A Spraying Model of Non-atomizing Sprinkler based on Jet Fragmentation

Abstract

This work is devoted to the development of a new model for the non-atomizing sprinkler irrigation jet, for calculating the trajectories and landing positions of water droplets. The novelty of the proposed model is that the secondary breakup of the droplets can be calculated during the spraying process. For irrigation jet with a second wind-induced breakup regime, the model is optimized based on the ballistic theory by considering the secondary breakup of droplets and the jet breakup length. The wave-breaking model is used to determine the secondary breakup of the droplets. The output of this model is the water application rate that is calculated by using the cumulative volume of droplets along the radial spraying direction. A comparison of the results obtained using the proposed model with experimental data is conducted to verify the accuracy and reliability of the proposed model. The results show a good agreement of the peak water application rate between the optimized model and the experimental data, with an average error ranging within 6%. The droplets in the front spraying area usually have a diameter of 0-2 mm. This is computed by using the droplet secondary breakup sub-model, resulting in a considerably improved accuracy of the optimized model in the prediction of the water application rate of a sprinkler.

Keywords

• sprinkler irrigation
• droplets movement model
• ballistic theory
• secondary droplets breakup
• jet breakup length