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Testing for Three Limiting Parameters of Foam Formation from Water Jets
The experiment proved (how were these proven?) that the three parameters: the average velocity of jets, the type of surface, and the length the water travels down the incline, all matter. To test for the significance of the average velocity of the jets we increased flow rate from 380ml/min to 416 ml/min (This flow rate is not insignificant and it was 460 mL/min, but even that is not a significant change) using the same 0.17 (when did you mention a 0.17" before? You do not make it clear what this tubing is for. ) in diameter tubing and observed that there was more bubble formation with the higher flow rate in all instances of the experiment. From the experiment we also observed that when the jet hit a hard surface there was far less bubble formation then when it hit the water surface. This proves that in order for the inclined plane option to work, the plane cannot be partially submerged in water or have a significantly thick wet surface. The last parameter was tested by varying the proximity of the 45o inclined plane to the tube. We noticed that when the inclined plane further away from the opening of the tube the water there was far less bubble formation because the water traveled a longer length down the plane before it joined the water surface at the bottom. The closer the inclined plane was to the opening of the tube (so is this equivalent to where the jet would hit?) the more bubble formation was observed given that the distance the water traveled down the plane after hitting the plane surface was greatly reduced. It is believed that the shorter the length the water travels down the inclined plane the shorter time for the velocity of the water to gradually decrease with gravity. (The two sentences above are not clear. I'm not sure what you mean.)affirmed that the velocity of the jet, its length, and the type of surface it impacts are all limiting parameters. By observing the water jet at different flow rates it was observed that the length of the jet is dependent on the velocity of the jet. At low flow rates the length of the jet is shorter than at higher flow rates. As seen in Figure 1, the length of the jet refers to the part of the jet where the water surface is turbulence free and thus appears smooth and transparent. It is when the surface of the jet becomes sufficiently turbulent that air is entrained as the symmetry of the jet breaks during freefall. When the jet hits the water surface a void forms in the water and from the tip of this void an air bubble is pinched off creating foam; therefore, when the water jet hits a solid smooth surface there is no bubble formation.
Conclusions
At the end of all of our testing, we determined that inserting a 5cm-diameter pipe would effectively reduce the amount of bubbles produced by the LFOM, while not constricting the overall plant flow rate. Hopefully this design change can be easily executed in the AguaClara plants in Honduras to fix the foam problem. (This only works for a 7.5" I.D. LFOM. You cannot make this conclusion for the AguaClara plant. What about the inclined plane? Does this work??)