June 25, 2024, 10:04
|
mass flow not matching avg velocity for incompressible
|
#1
|
New Member
Daryn Bertelson
Join Date: Aug 2017
Posts: 3
Rep Power: 9
|
Hello,
I am running a simulation in Fluent on essentially a manifold with water (incompressible). I am trying to determine if the distribution is even out of the manifold outlets.
Unfortunately, I am getting some results that seem contradictory. The outlet that is closest to the inlet has the lowest mass flow rate, but also the highest average velocity magnitude.
One would think that a person could take the mass-averaged velocity magnitude and multiply it by the cross-sectional area of the outlet and the fluid density to get the mass flow rate across the outlet cross-section, but the values do not match.
The only explanation for this that I can come up with is maybe the average velocity registers as higher because of the energy in vorticity, like a "twisting" that doesn't necessary transport mass across the outlet, but still contributes to the average velocity increase.
Does this make sense? Has anyone seen something similar? I am inclined to trust the mass flow rate results as calculated by Fluent, but it is hard to explain to my clients that the flow rate is actually lower where the areas of higher velocities are occurring.
|
|
|