Difference between revisions of "Flow through an orifice"
Jump to navigation
Jump to search
Jenny Hill (talk | contribs) m |
Jenny Hill (talk | contribs) m |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| − | 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]] | + | 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> | ||
{{Plainlist|1=Where: | {{Plainlist|1=Where: | ||
| − | *''B'' is the clogging factor (between 0.5 (for matured installation) and 1 (for a new perfectly performing | + | *''B'' is the clogging factor (between 0.5 (for matured installation) and 1 (for a new perfectly performing orifice)), |
*''C<sub>d</sub>'' is the coefficient of discharge (usually 0.61 for a plate, or 0.8 for a pipe), | *''C<sub>d</sub>'' is the coefficient of discharge (usually 0.61 for a plate, or 0.8 for a pipe), | ||
| − | *''A<sub>o</sub>'' is the area of the orifice (m<sup>2</sup> | + | *''A<sub>o</sub>'' is the area of the orifice (m<sup>2</sup>), |
*''g'' is acceleration due to gravity = 9.81 m/s<sup>2</sup>, and | *''g'' is acceleration due to gravity = 9.81 m/s<sup>2</sup>, and | ||
| − | *''h'' is the head of water over the centre of the orifice. | + | *''h'' is the head of water over the centre of the orifice (m). |
}} | }} | ||
Latest revision as of 19:57, 17 March 2019
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:
- B is the clogging factor (between 0.5 (for matured installation) and 1 (for a new perfectly performing orifice)),
- 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),
- g is acceleration due to gravity = 9.81 m/s2, and
- h is the head of water over the centre of the orifice (m).