#INFOSWMM

Conduit Summary Report for better Model Output Analysis in InfoSWMM and InfoSWMM SA


Conduit Summary Report for better Model Output Analysis in InfoSWMM and InfoSWMM SA

The Conduit Summary report table presents a summary of some conduit result variables that could assist the modeler to easily analyze the drainage system. Using these report results alone, the user can easily identify conduit(s) that have surcharged and duration of the surcharging, the maximum flow that a conduit has conveyed within the reporting duration and the time of occurrence of this maximum flow, and some other essential parameters.

The following variables are displayed on the conduit flow summary report for all or selected conduits depending on the report scope ( i.e., show complete report/graph, select elements, use Domain, use selection set, use provided element ID(s)) chosen on the Output Report and Graph dialog box. The summary is provided for the entire reporting length specified in the simulation options – dates tab.

Description of buttons and fields in the report.

BUTTON NAME DESCRIPTION
Refresh Report
Print Report
Format Report
Format Column
Change Font
Copy
Sort Ascending
Sort Descending
Filtering
Find
Frequency Graph Click here to learn more.
Save Selection
Compare Report
Report Time Step
ID Conduit node identifier
Maximum Flow Maximum flow conveyed by the conduit within the simulation duration
Maximum Flow Class The flow Class of a link is based on the Flow Capacity (d/D) and the value of q/Qfull were q is the flow and Qfull is based on full depth Manning’s Equation.

  • Free Surface – if the Link Capacity is less than 1 or d/D is less than 1. It does not matter if q/Qfull is > 1
  • Backwater – if q/Qfull is less than 1 and Link Capacity >= 1 or d/D is less than >= 1. The flow is more than the Manning’s defined Qfull but the pipe is not full based on the value of d/D. There are some downstream conditions that is slowing up the flow so that q/Q is less than 1.
  • Exceeds Capacity – if q/Qfull > 1 and Link Capacity >= 1 or d/D is greater than >= 1.

Capacity is the current midpoint link cross sectional area / full pipe cross sectional area.

Ratio is the current flow / full flow (as calculated by Manning’s equation)

If at any time during the simulation, the link is defined as “Backwater” or “Exceeds Capacity” then these classifications will be reported as the Maximum Flow Class. It can be assumed that, hydraulically speaking, the flow class can be ranked as:

  • Free Surface -> Best
  • Backwater -> Medium
  • Exceeds Capacity -> Worst

Also note that Max Flow Class does not necessarily happen at the “Maximum Flow Day-Time”

 

Maximum Flow Day -Time Count Number of days (i.e., elapsed day) since the simulation start time to the instant when maximum flow at the conduit, and number of hours, counted from the day when maximum flow occurred at the conduit, to the time of occurrence of maximum flow at the conduit
Maximum Velocity Maximum velocity achieved by the conduit within the simulation duration
Max. Flow/Full Flow Ratio of Max. Flow to Full Flow. Full Flow is considered to be the flow calculated by the applicable flow equation (i.e. Mannings, Hazen-Williams or Darcy-Weisbach) that is dependent only on conduit properties (i.e. roughness, bed slope and cross-section) without respect to upstream or downstream conditions. Note that this will occur at the timestep of “Maximum Flow Day-Time”

In some models that display instability, results can be improved by using a Hotstart File and/or by reducing the Routing Timestep

Max. Depth/Full Depth Ratio of Max Depth to Full Depth. Note that this will not necessarily occur at “Maximum Flow Day-Time”
Reserve Capacity Difference between the normal full flow and maximum flow through the conduit.
Both End Surcharge Time This refers to the duration of time that the conduit is surcharged at its both ends.
Upstream Surcharge Time The duration of time that the conduit is surcharged at its upstream ends.
Downstream Surcharge Time The duration of time that the conduit is surcharged at its downstream ends.
Above-Full Flow Time Hours that conduit flows above full normal flow
Capacity Limited Time Hours that conduit is capacity limited
Total Flow Volume Total volume of flow conveyed through the conduit over the simulation duration.
Instability Index

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