Difference between revisions of "Flow through an orifice"

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Orifices are simply holes which restrict the flow of water. They may be used at the bottom end of an LID practice to add some [[flow control]].


<math>Q= B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot h}</math>
<math>Q= B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot h}</math>

Revision as of 22:37, 20 November 2018

Orifices are simply holes which restrict the flow of water. They may be used at the bottom end of an LID practice to add some flow control.

Where:

  • L is the length of perforated pipe (m)
  • B is the clogging factor (between 0.5 (for matured installation) and 1 (for a new perfectly performing BMP)),
  • Cd is the coefficient of discharge (usually 0.61 for a plate, or 0.8 for a pipe),
  • Ao is the area of the orifice (m2/m),
  • g is acceleration due to gravity = 9.81 m/s2, and
  • h is the head of water over the centre of the orifice.

See also[edit]