Analysis of droplet size and distribution for micro-sprinkling hose based on LPM

Abstract A micro-sprinkling hose has been a promising type of equipment for water-saving irrigation, due to the cheap, easy to lay and pack up when working. The performance of the micro-sprinkling hose depends on the kinetic energy in the process of field irrigation. The intensity of kinetic energy is determined by the droplet distribution of spraying water in the air. This paper aims to explore the droplet diameter distribution of the micro0sprinkling hose to find out the drop characteristics and the effect of the pressure and spraying angle on the droplet diameter distribution. Therefore, an indoor experiment aimed to explore the drop diameter distribution of micro-sprinkling hose with different pressures (20 kPa, 24 kPa, 28 kPa, and 32 kPa) and different spraying angles (20°, 30°, 40°, 50°, 60°, 70° and 80°) were conducted. The droplet characteristic parameters were measured and collected using a laser precipitation monitor (LPM). The results show that: (1) The diameter of single-hole spraying water droplets of micro-sprinkling hose increased with the increase of pressure, and the distribution range also increases. The diameter of single-hole spraying water droplets of micro-sprinkling hose increases first and then decreases with the increase of spraying angle. The peak value of the droplet diameter appears at the spraying angle of 40°. (2) The farther away from the ground, the larger the percentage of water droplets increased from 0.50 mm to 0.75-1.00 mm. The overall distribution range of water droplet diameter is 0–2.00 mm. The results clarified the droplet diameter distribution characteristics of the micro-sprinkling hose under different four pressures and seven spraying angles. The study has a guiding significance for the structure design of micro-sprinkling hose.