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Type of Document	Dissertation
Author	Ismail, Hassan M.
URN	etd-04262004-152823
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-04262004-152823
Title	Study of suspended sediment in closed channels
Degree	PhD
Option	Civil Engineering
Advisory Committee	Advisor Name Title Vito Vanoni Committee Chair
Keywords	none
Date of Defense	1949-01-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Tests on a rectangular channel 10.5 by 3 inches in cross-section transporting water mixed with different amounts of sand are described in this thesis. Two sizes of sand were used. They are of mean sedimentation diameter of 0.10 mm. and 0.16 mm. Th experimental data were used to study both the effects of the presence of sand in suspension on the characteristics of the flow, and the concentration transfer coefficient at the middle of the channel, assuming a two-dimensional flow. It was found the the von Karman universal constant of turbulent exchange k decreases with the increase of the suspended material. k decreased to 0.20 when a total load of about 25 kilograms was added to the flume, i.e., 43 grams were added to each liter. No limit was approached for the decreased of k. The friction coefficient [...] was hardly affected by the presence of the sand when the velocity of flow was higher than a certain velocity. This critical velocity increased with the total load in the flume and the size of the sand used. It is related to the bed load and it is the velocity at which all the dunes on the bed are carried in suuspension. Below that critical velocity [...] exceeds that of clear water. The sediment transfer coefficient [...] was found to be equal to 1.5, the momentum transfer coefficient [...] for the 0.10 mm. sand, and to 1.3 [...] for the 0.16 mm. sand. [...] follows the normal parabolic form of [...] at the outer two-thirds of the channel and has a constant value at the middle third.
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