Justification of the geometric and hydraulic parameters of irrigation pipelines for drip irrigation systems of gardens

Abstract

Purpose: to develop a methodology for determining the geometric and hydraulic parameters of irrigation pipelines in drip irrigation systems for gardens. Materials and methods. The theoretical basis of the study was the known dependencies for determining pressure losses in pipelines. Experimental studies of pressure losses in an irrigation pipeline were conducted at the experimental site of the Donleskhoz forest nursery on the irrigation pipeline model with a total length of 125 m and an internal diameter of 57.6 mm. In the sprinkler’s working section with a length of 120 m, 40 water outlets simulating irrigation pipelines are arranged with a step of 3.0 m. Pressure losses within the sprinkler’s working section were determined for four variants of the irrigation pipeline flow rate. Results. For theoretical determination of pressure losses in an irrigation pipeline, the Darcy – Weisbach equation adapted to the condition of flow discrete uniform selection along its length was adopted. For the experimental site conditions, pressure losses in the irrigation pipeline were calculated using seven known calculation dependencies. Significant discrepancies in pressure losses amounting to 10.24–21.57 % of the average, were identified, which necessitated experimental studies. An analysis of the experimental data resulted in a Darcy – Weisbach correction coefficient of 0.3575. Taking this coefficient into account, the pressure losses in the sprinkler were calculated, the results of which deviate from the experimental values by 2.6–6.0 %. Conclusions. As a result of the research, a methodology for determining the geometric and hydraulic parameters of irrigation pipelines in drip irrigation systems for gardens was developed. The novelty of this methodology lies in the use of an adjusting factor refined for drip irrigation system conditions. Its application will improve the accuracy of determining pressure losses in irrigation pipelines in the Reynolds number range from 24,509 to 147,473.