Хлапук, М. М. та Мошинський, В. С. та Безусяк, О. В. та Волк, Л. Р. та Khlapuk, M. М. та Moshynskyi, V. S. та BezusіaK, O. V. та Volk, L. R. (2019) АНАЛІЗ РОЗВИТКУ ТЕОРІЇ РУХУ ПОТОКУ В ТРУБОПРОВОДАХ. Вісник Національного університету водного господарства та природокористування (2(86)). с. 70-78.

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Анотація

В статті приведено аналіз літературних джерел щодо розвитку теорії руху потоку в трубопроводах. За узагальненими результатами аналізу та теоретичних досліджень розкрито зв'язок між ламінарним режимом руху та структурою потоку в трубопроводах.

Title in English

FLOW THEORY DEVELOPMENT ANALYSIS IN THE PIPES

English abstract

In order to improve the reliability of the hydraulic structures, it is necessary to improve the approach of the hydraulic calculation of pressure pipes. That is, we need to develop this theory of kinematic flow structure. The article describes the literature analysis about the development of flow theory in the pipes. It is noted that the graph of the dependence of the friction factor on the Reynolds number reveals only the flow regimes, but does not reveal the flow structure, which is necessary when considering the hydraulic calculations of the pipes. J. Stokes obtained the solution of the differential equation of S. Navier. His theoretical results completely coincide with the data of experiments conducted in small diameter pipes at low velocity (laminar flow regime). To close the differential equation, he considered the continuity equation and accepted the boundary conditions. J. Stokes found that the result obtained adequately describes the structure of the laminar flow for all points on the Nikuradze graph. The results of the analysis and the theoretical studies summarized. The relationship between the flow laminar regime and the flow structure in the pipes has described. Equations for calculating flow parameters determined: the equation of distribution of the averaged flow velocity in laminar flow regime, the distance from the pipe axis to the points with average velocities, the value of the maximum flow velocity, the ratio of the maximum velocity to the average flow velocity in the pipe, the value of the vortex components. It is proved that vortex lines are concentric circles whose centres located on the pipe axis. The equation of the particles rotation components of the flow and the maximum value of the angular velocity of rotation of the particles on the inner surface of the pipe were obtained. After integrating the Navier-Stokes differential equation, the pressure distribution equation in the pipe obtained. All equations that determine the flow structure expressed by Reynolds number and pipe friction factor. Such formulas have adopted to show the relationship between the flow regime and the flow structure. The flow structure for turbulent regime is still unknown. Therefore, we will describe the solution of this problem in the future articles.

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