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The test was run for two different tube lengths, 1 m and 44.5 cm. The test was run at many different flow rates from head loss of 3 cm to 25 cm. The plants in Honduras induce, at the most, a head loss of 20cm. The test was meant to also allow for an end behavior analysis for over dosing.

<< insert the data of flow rate vs head loss for the two lengths>>

The head losses were taken from the experiment such that one hole below the base hole was only 1 cm of head loss. The length of the tubes, 44.5 cm and 1 m, were measured. The inner diameter was 1/8 in as given by the manufacturer for the experimental. The correction was applied to this diameter.

As can be noted from the graphs, calculated flow rates was consistently lower than the estimated low rate using the Hagen-Poiseuille equation. However, once the correction was added to the diameter of the tubing in the equation, the data matched much better.

Conclusions

This experiment confirmed that the Hagen-Poiseuille equation overestimated the actual flow rate and thus was providing an inaccurate estimate. However, the extent of this over/under estimation was previously difficult to determine. However, what is most interesting is the validity of the supposed correction. Using the values calculated from the experiments regarding the tube diameter provided a drastic improvement which may be a correction that could be the correct calculation. Also, because the inner diameter of the tube was 1/8th of an inch, small variation in inner diameter produce large changes in the data. Varying tube diameters should be tested to find if these minor variations are negligible at larger diameters. Varying tube lengths should be tested to consider the possibility of non-negligible minor head losses which, when considered, provide better fits to the calculated graphs.