In production, we often encounter the movement of hydraulic mixtures in pressure pipelines. Determination of the coefficient of hydraulic friction is important in the hydraulic calculation of pressure systems. When a homogeneous fluid moves to determine this coefficient, there are several formulas that have a theoretical basis and have experimental evidence. In a single-phase flow, the coefficient of hydraulic friction depends on the nature of the movement and the relative roughness of the pipe wall. The determination of this coefficient is much more complicated when solid particles move in the pipeline along with water. When moving slurries through pipes, gravity plays a significant role. Under the influence of excess mass, transported solid particles in the general case are unevenly distributed along the depth of the stream and their bulk moves at the bottom of the pipe. This circumstance determines the axial asymmetry of the velocity field, expressed in the upward displacement of the kinematic axis of the flow relative to the geometric axis of the pipe, corresponding to the location of the maximum averaged velocity and in the lower highly concentrated layers of the flow. As for the specific hydraulic resistances, in a pressure bearing flow, they are always greater than the specific hydraulic resistances in the corresponding flow of a homogeneous liquid. The article discusses the issue of experimental determination of the coefficient of hydraulic friction during the movement of hydraulic mixtures in pressure systems. The calculated dependences for the coefficient of hydraulic friction obtained based on the processing of experimental data by the methods of mathematical statistics are proposed and are reliable over a wide range of changes in the conditions of hydro transportation, and, therefore, they can be recommended for practical use.
Volume 12 | 07-Special Issue
Pages: 1332-1336
DOI: 10.5373/JARDCS/V12SP7/20202233