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Line 49: − − The 3 dimensional equations make use of the hydraulic radius (''P''/''x''), where ''x'' is the perimeter (m) of the facility. <br>+ − Maximizing the perimeter of the facility directs designers towards longer, linear shapes such as [[infiltration trenches]] and [[bioswales]]. + − To calculate the required depth:+ − :<math>d=a[e^{\left ( -bD \right )} -1]</math>+ − Where − <math>a=\frac{A_{p}}{x}-\frac{i I}{A_{p}q'}</math> − and − <math>b=\frac{xq}{nP}</math> − − The rearrangement to calculate the required footprint area of the facility for a given depth is not available at this time. Elegant submissions are invited. − − To calculate the time (''t'') to fully drain the facility: − <math>t=\frac{V_{R}A_{p}} {q'P}ln\left [ \frac{\left (d+ \frac{A_{p}}{P} \right )}{\left(\frac{A_{p}}{P}\right)}\right]</math>
→Calculate drawdown time
==Calculate drawdown time==
==Calculate drawdown time==
[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m<sup>2</sup>.<br>
[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m<sup>2</sup>.<br>
From left to right x = 12 m, x = 14 m, and x = 16 m]]
From left to right x = 12 m, x = 14 m, and x = 16 m]]
To calculate the time (''t'') to fully drain the facility:
:<math>t=\frac{V_{R}A_{p}} {q'P}ln\left [ \frac{\left (d+ \frac{A_{p}}{P} \right )}{\left(\frac{A_{p}}{P}\right)}\right]</math>
This 3 dimensional equation makes use of the hydraulic radius (''A<sub>p</sub>''/''P''), where ''P'' is the perimeter (m) of the facility. <br>
Maximizing the perimeter of the facility directs designers towards longer, linear shapes such as [[bioswales]].
[[category: modeling]]
[[category: modeling]]
[[category: infiltration]]
[[category: infiltration]]