Simulation of sprinkler water distribution with droplet dynamics and evaporation

Based on the model of droplet dynamics and evaporation, the simulation method of droplet flight was put forward under the wind condition. Software of simulating sprinkler water distribution was developed by Visual Basic 6.0. With the radial water distribution data of single sprinkler, the software could simulate water distribution of single sprinkler or sprinkler irrigation system and calculate combined application rate, uniformity coefficient and evaporation loss rate of sprinkler irrigation system. Taking the sprinkler 9708A as example, radial water distribution of single sprinkler and water distribution of sprinkler irrigation system with the combined spacings of 14 m × 14 m and 14 m × 12 m were simulated and compared with the measured values under the pressures of 0.20, 0.25 and 0.30 MPa. The results showed that the simulated values of radial water distribution of single sprinkler had the same tendency as the measured values on the whole, the relative error between simulated and measured values of flow rate ranging from 0.83% to 8.01%, that of the uniformity coefficient (Cu) ranging from 0.44% to 7.77%, and the simulated evaporation loss rate ranging from 0.51% to 1.75%. Several cases of sprinkler water distribution with different combined spacing were compared by using the developed software and other software. The relative error of the simulated values of Cu varied from 0.11% to 2.44%.