Multi-physical Coupling Model For Consecutive Impact Of Pesticide Droplets Onto Tea Leaf Of Shu-Cha Zao

Tea plays an important role in China’s daily economic production and export.However,the excessive pesticide residues in tea has been the greatest problem causing pollution in China.It is well known that excessive pesticide residues not only affects tea quality,does harm to the health of consumers,but also reduces the competitiveness of tea export.Now this problem has restricted the development of China’s tea industrialization and internationalization seriously.Therefore,in order to reduce pesticide residues and improve pesticide utilization,it is of great significance to research the methods to improve pesticide spraying efficiency in the process of tea growth.Traditional experimental methods mostly investigate the effect of pesticide spraying from the macro perspective of measuring anti drift,distribution uniformity,penetration ability and target coverage,but these methods can not capture the micro dynamic behavior of droplets on the leaf surface.Based on the above problem,this thesis selects Shu-Cha Zao leaves as the target:1)introduces the theory of mechanical structure,and constructs the geometric models of Shu-Cha Zao leaves under three growth postures(horizontal,curved and vertical)by measuring the geometric dimensions and structural characteristic parameters of the leaves and using feature modeling technology;2)in order to explore the influence of the two-phase fluid solid fluctuation load generated by the continuous impact of droplets on the leaf behavior evolution law of droplets on the leaf surface,a multi pesticide droplet continuous impact Shu-Cha Zao leaf performance parameter test platform is designed and built.3)High speed photography technology and vision based vibration measurement technology are used to obtain the time delay of pesticide droplets impacting tea leaves under different nozzle aperture and jet speed,And the micro buffeting performance parameters of the leaves after being impacted by the droplets,and finally realize the construction of the three-dimensional multi physical coupling accurate calculation model of the continuous impact of pesticide droplets on the leaf of Shu-Cha Zao.This computation model can help us understand the micro flow law and mechanism of pesticide droplets on tea leaves and reveal the mechanism of the evolution of sputter /rebound / deposition on the leaf surfaces.It provides a scientific theoretical basis for optimizing the design of related plant protection spray heads,selecting the spray conditions of tea plants and reducing pesticide residues in tea leaves.The research results can be used for reference in the application of feature modeling technology and visual measurement technology in agriculture.It has theoretical significance for developing precision spraying technology,and has practical value for improving the deposition efficiency of pesticide spray in tea plant.