Difference between revisions of "Flow through perforated pipe"

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<math>Q_{max, p}=B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot \sum d}</math>
<math>Q_{max, p}=B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot \sum d}</math>
{{Plainlist|1=Where:
{{Plainlist|1=Where:<sub>d</sub>'' is the coefficient of discharge (0.61 for a sharp edged orifice),
*''K<sub>m</sub>'' is the hydraulic conductivity of the filter media (mm/hr),  
*''B'' is the clogging factor (between 0.5 to calculate a for matured installation and 1 to calculate a new perfectly performing BMP),  
*''A<sub>p</sub>'' is the area of the practice (m<sup>2</sup>),  
*''C<sub>d</sub>'' is the coefficient of discharge (usually 0.61 for the sharp edge created by relatively thin pipe walls),  
*''d<sub>p</sub>'' is the depth of ponding (mm),  
*''A<sub>o</sub>'' is the total open area of the perforated pipe (m<sup>2</sup>/m),  
*''d<sub>m</sub>'' is the depth of the filter media (mm), and
*''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]]),  
}}
}}

Revision as of 02:37, 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 of the perforated 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),