(a) Cylindrical geometry model and (b) corresponding volume mesh consisting of 310 228 elements and 56 128 nodes. (c) Pressure profile along the 3D vertical pipe with the maximum test inlet pressure of 2.5 Pa and outlet pressure of 1.01 Pa. In-between the inlet and outlet pressure is a gradient that is consistent with imposed values and the physical geometry investigated. (d) Velocity profile along the 3D vertical pipe with the imposed no slip boundary conditions on the surface of the pipe and maximum velocity profile at the middle of the pipe corresponding to the parabolic flow profile.