CFD modelling to analyze the droplets deposition behavior on vibrating rice leaves

Abstract

The external airflow and the auxiliary airflow of air-assisted application make the leaves vibrate during operation. Such vibration affects the deposition behavior of spray droplets on the leaves. In this study, A multiphase flow computational fluid dynamics (CFD) simulation model was developed and validated. Dynamic process simulations were performed using a validated CFD simulation model, which set spray droplet particle size, impact velocity, leaf tilt angle, and rotational angular velocity as variables. The simulation test results revealed that: the droplet velocity and leaf tilt angle were crucial factors affecting the deposition behavior of droplet adhesion, bouncing, and splitting; compared to static leaves, leaf vibration did not impact the deposition behavior selection of droplets under the influence of 5–10 m/s air velocity. However, the increase of leaves rotation angular velocity increased the droplet spreading to a certain degree. The CFD model validation test results conform with the simulation results. More specifically, the relative error of the longitudinal spreading factor was within 10% and the relative error of the spray droplet spreading diameter was within 20%. This study provides CFD models that can be used for the study of spray droplet deposition behavior on the surface of vibrating rice leaves, thereby providing a reference for rice plant protection and the selection of pesticide application parameters.