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1. Visual observation of flow patterns for scale-model inlet manifold(s).
Experiment Set 1
2. Pressure differential measurements from end-to-end of a scale-model inlet manifold. Results seen here.
Experiment Set 2
3. Direct measurements of water flow from either end of a scale-model inlet manifold. Results seen here.
Experiment Set 3
4. Visual observation of flow patterns within a scale-model sediment tank. Results seen here.
Experiment Set 4
Discussion and Conclusions
The following preliminary conclusions were reached:
Water exiting the manifold does so with a strong horizontal velocity component. This horizontal velocity can, if unchecked, create horizontal flow patterns that amplify imbalanced flow distribution in the manifold discharge and can create circular or horizontal flow patterns in the sediment tank, reducing its effectiveness. This effect can also create undesireable local flow velocities in the vicinity of the manifold that exceed the anticipated design velocities calculated from normal orifice flow alone.
A pressure recovery effect creates more exit flow at the end of the pipe farthest from the source than at the source end. The net effect of this unbalanced flow pattern may be circular flow in the sediment tank and non-optimal tank performance. However, the magnitude of this effect may not match "simple theory" which assumed uniform flow patterns.
Further Experiments
After sufficiently proving the existence of pressure recovery and discovering the circular flow patterns caused by the horizontal component of velocity coming out of the ports, our team's focus shifted to testing of potential design options. Our experimentation made use of dye tests, as well as additional flow capturing experiments, home-made manometers, and small beaded media to track flow in the manifold. Our research lead us to design, test and evaluate multiple design options, as outlined here.