Author(s): Semaan Sarraf; Nassir El-Jabi
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Keywords: No Keywords
Abstract: It is especially frequent in late winter and early spring, after the ice breakup, ice floes move down to river. The important ice transport factors in ice release studies are: ice concentration, ice thickness, and ice velocity. These factors affect the hydrodynamic and ice dynamic conditions interactively. Although, several investigators have tried to obtain better understanding of ice conveyance, to date the ice transport data in natural rivers are still difficult to measure. Due to the difficulty in obtaining transient transport data of ice release in natural rivers, this problem is better approached through laboratory experiments and numerical simulations. This paper presents the results of a laboratory study associated with numerical simulation aimed at investigating the features and physical parameters of ice release in the flume. Experiments were performed using a prismatic laboratory flume using polyethylene blocks as well as with ice pellets in physical analogy to ice particles in rivers. The laboratory results showed that, in a more-orless uniform flow condition, the peak of area concentration was retarded. After initial release the velocity of solid particles accelerates in the upstream portion of the flume and became approximately drifting with water velocity at certain downstream location. The area concentration of polyethylene blocks was more retarded along the flume than that of pellets; and the mixture of polyethylene blocks and pellets produced extra retardation effect on transport of solid particles, compared with that of single-size solid particles. The numerical simulations based on MacCormack scheme of ice transport model then were carried out for sensitivity analysis and for reproduction of flume observation to get insight into, and quantify, the physical parameters that used and affecting the release of solid particles in the flume.
Year: 1994