Steady State Flow Analysis in InfoSWMM using an External Flow Time Series

Subject:  Steady State Flow Analysis in InfoSWMM using an External Flow Time Series

This can be easily created using a few steps in InfoSWMM.  The flow ramp is in the Routing Interface File.  The advantage is that you are able to have different ramps for the various nodes using this method.

Step 1:  In Run Manager Set up the Process Models Options to use just the External Inflow and NOT the Dry Weather Flow

Step 2.  Create the External Inflows File (see the help file for the format)

SWMM5 Interface File

300  - reporting time step in sec

1    - number of constituents as listed below:

FLOW CFS

2    - number of nodes as listed below:

36

24

Node             Year Mon Day Hr  Min Sec FLOW     

36               2002 01  01  00  00  00  0.000000 

24               2002 01  01  00  00  00  0.000000 

36               2002 01  01  01  00  00  1000.000000 

24               2002 01  01  01  00  00  1000.000000 

36               2002 01  02  01  00  00  1000.000000 

24               2002 01  02  01  00  00  1000.000000   

This file loads two manholes with a ramped inflow up to 1000 cfs to again drown out the wet wells and cause the pumps to have a steady flow.

Step 3.  Use the Tab File command and use the created External Inflows File

Step 4.  Run the simulation and see if the pump flows are constant.