Experimental and Simulation Investigation on the Kinetic Energy Dissipation Rate of a Fixed Spray-Plate Sprinkler

Yisheng Zhang,Lingxia Yang,Hongyuan Fang,Bin Sun,Zhansong Li,Delan Zhu

doi:10.3390/w10101365

Yisheng Zhang, Lingxia Yang + Show 4 more

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https://doi.org/10.3390/w10101365

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Abstract

Sprinkler irrigation is promoted due to its remarkable advantages in water conservation, but the high energy consumption limits its development in a situation of energy scarcity. In order to determine the energy consumption of a fixed spray-plate sprinkler (FSPS), its discharge and initial trajectory velocity were investigated using a particle image velocimetry (PIV) technique and computational fluid dynamics (CFD) analyses. A nozzle diameter of 4.76 mm was used under windless conditions. Overall, good agreement between simulation results and experimental values was obtained. On the premise that the simulation method produced high accuracy, a series of simulations was performed with different nozzle diameters. The water distribution pattern, stream trajectory velocity and kinetic energy dissipation were analyzed. The results show that the jet produced at the nozzle is split by grooves after it hits the plate, with separation occurring earlier with decreasing nozzle diameter. The area of the flow cross-section of the outlet is mainly influenced by nozzle diameter rather than working pressure. The initial trajectory velocity of the grooves increases logarithmically with increasing working pressure. A high working pressure may not cause large kinetic energy dissipation. The dissipation rate of the FSPS ranged from 28.01–50.97%, i.e., a large kinetic energy rate was observed. To reduce this energy dissipation and improve water use efficiency, the structure of the FSPS should be optimized in further research.

Highlights

Agricultural production consumes enormous amounts of water, which is a threat to water resources [1]
The average velocities of water jetting from the grooves could not be obtained directly through the simulations; they could be calculated since the parameters of flow cross-section and mass flow rate were obtained
In our prior research [33], the jet velocity close to the sprinkler had no significant difference with small spacing, i.e., the calculation of initial trajectory velocity with numerical simulation method appeared valid

Summary

Introduction

Agricultural production consumes enormous amounts of water, which is a threat to water resources [1]. Sprinkler irrigation is characterized by high levels of water conservation [2,3,4,5]. Linear-move and center-pivot irrigation machines are widely used for their high degree of automation [6]. The earlier sprinklers equipped in these machines were high-pressure impact, and in recent years, increasing energy costs have shifted the focus to increasing the energy efficiency of agricultural sprinkler applications and led to the development of various low-pressure sprinklers. The two main low-pressure spray-plate sprinklers are the rotating spray-plate sprinkler (RSPS) and fixed spray-plate sprinkler (FSPS) [7]. Compared with RSPS, the fixed spray-plate sprinkler (FSPS)

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