  A comparison is made between the Hagen-Poiseuille flow in rigid tubes and
networks on one side and the time-independent one-dimensional Navier-Stokes
flow in elastic tubes and networks on the other. Analytical relations, a
Poiseuille network flow model and two finite element Navier-Stokes
one-dimensional flow models have been developed and used in this investigation.
The comparison highlights the differences between Poiseuille and
one-dimensional Navier-Stokes flow models which may have been unjustifiably
treated as equivalent in some studies.
