Changes

==Calculate drawdown time==

==Calculate drawdown time==

[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m².<br>

[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m².<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]]

The 3 dimensional equations make use of the hydraulic radius (''P''/''x''), where ''x'' is the perimeter (m) of the facility. <br>

To calculate the time (''t'') to fully drain the facility:

Maximizing the perimeter of the facility directs designers towards longer, linear shapes such as [[infiltration trenches]] and [[bioswales]]. 

:<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>

To calculate the required depth:

This 3 dimensional equation makes use of the hydraulic radius (''A_p''/''P''), where ''P'' is the perimeter (m) of the facility. <br>

:<math>d=a[e^{\left ( -bD \right )} -1]</math>

Maximizing the perimeter of the facility directs designers towards longer, linear shapes such as [[bioswales]]. 

<math>a=\frac{A_{p}}{x}-\frac{i I}{A_{p}q'}</math>

<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>

[[category: modeling]]

[[category: modeling]]

[[category: infiltration]]

[[category: infiltration]]