Hazen–Williams Equation
The Hazen–Williams equation is an empirical relationship that relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction.
The flow velocity of fluid is proportional to the product of the Hazen-Williams coefficient of roughness, 0.63 power of hydraulic radius and the 0.54 power of the hydraulic grade line slope.
Formula
![QuantityVariable["v", "Speed"] == Quantity[0.849, "Meters"^0.37/"Seconds"]*QuantityVariable["C", "Unitless"]*QuantityVariable["R", "Radius"]^0.63*QuantityVariable["S", "Unitless"]^0.54](https://www.wolframcloud.com/objects/resourcesystem/marketplacestorage/resources/e7f/e7f2a2b5-184e-4f3c-aa58-8688eef5affc/Webpage/FormulaImage.png "Copy to Clipboard")
| symbol | description | physical quantity |
|---|---|---|
| v | flow velocity of fluid | "Speed" |
| C | Hazen–Williams coefficient of roughness | "Unitless" |
| R | hydraulic radius | "Radius" |
| S | hydraulic grade line slope | "Unitless" |