管内堆積層上の水の流れに関する理論的考察

管路における堆積層を伴うスラリーの流動に関する研究

抄録

In a pipeline transport of coarse solid particles, it is important to analyse the mechanism of slurry flow with the stationary bed in a pipe. The object of this paper is to present the condition of incipient motion of solid particles resting on the stationary bed in a horizontal pipe. The first step of this analysis was the assessment of the effect of cross-sectional shape above the bed on flow resistance. The next one was the study on the applicability of the Shieldsdiagram obtained in open channel flow to closed conduit flow. Based on these studies, an analytical work was developed to derive the relationships of average flow velocity, volumetric flow rate and hydraulic gradient of free flow area above the stationary bed against the thickness of bed.
The result of the presented analysis may be summarized as follows:
1) the head loss due to water, which is necessary for the calculation of the slurry flow with the stationary bed, could be reasonably determined; and
2) the experimental relationship deduced by Gibert and Condolios et al.
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was valid for practical purposes as long as the level of deposition do not exceed the pipe radius.