To the determination of non-washable speed in the channels bed consisting of disconnected soils

Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, Tashkent, Uzbekistan

^* Corresponding author: l.samiyev@tiiame.uz

Abstract

This article analyzes the factors that influence the deformation process in the channel. When assessing the deformation process in channels consisting of disconnected soils, the method for determining nonwashable speed was analyzed, taking into account the trapezoidal shape of the channel, and, based on laboratory studies, a dependence was proposed for determining the non-washable speed. The values of the proposed dependencies are compared with the calculated values of the formulas of I.I. Levi, C.E. Mirtskhulava, V.A. Velikanova, B.I. Studenichnikov and A.M. Latyshenkov and obtained positive results. The proposed dependencies for the determination of non-washable speed are improved, taking into account turbulence and the laws of velocity distribution over the stream's depth. In the experimental researches, were used sand particles with different diameters d ≤ 0.315mm; 0.315mm < d ≤ 0.63mm; 0.63mm < d ≤1.25mm 1.25mm < d ≤ 2.5mm 2.5mm < d ≤ 5.0mm. Based on the analysis of the experimental data, the coefficients are as follows: η₁ = 1.41 for the bottom of the channel and η₂ = 1.52 for side slopes. The reliability of the results is justified by comparing the proposed calculation method with a study of other authors. Based on the research, constructed a plot of the velocity distribution and the depth of the stream. In these diagrams, preservation of the change in velocity along the depth of the flow was observed under various modes of motion. In all experiments, a process was observed-the smallest value of the flow velocity at the bottom and the highest at a depth of (0.8–0.9) h from the water level.