Yisheng Zhang, Delan Zhu

　　College of Water Resources and Architectural Engineering,North A&F University, Yangling Shaanxi Province, China

　　Reducing the working pressure of the sprinkler irrigation machine can decrease the irrigation operating cost effectively, as a part of the machine, lower working pressure of sprinkler is essential to sprinkler irrigation. In order to develop a new type of the fixed spray plate sprinkler (FSPS) which working pressure is lower than 100kPa, the FSPS with different groove characters has been made, and Data Logging Rain Gauges and Two-Dimensional Video Disdrometer (2DVD) were applied to measure its water application rate and droplet diameter in radial direction of the single channel. The variation of droplet diameters and the changes of water discharge ratio with the  jet angle and dimension of the groove was anaysis, the optimum characters of the jet angle was determined with the goal of improving vice-channle based on ballistic theory, and the dimension of the groove was caculated aiming for decreasing the peak water application. And the software for calculating the arrangement of the sprinkler structure was developed according to the water distribution of optimizing groove. The result shows that the combination of major and minor channel can reduce the peak water application effectively, the water discharge ratio decreas at an exponential function with ratio of the entrance length of major and minor channel. The maximum droplet diameter decreased with the increasing of the jet angle at the same working pressure, the major jet angle range from 31°to 36°, the jet distance can achieve the maximum. When the jet angle of major and  minor channel is 33°and 0°respectively, the length of the channel is 5mm, the ratio of the entrance length of major and minor channel is 0.179, the arrangement angle is 36°, the fixed spray plate sprinkler present trapezoidal water distribution at moving condition with lower working pressure(lower than 100kPa), it is benefit to minimizing cost of operation of the moving sprinkler irrigation system