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Table Of Contents
Chapter 5 Working with Hydrology Commands
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To calculate hydraulic values for rectangular weirs
1 From the Hydrology menu, choose Weirs ä Rectangular to display the
Rectangular Weir Calculator dialog box.
2 From the Solve For list, select the value you want to calculate. The available
values are: Flowrate, Width, Depth of Flow, and Coefficient.
NOTE
Do not enter the value for which you are solving. For example, if you select
Flowrate in this step, leave the Flowrate text box at 0. After you enter the
other values, the program solves for the Flowrate.
3 Select the Contracted Ends check box to use the contracted weir formula for
calculating the values.
If you clear the Contracted Ends check box, then the suppressed weir formula is
used to calculate the values.
4 In the Flowrate box, type a flow rate value for the weir.
5 In the Width box, type a width for the weir.
6 In the Depth of Flow box, type a depth of flow value.
7 In the Coefficient box, type a weir coefficient value.
You can also click Select to display the Rectangular Weir Coefficients dialog box
and select a coefficient. For more information, see Specifying a Rectangular
Weir Coefficient in this chapter.
NOTE
The weir coefficients that are provided with Autodesk Civil Design are
samples only. You must determine the weir coefficient based on the
geometry of the weir you are designing.