In this blog we example the Froude Number values computed in SWMM5 as equations, table, graphs and units. We use a QA/QC version of SWMM 5 that lists many more link, node, system and Subcatchment variables than the default SWMM 5 GUI and engine. This blog also applies to #InfoSWMM and any software the uses the #SWMM5 engine. SWMM 5 computes only one flow in the middle of the link but it uses depth, head, cross sectional area and hydraulic radius at the upstream, midpoint and downstream points of the link (Figure 1). The Froude # is computed at all three points and if you could see the Froude # you will see a jump at times in a single link (Figure 2).
|Figure 1. Computational points in #SWMM5|
|Figure 2. Three locations of the Froude Number - it is possible to see where the Hydraulic Jump occurs in the link.|