Research relevance. Climatic changes determine the need to ensure a high productivity of drained lands through the use of appropriate adaptive measures for regulating and accumulating moisture in the soil. Therefore, the issue of changing approaches to the creation and operation of water reclamation facilities on drained lands gains relevance. Relevant are also changes in the methodology of projects for drainage systems construction and reconstruction and their optimal design solutions (type, design, systems parameters, and components of their technical elements) in the closed collecting and drainage network. In this case, the closed collecting and drainage network is a key element of the drainage system, which can operate in the drainage and soil moisture regime.
Aim of the study is to reveal new approaches to improving the methods of dimensioning the closed collecting and drainage network of drainage systems operating in the regime of drainage and soil moisture, based on justifying the relationship and considering the impact of network efficiency on the efficiency of water regulation on drained lands.
Research methods. The analysis and generalization of the existing researches and methods on justification of the type, design, and parameters of the closed collecting and drainage network in the regime of drainage and soil moisture of the drained lands is executed. Systems approach and systems analyses were used to determine the existence of a structural relationship between the operation regime of the closed collecting and drainage network and the water regime of the drained lands. In performing the theoretical research, methods of mathematical modeling of the hydrodynamic structure of turbulent flow in pressure pipes using Navier-Stokes differential equations were applied. To confirm the adequacy of the obtained analytical models, the methods of statistical processing of experimental research results by Nikuradze I., Shevelyov F.O., and Altshul A.D. were used.
Research findings and main conclusions. Thus, based on the performed theoretical and experimental research, we have proposed relatively new scientific positions in contrast to the semi-empirical theories for determining the hydrodynamic structure of the flow in the pressure pipe. This allows for dimensioning the entire hydrodynamic structure for all areas of the turbulent flow based on the application of the obtained universal equations. That is, we can construct a distribution profile of the total turbulent kinematic viscosity, averaged velocity, tangential stresses, and angular velocities of fluid particles.
Prospects. The presented approach will make it possible to determine the efficiency of flow in drainage pipes and in a closed collecting and drainage network. Also, this approach will further be helpful in improving the methods of designing and dimensioning technological and structural parameters of the network and ensuring the overall technical, technological, economic, and environmental efficiency of drainage systems.
