On the Laminar Flow Regime Forming in Pipelines for Drip Irrigation

Abstract

Under the new conditions of agricultural development and water resources, it is necessary to take into account the fact that the our country has a limited water resources, distributed unevenly over its territory. For this reason, water now appears as a limiting factor and becomes extremely important from an environmental and economic point of view. Saving irrigation water can be achieved by using efficient methods such as drip irrigation. In order to clarify the problem of sustainable use of water for irrigation, it is necessary to analyze the hydraulic and energy-efficient characteristics of water movement in irrigation systems and the conditions under which its transport and distribution to agricultural crops takes place. In the case of polyethylene - PE irrigation laterals for drip irrigation, a water quantity is consumed along their length. Under this condition, the flow rate gradually decreases and this leads to the formation of different flow regimes along the pipeline. In the present study, the question of the length of the part of the PE pipeline with laminar regime is considered, as well as the conditions predetermining the onset of this regime in PE pipelines ф 16/2 and ф 20/2. The conditions depend on the number of water localized outfalls, i.e. drippers, the magnitude of their flow rate, and the distance between them for a given assumed inner diameter and water temperature.