| Product(s): | CivilStorm, SewerCAD, SewerGEMS, StormCAD |
| Version(s): | 08.XX.XX.XX and higher |
| Area: | Layout and Data Input |
OpenFlows Storm and Sewer products have been supporting several Structure Loss methods for node elements (manholes, catchbasins and transitions) with the release of each version. This article explains which methods are supported by each solver and version.
Absolute - The user will enter the exact head loss in feet or meters. Enter zero to model no structure loss.
Standard - The user will enter the standard headloss coefficient K. The headloss will then be calculated based on the formula: headloss = K*V^2/2g. The standard method calculates structure headloss based on the exit pipe's velocity. The exit velocity head is multiplied by a user-entered coefficient to determine the loss. For numerical stability reason an empirical velocity filter is used when the velocity is larger than 5.0 ft/s as follows: v’ = 5.0 + 0.1*(v -5.0)
Generic - The generic method computes the structure headloss by multiplying the velocity head (V^2/2g) of the exit pipe by the user-entered downstream coefficient and then subtracting the velocity head of the governing upstream pipe multiplied by the user-entered upstream coefficient.
HEC-22 Energy (2nd Edition) and HEC-22 Energy (3rd Edition) - this is the standard HEC-22 headloss method, which correlates structure headloss to the velocity head in the outlet pipe using a coefficient, which accounts for several factors such as benching, plunging, diameter, etc. This method was changed between the two latest editions of the HEC-22 manual.
AASHTO - this is based on power-loss methodologies, which accounts for contractions, expansions and bends.
Flow-Headloss curve - this method allows you to enter a rating table of flow versus headloss across the structure.
For more information on the above headloss methods, please see the Help documentation
CONNECT EDITION, 2023 and higher
|
Solvers |
Generic (K) |
Absolute |
Standard |
Hec-22 Energy 2nd Edition |
Hec-22 Energy 3rdEdition |
AASHTO |
Flow Headloss Curve |
Hec-22 Minor Loss |
|
Implicit |
Y |
Y |
Y |
Y |
N |
N |
N |
N |
|
Explicit |
N |
Y |
Y |
N |
Y |
N |
N |
N |
|
Convex |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
|
Rational |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
V8i SELECT SERIES 5
|
Solvers |
Generic (K) |
Absolute |
Standard |
Hec-22 Energy 2nd Edition |
Hec-22 Energy 3rdEdition |
AASHTO
|
Flow Headloss Curve |
Hec-22 Minor Loss |
|
Implicit |
Y |
Y |
Y |
Y |
N |
N |
N |
N |
|
Explicit |
N |
Y |
N |
N |
N |
N |
N |
N |
|
Convex |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
|
Rational |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
V8i SELECT SERIES 4
|
Solvers |
Generic (K) |
Absolute |
Standard |
Hec-22 Energy 2nd Edition |
Hec-22 Energy 3rdEdition |
AASHTO |
Flow Headloss Curve |
Hec-22 Minor Loss |
|
Implicit |
Y |
Y |
Y |
Y |
N |
N |
N |
N |
|
Explicit |
N |
Y |
N |
N |
N |
N |
N |
N |
|
Convex |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
|
Rational |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
V8i SELECT SERIES 3
|
Solvers |
Generic (K) |
Absolute |
Standard |
Hec-22 Energy 2nd Edition |
Hec-22 Energy 3rdEdition |
AASHTO |
Flow Headloss Curve |
Hec-22 Minor Loss |
|
Implicit |
Y |
Y |
Y |
Y |
N |
N |
N |
N |
|
Explicit |
N |
Y |
N |
N |
N |
N |
N |
N |
|
Convex |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
|
Rational |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
N |
HEC-22 2nd edition energy loss calculations with the Implicit solver
Headloss from Entrance and Exit loss coefficients on a conduit