The Research Of The Hydraulic Performance Of Sprinkler

Sprinkler nozzle is the most important component of an sprinkler irrigation system, the hydraulic characteristic of sprinkler nozzle determines the overall effect of irrigation. In this research experiments aiming at the hydraulic characteristic parameters of two commonly used big size sprinklers(PYC50 and HY50) were done, and the hydraulic changing regularity under different effect factors were analyzed. On this basis, a comparison of hydraulic parameters between the two big size sprinklers were made, to provide reference for the selection of spray gun.The major findings are:(1)Through the hydraulic characteristic test of two big size sprinkler(operating pressure,flow rate, application rate), the water distribution of the two sprinklers under different pressures were achieved. Through the comparison between PYC50 and HY50, it is found that HY50 shows a better performance in spray range and flow rate, meaning a larger spraying control area and higher water use efficiency. PYC50 shows a lower application rate and has a better adaptability and can be oriented to more kinds of crops and soil type. The variation of water distribution was analyzed through structure of the two sprinklers.(2)The radial droplet diameter and corresponding velocity under operating pressure of0.15,0.25,0.35 and 0.45 MPa and under different nozzles for PYC50 and HY50 were captured using a 2D-video-distrometer. The effects of operating pressure, nozzle size and sprinkler type on radial droplet diameter were analyzed. The relationship between droplet size and radial distance of the two kinds of spray gun was fitted, showing an exponential function between them. The radial droplet size with the same nozzle size and operating pressure of the two sprinkler was compared and the caused that leading to variance was analyzed. The drop size of HY50 at the end of spray area was always larger than PYC50,showing higher impact strength to crop and surface soil.(3) The distribution of kinetic energy was obtained through the droplet spectrum achieved by 2D-video-distrometer, such as the droplet size and droplet velocity. The relationship between kinetic energy of single drop and droplet size, unit volume kineticenergy and distance to the sprinkler were fitted. The effects of operating pressure and nozzle size on the distribution of kinetic energy was analyzed. By comparing the difference of radial kinetic energy between PYC50 and HY50, it is found that the overall trend look the same,besides that the kinetic energy of HY50 under each measuring point is higher than that of PYC50, signifying a higher erode ability potential.(4) The combination of water distribution and kinetic energy distribution were achieved for both PYC50 and HY50 big size sprinklers, and the combination spacing was set as 1.0R, 1.2R and 1.4R, respectively. The uniformity coefficients of water distribution and kinetic energy distribution were obtained with the square layout under various combination spacing. The effect of combination spacing and operating pressure on uniformity coefficients were analyzed and the results showed that PYC50 shows better performance compared to HY50 under the same working condition.