2.0

Calculating Pipe Flow and Other Hydraulic Values by Using the Hazen-Williams Equations
515
Specifying a Hazen Williams Roughness Coefficient
In the Hazen-Williams dialog box, there is a Select button next to the
Coefficient box. Use this command to display the Hazen-Williams Roughness
Coefficients dialog box and specify a Hazen-Williams roughness coefficient
from a table.
To specify a Hazen-Williams roughness coefficient from a table
1 In the Hazen-Williams dialog box, click the Select button next to the
Coefficient box to display the Hazen-Williams Roughness Coefficients dialog
box.
2 Select a coefficient by placing your cursor in the appropriate column and
clicking by anywhere in the text box that contains the value you want to use.
Use the navigation buttons on the right side of the dialog box to move through
the list of descriptions and coefficients.
You can add a new roughness coefficient to the table:
n
Click Insert to add a new row above the row you currently have selected.
n
To add data, select an empty text box, and type the new description and
coefficient.
3 Click OK to return to the Hazen-Williams dialog box.
Calculating the Flow for Rectangular Pipes Using
the Hazen-Williams Equations
To calculate the flow for rectangular piping values using the Hazen-Williams
equations
1 From the Hydrology menu, choose Pipes
ä
Hazen-Williams Rectangular to
display the Hazen-Williams dialog box.
2 From the Solve For list, select the value you want to calculate. The available
values are: Flowrate, Length, Headloss, Coefficient, and Width.
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.