Abstract:Abstract: The kinetic energy of sprinkler spraying is an important factor to evaluate sprinkler hydraulic performance, and has a great significance to study soil and water conservation. The kinetic energy of sprinkler spraying mainly includes the droplet kinetic energy, the kinetic energy per unit volume, the kinetic energy intensity and the uniformity coefficient of kinetic energy intensity. All of them are closely related to the hydraulic parameters of sprinkler. The hydraulic parameters contain the water distribution, the droplet diameter and the droplet velocity. To study the kinetic energy distribution of PXH, PXH10 sprinkler hydraulic parameters were tested under the no wind condition, with the operating pressure of 0.15, 0.20, 0.25, 0.30 and 0.35 MPa, respectively. The single sprinkler water distribution was measured by catch cans. The catch cans were placed on the testing stand with a spacing of 2 m × 2 m. The laser precipitation monitor (LPM) was used to measure the droplet diameter and velocity. The results showed that the kinetic energy of sprinkler spraying distribution of PXH was different from the other types of sprinklers. The droplet kinetic energy increased with the increase of the droplet diameter. The relationship between droplet kinetic energy and droplet diameter of PXH was indicated by the power function model. The correlation coefficients for the model were up to 0.9 in different pressures. It increased by an average of 20% compared with the other models which were used to show the droplet kinetic energy distribution of PXH. Under different pressures, both the droplet kinetic energy and the kinetic energy per unit volume reached a maximum at the end of the spraying wetted radius. When the pressure increased, the maximum of the kinetic energy per unit volume decreased. The kinetic energy per unit volume increased linearly with the distance from the sprinkler increasing. There were proportional relationships between kinetic energy per unit volume and operating pressures. The proportional function model, which was more appropriate than the exponential function model, could be used to express the distribution of the kinetic energy per unit volume for PXH. The kinetic energy intensity was greatly affected by the water distribution and the kinetic energy per unit volume. The kinetic energy intensity decreased with the operating pressure increasing at the same location. Under the pressure of 0.15, 0.20, 0.25, 0.30 and 0.35 MPa, the maximum kinetic energy intensity of PXH emerged at the distance of 8, 6, 7, 7 and 8 m, respectively. However, there was little difference between these maximum kinetic energy intensity values. Moreover, the kinetic energy intensity gradually increased with the distance from the sprinkler and rapidly decreased at the end of the sprinkler wetted radius. Under different pressures, uniformity coefficients of kinetic energy intensity about the rectangle combination spacing of PXH were simulated by MATLAB. The rectangle combination spacings were 1.0, 1.1, 1.2, 1.3, 1.4 times of the spraying wetted radius of PXH. The simulated results showed that under the operating pressure of 0.15, 0.20, 0.25, 0.30 and 0.35 MPa, the optimum combination spacings were 1.2, 1.0, 1.1, 1.0 and 1.1 times of the spraying wetted radius, respectively, and the uniformity coefficients of kinetic energy intensity were 56.6%, 71.1%, 76.2%, 77.2% and 72.9%, respectively. The results provide certain academic value for studying the sprinkler external spraying characteristics, and optimizing the sprinkler structure and irrigation system.