Difference between revisions of "Flow through perforated pipe"

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m (Jenny Hill moved page Flow through pipe to Flow through perforated pipe)
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*''B'' is the clogging factor (between 0.5 to calculate a for matured installation and 1 to calculate a new perfectly performing BMP),     
*''B'' is the clogging factor (between 0.5 to calculate a for matured installation and 1 to calculate a new perfectly performing BMP),     
*''C<sub>d</sub>'' is the coefficient of discharge (usually 0.61 for the sharp edge created by relatively thin pipe walls),  
*''C<sub>d</sub>'' is the coefficient of discharge (usually 0.61 for the sharp edge created by relatively thin pipe walls),  
*''A<sub>o</sub>'' is the total open area of the perforated pipe (m<sup>2</sup>/m),  
*''A<sub>o</sub>'' is the total open area per unit length of pipe (m<sup>2</sup>/m),  
*''g'' is acceleration due to gravity (m/s<sup>2</sup>)  
*''g'' is acceleration due to gravity (m/s<sup>2</sup>)  
*''Σ d'' is the total depth of bioretention components over the perforated pipe (mm) (e.g. ponding/[[mulch]]/[[filter media]]/[[choker layer]]),  
*''Σ d'' is the total depth of bioretention components over the perforated pipe (mm) (e.g. ponding/[[mulch]]/[[filter media]]/[[choker layer]]),  
*''O'' is the number of orifices per meter of perforated pipe.
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Revision as of 03:13, 25 February 2018

Manufacturers of perforated pipe are often able to provide the open area (m2) per meter length.

Where:d is the coefficient of discharge (0.61 for a sharp edged orifice),

  • B is the clogging factor (between 0.5 to calculate a for matured installation and 1 to calculate a new perfectly performing BMP),
  • Cd is the coefficient of discharge (usually 0.61 for the sharp edge created by relatively thin pipe walls),
  • Ao is the total open area per unit length of pipe (m2/m),
  • g is acceleration due to gravity (m/s2)
  • Σ d is the total depth of bioretention components over the perforated pipe (mm) (e.g. ponding/mulch/filter media/choker layer),
  • O is the number of orifices per meter of perforated pipe.