Laminar Flow Profile
One design constraint is to ensure that the flow is laminar. Turbulent flow cannot be modeled analytically and thus we would not be able to reliably predict plate settler performance.
The entrance region was checked to ensure that the parabolic velocity profile was fully established. This was done by calculating the distance that it will take laminar flow to become fully developed. This entrance region length is compared to the length of the tube settler, and if the ratio is less than one, then laminar flow is fully developed
The entrance regions are always less than the length of the plate settlers (Figure 7).
Figure 7: Entrance Region vs. Plate Settler Spacing