes. See image.

I think the flow is supposed to conservate through the whole path and be the same at every cut plane.

Why is a drop of 0.08 kg/s just 50 mm from the inlet? Does someone know why this happens?

Thanks

[abhishek.roy]

One of the possible reasons could be coarse mesh, poor quality elements.

Also, is the flow converged? Solver settings also affect flux accuracy - are you using 1st order or 2nd order schemes?