Dependency for Determination and Distribution of Tangential Tensions of Flows in Smooth Pipes at Irrigation

The movement of fluids between the different layers within the flow, as well as the passing flow over solid surfaces, generates resistance forces - tensions, resulting from the viscosity of the fluid and the pulsational alteration of instantaneous velocities. The determination of these tensions is necessary and important for theory and practice of irrigation processes to achieve greater precision in agricultural activities. Increasing the energy efficiency of irrigation water transportation and distribution processes will be also achieved. For this purpose, many experimental, analytical and field studies have been carried out on turbulent tensions only for some specific condition or for real situation of a given facility, which actually shows the necessity of a realistic theoretical and analytical dependence on this subject. In the present work, a theoretical dependence is established for the distribution and values of turbulent tensions in flows in hydraulically smooth pipes, applicable to various velocity distribution diagrams under a power-graded law distribution, as well as for velocity distribution according to a logarithmic law function. The obtained relation is confirmed by experimental results given in the literature.