Experimental study on the hydraulic performance of buried retractable telescopic sprinkler irrigation systems

【Objective】Buried telescopic sprinklers are commonly used for irrigating lawns, gardens, and crops. While providing efficient and automated irrigation, they can result in uneven irrigation if not operating under optimal conditions. This paper examines the hydraulic performance and optimal working conditions of three widely used buried telescopic sprinklers in China.【Method】The experiment was conducted with sprinkler arranged in both square and triangular configurations. For each sprinkler and spatial configuration, we measured the uniformity coefficient (CU) and distribution uniformity coefficient (DU) under varying working pressures and nozzle spacings. The optimal operating parameters for each sprinkler were determined using indexes such as range, average sprinkler irrigation intensity, and irrigation uniformity.【Result】① When the working pressure ranged from 0.15 to 0.30 MPa and nozzle spacing was between 1.0R and 1.4R, the irrigation uniformity coefficient (CU) varied from 0.51 to 0.87 for all three sprinklers. At lower operating pressures, variations in pressure significantly impacted both CU and DU. ② As the operating pressure increased, the flow rate of all sprinklers increased, while the rotational speed first increased and then plateaued once the operating pressure exceeded a certain threshold. ③ The hydraulic performance and optimal configuration varied between the three types of sprinklers. Generally, Sprinklers a and c performed better in the triangular configuration, while Sprinkler b performed better in the square configuration.【Conclusion】The optimal configurations and working pressures for the three types of sprinklers are as follows: Triangular configuration, 0.30 MPa working pressure, and 1.1R-1.2R nozzle spacing for Sprinkler a; square configuration, 0.25 MPa working pressure, and 1.1R-1.2R nozzle spacing for Sprinkler b; and triangular configuration, 0.25 MPa working pressure, and 1.1R-1.2R nozzle spacing for Sprinkler c.