SimScale CAE Forum

SIDEPOD outlet mass flow rate

In the above-shared link, how can I calculate the mass flow rate at the outlet of the sidepod?


Hi there!
Mass flow is calculated as:

mass_flow =ρAV


  • ρ=density

  • A = area of the outlet

  • V = the mean velocity at the outlet

You know the density of the fluid (it is an incompressible case, so it is constant everywhere). The area of the sidepod’s outlet can be calculated in your CAD software. So the only thing that is missing is the velocity value on the face.

Generally speaking, in this kind of problem, users tend to create internal simulations, and thus they can easily get the velocity at the sidepod’s outlet, as it is part of the domain and easy to extract results from.

For your case, there is no face that can be used to create a ‘Surface data’ set under the ‘Results control’, so a workaround is needed. Some things you can consider:

  • Add a few probe point set under the ‘Results Control’ prior to the simulation, that are located on the outlet of the sidepod. Then you could use the mean velocity value of them and use it as a reference velocity.

  • Use Paraview to extract the results of a slice located at the outlet. Then you can use an excel sheet and gather all the points that are located within the boundary of the face, so you can calculate their mean value.

If anyone else has another recommendation, please go ahead and let us know :smiley: