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http://hdl.handle.net/10136/500
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| Title: | Solute mixing in a fracture junction under equal and unequal flow conditions |
| Authors: | Wise, Jason S. |
| Issue Date: | 26-Aug-2009 |
| Abstract: | I conducted a series of experiments using a physical model of a fracture junction with simple geometry. The flow conditions in the experiments included equal flow, where the flow rates in all four fracture branches were identical; unequal flow, where the flow rates in the two inflow fractures were different but the flow rates in adjacent inflow and outflow branches were identical; and forced mixing (a type of unequal flow), where water from one of the inflow branches crossed to the opposite side of the junction and mixed with water from the other inflow branch. Forced mixing occurred due to the fact that the flow rate in one inflow branch was greater than the flow rate in the adjacent outflow branch, resulting in overflow to the opposite outflow branch. The goal of the experiments was to determine how the mixing behavior of a solute would be effected by the Peclet number at the junction in each of these flow conditions.
In the case of equal flow, the present work verified the findings of Li (1995), showing that partial mixing occurs at Peclet numbers between approximately 1 and 200. Complete mixing occurs below this range, and streamline routing occurs above this range. Photomicrographs of the equal flow case illustrate the three types of mixing behavior and show that upstream diffusion occurs at low Peclet numbers. In the case of unequal flow without forced mixing, where the water from each inflow branch exits through the adjacent outflow branch, the transition between mixing states occurs at a lower range of Peclet numbers than in equal flow conditions, so that complete mixing was not observed at Peclet number of 1. In the case of forced mixing, the transition occurs at still lower Peclet numbers, too low to be observed in the present work. |
| URI: | http://hdl.handle.net/10136/500 |
| Appears in Collections: | Theses
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| Wise, Jason S..pdf | | 3571Kb | Adobe PDF | View/Open |
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