h1. Experiment 2: February 28, 2010
h2. Setup
This experiment consisted of one 10' Manifold with 1 in. holes drilled every 5 cm on one side of the pipe. This resulted in an Am/ApAvc = 1.
h2. Results & Discussion
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!10'ManifoldResults.png|width=450px!
h5. Figure 1: 10' Manifold Results compared with theoretical expectations
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The results of our second experiment seem to reaffirm the results that we found in the first experiment, despite the problems with data collection that existed in the first experiment. The flow starts low then peaks in the first quarter of our manifold and then gradually decreases after that. And as showed in the graph, this is completely opposite what the theory of pressure recovery predicts.
The good news with these results is that the flow from the ports might be sufficiently uniform for it to work in the AguaClara plants. The mean velocity is 0.214 m/s and has a standard deviation of 0.021 m/s, which might be low enough variation for the AguaClara plants. The mean velocity might be a little high when considering the restriction of preventing floc breakup as there is an average energy dissipation rate of 19 mW/kg when the max allowable to maintain flocs is 10 mW/kg. After considering the fact that the manifold is oriented with the ports pointed downwards in the sedimentation tank, we have realized that scour velocity is not as big of an issue in our manifold as we thought.
We still do not understand the fluid mechanics of what is happening in the manifold and need to investigate that further. We plan on doing this by pushing the boundary of the ratio Am/ApAvc. Theory says that the smaller that ratio gets, the more pressure recovery should dominate and the higher the velocity should be at the end of the manifold compared with the beginning of the manifold. | 