Hi all,

I have a question regarding the validity of using the full pipe area for calculating headloss. For some models, especially older ones, it seems that using the full area can be used to stabilise otherwise unstable results. I understand why this would work, as flow velocity would be smoothed, thus reducing abrupt changes in headloss. My question is, when is it valid to do this?

The innovyze help only states that it can be used for backwards compatability with models built in Infoworks CS v4.5 or earlier. What is it about the way the equations are solved in earlier versions that makes this acceptable for these models? From what I can tell, the stabilising effect also works for newer models.