Changes

===Example calculation===

===Example calculation===

A part used roll of 100 mm diameter perforated pipe appears long enough to use for a stormwater planter project. The initial design for the planters includes 750 mm depth of filter medium, 50 mm rock mulch, and a further ponding of 300 mm. Upon inspection the pipe is found to have perforations of 8 x 1.5 mm on six sides, repeated every 3 cm along the pipe. To calculate the maximum flow rate, first the open area per meter is calculated:

A part used roll of 100 mm diameter perforated pipe will be used for a stormwater planter project, where each planter will be 8 meters long. The initial design for the planters includes 750 mm depth of filter medium, 50 mm rock mulch, and a further ponding of 300 mm. Upon inspection the pipe is found to have perforations of 8 mm x 1.5 mm on six sides, repeated every 3 cm along the pipe. To calculate the maximum flow rate from each planter, first the open area of the pipe must be calculated in m²/m:

<math>\frac{0.008\ m \times 0.0015\ m\times6}{0.03\ m }= 0.0024\ m^{2}/m</math>

<math>\frac{0.008\ m \times 0.0015\ m\times6}{0.03\ m }= 0.0024\ m^{2}/m</math>

Then:

Then the maximum flow rate per planter is calculated:

<math>Q_{max, p}=8\times 0.5\times 0.61\times 0.0024\ m^{2}/m\sqrt{2\cdot 9.81\ m/s^{2}\cdot \sum 1.1\ m}=0.0034\ m^{3}/s</math>

<math>Q_{max, p}=8\times 0.5\times 0.61\times 0.0024\ m^{2}/m\sqrt{2\cdot 9.81\ m/s^{2}\cdot \sum 1.1\ m}=0.027\ m^{3}/s</math>