Design And Experiment Of Slant Breezy Sprayer Of Strawberry For Elevated Cultivation In Greenhouse

In recent years,as a new type of cultivation method with labour-saving and high income,the elevated cultivation of strawberry has been vigorously promoted due to its many advantages such as cleanness and labour-saving.However,the existing application equipment cannot meet the requirements of efficient and uniform spraying of overhead strawberry.Therefore,in order to meet the requirements of mechanized pesticide application for greenhouse elevated strawberries,this paper designs and develops a tilting breeze application machine for overhead strawberry,which provided technical and equipment support for realizing high-efficiency,low-volume and non-destructive mechanized pesticide application of elevated strawberries.The research content and work of this paper are as follows:(1)Based on the investigation of the elevated cultivation environment of strawberry in greenhouse,the prevention and control of strawberry diseases and insect pests and the characteristics of strawberry plants.On this basis,the overall design requirements of the pesticide application machine are analyzed and obtained,and a special overall design scheme of four rows of spray cylinders on both sides,centered,tilted and slightly atomized,is proposed,and the manufacture of the whole machine is completed.(2)Using CFD simulation technology,the deposition movement of droplet population under the action of auxiliary airflow was simulated by setting different roll angles and nozzle wind speeds.In addition,an auxiliary airflow field measurement test was carried out,and the distribution of wind speed along the axial and radial directions of the auxiliary airflow field was measured.Based on the above simulation tests and further simplified analysis of tilting breeze,a droplet deposition model and a droplet motion trajectory mathematical model of spray height-angle-sprinkling width are established,which provide theoretical basis for optimization of tilting breeze spray parameters and intelligent adaptive spray control algorithm.(3)The mechanical properties of strawberry petiole were studied through the biological characteristics test of elevated strawberry,and the relationship between the bending deflection and elastic modulus of petiole and the size of petiole was analyzed.Under the conditions of different roll angles and wind speeds,the wind-induced vibration motion test of strawberry leaf petiole was carried out,the wind-induced vibration motion characteristics and morphological changes of leaf petiole under different conditions were analyzed,further research on inflorescence damage caused by wind speed was carried out,and the test results were statistically analyzed,which provided theoretical reference for further spray test,improvement of spray effect and optimization of application operation parameters.(4)The feasibility of the whole machine design scheme and the rationality of the optimization of system structural parameters are verified through the field spray test of the prototype for overhead strawberries in the greenhouse.The distribution law of droplets and the application effect under different roll angles and wind speeds are obtained.According to the test results,considering deposition of droplets,distribution uniformity and inflorescence non-destructiveness,the application effect is determined to be the best under 6 ~ 8m/s breeze speed and 30°roll angle,and the previous simulation results and wind-induced motion tests are verified.