Hi guys i am new to CFX. SO for simple analysis of flow through pipe i had given boundary conditions like at inlet mass flow rate as 10Kg/s at outlet i set relative pressure to 0Pa and default domain to wall After solving this i am getting a negative mass flow at outlet. and even the mass flow contour drawn at inlet showing a variation of 2Kg/s to .5Kg/sec instead of given 10 Kg/s. Can any body tell me what is this indicates and what are the modifications need to be taken.

Pipe is of 25mm radius and 500mm length

Thanks in advance

Negative mass flow simply signifies that you have outflow of mass. And what do you mean with mass flow contour (mass flow is an integral quantity, so how can you plot a contour)?