Hydraflow Storm Sewers Extension 2011: Flow Calculation Error

[rdisacks]

Does anyone use this program much or know of any bugs? I keep getting a "flow calculation error". I have entered known Q's into the pipes. I even simplified my system to just a straight line of 4 oversized pipes, 4 structures, and an outfall and it still gives me an error......

The error states:  "An error occurred during flow calculations on Line 3.  Please check line Flow Data and/or IDF-curves for integrity."

Any help would be greatly appreciated!

Thanks

[ToddRogers-WPM]

Have you run the analysis?  When you hit run, at the bottom of the screen, change the HGL to "Normal".  See if this helps.  If you like, attach the .stm file here and I will take a look at it for you.

[rdisacks]

Yes, I have run the analysis. I simplified the system to be very basic, just two pipes and two structures and the outfall and am still getting a flow calculation error. However, I run a full flow analysis it works...but I want to know my user entered flows. I'm thinkinh there is something very basic that I'm just not seeing.....

I have attached my simple system set-up....take a look. Thanks

[ToddRogers-WPM]

Ok.  Your first line has a Known Q of 0.  Also, there are no Drainage Areas specified.  And lastly, you will need to specify a Runoff Coeffient.  Usual grass areas use 0.55 for Runoff Coeff.

[ToddRogers-WPM]

I have attached your .stm file.  Just an example of what it should look like.  I ran the analysis and it was fine.  Remember when you run the analysis, to change the starting HGL to Normal.  See pic...

[rdisacks]

I thought on Line 2, I had a user entered flow. Also, I was under the impression if I manually enter the flow for the pipe, then I don't have to mess with adding the C*I*A data...Thanks

[ToddRogers-WPM]

I wish it was that easy

[rdisacks]

I know. I have all my contributing areas to each of the pipes already calculated in my non-simple design file. I just want to know my HGL profile. Could I manipulate the IDF file so it produces very low/negligable flows and still put in user-entered flows?

[ToddRogers-WPM]

You will need to adjust your cfs (cubic feet per second) for that.

[ToddRogers-WPM]

OR you can adjust the IDF's.  Sorry, busy day...lol.

[rdisacks · Accepted solution]

Thanks. I entered the local values for the 10-yr event into the IDF table for the major system I'm working on and everything seems to be working.... when I select the 10-yr event when I run it. No errors. And the HGL profiles seem to make sense. Although, I didn't enter in any Areas, Tc's, and C's for the pipes. It seems to be using the "Known Q" value that I've entered and everything seems to be adding up in the results table