InfoSewer Minimum Travel Time Sensitivity

InfoSewer Minimum Travel Time Sensitivity

InfoSewer Minimum Travel Time Sensitivity

by dickinsonre
InfoSewer Minimum Travel Time Sensitivity

The three Run manager parameters, Maximum Number of Segments, Minimum Travel Distance and the Minimum Travel Time in InfoSewer and H2OMAP Sewer affect the shape and flow attenuation of the flow in a link.  The effect of decreasing the Minimum Travel Time is to reduce the peak flow and spread out the flow as the number of segments increases(Figure 1).  The larger the Minimum Travel Time, which has the effect of decreasing the number of segments in a link up the limit of the parameter Maximum Number of segments, the smaller the peak and the more attenuation of the flow in InfoSewer.

There is three ways to control attenuation in InfoSewer: (1) use the flow attenuation option, (2) increase the Maximum Number of Segments per link and (3) decrease the Minimum travel distance.    You can also use all three parameters to make more segments per link for long links and only a few segments for short links.
Figure 1.  Effect of the Minimum Travel Time in InfoSewer and H2OMAP Sewer



Comments

Post a Comment

Popular posts from this blog

Orifice and Weir flow calculations

Note: Orifice and Weir Flow Computations The orifice flow calculation proceeds as follows: 1. Initially and whenever the setting (i.e., the fraction opened) changes, flow coefficients for both orifice and weir behavior are computed as follows: a. For side orifices: Define Hcrit = h/2 where h is the opening height. b. For bottom orifices: i. For a circular orifice, compute area over length (i.e., circumference) as AL = h /4. ii. For a rectangular orifice compute AL = h*w/(2*(h+w)) where w is the opening width. iii. Compute Hcrit = Cd*AL/0.414 where Cd is the orifice discharge coefficient. At step 1b, the critical head for the bottom orifice, where orifice flow turns into weir flow, is found by equating the result of the orifice equation to that of the weir equation Cd*Area*sqrt(2g)*sqrt(Hcrit) = Cw*Length*sqrt(Hcrit)*Hcrit or Hcrit = (Cd * Area) / (Cw/sqrt(2g) * Length) The value of Cw/sqrt(2g) for a sharp crested weir is 0.414.
Read more

SWMM 5 Error Messages

Engine Error Number Description ERROR 101: memory allocation error.                                                                                             ERROR 103: cannot solve KW equations for Link                                                                                   ERROR 105: cannot open ODE solver.                                                                                              ERROR 107: cannot compute a valid time step.                                                                                     ERROR 108: ambiguous outlet ID name for Subcatchment                                                                            ERROR 109: invalid parameter values for Aquifer                                                                                  ERROR 110: ground elevation is below water table for Subcatchment                                                         
Read more

EMC Washoff in SWMM5

Image
There are four steps to using EMC concentrations in your network: 1. Define your pollutant by adding a pollutant using the Data=>Quality=>Pollutant command : 2. Define the Land Use by using the Data=>Land Uses command or the Land Use Editor: 3. Define Buildup to be None by clicking on the None Tab: 4. Define the EMC Washoff concentration by clicking on the Washoff Tab: This is where you would add a GW concentration More: http://www.swmm2000.com/
Read more