Zero headloss through node when using the HEC-22 2nd Edition headloss method

Applies To 
Product(s): StormCAD, CivilStorm, SewerGEMS, SewerCAD
Version(s): 10.00.xx.xx, 08.11.xx.xx
Area:  Calculations
Original Author: Scott Kampa, Bentley Technical Support Group

Problem

Why are the computed headlosses shown to be zero in some inlets when using the HEC-22 headloss method? (2nd edition)

Problem ID#: 58020

Solution

This is occurring because the HEC-22 method does not apply to an inlet without conduits coming into and out of the inlet. For instance, the upstream-most inlet will always have a headloss of zero with this method since there is no conduit coming into it. In such cases, it is recommended to use the Standard method with a headloss coefficient of 0.5, which is typical for entrance headlosses to a structure.

See Also

What are the differences between the HEC-22 3rd Edition and HEC-22 2nd Edition headloss methods?

Inlet flooding with the HEC-22 Third Edition headloss method, but not with the HEC-22 Second Edition headloss method

  • Created by Bentley Colleague
  • When: Tue, Mar 31 2015 4:43 PM
  • Last revision by Bentley Colleague
  • When: Wed, May 24 2017 4:49 PM
  • Revisions: 2
  • Comments: 0
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