Numerical Simulation and Validation of Droplet Deposition on Tomato Leaf Surface under Air-Assisted Spraying

Abstract

The interaction between the leaf and airflow directly influences droplet deposition on the leaf surface. This paper investigates the effect of this interaction on droplet deposition. A bidirectional fluid-structure coupling model was established using computational fluid dynamics (CFD) based on mechanical parameters and surface roughness of tomato leaves to simulate tomato leaf deposition under air-assisted spraying. Utilizing the model and considering air velocity, droplet size, and initial leaf inclination as experimental factors, a three-factor, three-level central composite design simulation and response surface analysis were conducted to examine the influence of each factor on the surface deposition amount of tomato leaves. The order of influence of each factor on the deposition amount is as follows: a quadratic regression model was established with the flow velocity having the greatest influence, followed by initial leaf inclination and then droplet size. The influence of each factor on the deposition distribution of the leaf surface was compared and studied separately. Airflow velocity significantly affected the deposition distribution of the leaf surface. Higher airflow velocities resulted in a lower proportion of deposition at the tip and a higher proportion at the base. The maximum relative errors of leaf deformation and deposition were 8.77% and 17.44%, respectively. The findings of this research can provide valuable insights for optimizing the working parameters of air-assisted atomizers.

Keywords

• air-assisted spraying
• numerical simulation
• fluid-solid coupling
• droplet deposition
• deposition distribution