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The effect of the clearance height on the pressure coefficient drop was also analyzed. It can be seen that the pressure coefficient drop is independent of the change in clearance height after the clearance height is greater than a critical value. Figure 13 shows that after a critical value of 1, the pressure coefficient drop is constant. This phenomenon can be explained by looking at figure 14 below. Figure 14 shows the turbulent dissipation rate for clearance heights of 1b and 1.5b. It can be observed that the maximum dissipation rate is equal for both reactors. A recirculation zone begins to form at the bottom of the reactor when the clearance height is larger than 1b. A similar argument can be made for the values of maximum velocity. A clearance height less than 1b results in a higher pressure coefficient drop as it creates an additional constriction in the flow increasing expansion losses. It is therefore recommended for the design team that the clearance height be at least the same as the baffle spacing. The correlation between pressure coefficient drop and maximum velocity should also be noted. Add the theoretical connection using the pressure drop in an expansion. The conclusion that there is no need to make the clearance height larger than 1b is noteworthy. This will make it possible to handle higher flow rates with the same channel width since we are dealing with a constraint that requires neighboring baffles to overlap in the center of the reactor to prevent short circuiting.
Figure 14. Comparison of Turbulent Dissipation Rate for Clearance height of 1b and 1.5b
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- Measure the Gθ value from FLUENT
- Analyze the region of very high energy dissipation along the wall near the contraction and explore methods to reduce the energy dissipation in this zone
- Devise improved methods of creating more uniform energy dissipation in the reactor to enhance flocculation efficiency
- Analyze the effect of changing the ratio of b/h all the way to the extreme where the baffles don't overlap in the center of the reactor. This is important to learn what will happen as we design for larger flow rates. Larger flows require the spacing between baffles to increase. If we hold the reactor depth constant that will increase the ratio of b/h.
- Better understanding of different turbulence models
- Model droplet collision - breakup
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