Cfd Simulation And Experiment Of Air-Velocity Distribution Of Air-Assisted Spray Of Orchard

Air-assisted spray is the new technology arisen recently in the field of plant protection equipment.Its special advantages as follows:saving labor and durg, low cost, and being not strict to the sorts of drug and weather condition,which have made this new technology walk in the first rank in field of plant protection equipment. Compared with developed country in the field, we still have some distance, it’s mainly reflected in the lower efficiency and utilization of pesticide application, so developing plant protection equipment actively and studying spraying technology have urgent priority.In this paper,numerical simulation of air-velocity of fan was simulated. A steady three-dimensional computational fluid Dynamics (CFD) model was developed using software FLUENT.The main research contents and conclusions are listed as follows:(1) A physical and turbulence mathematics model of air-velocity of fan was established and simulated using Computational Fluid Dynamics (CFD) software FLUENT with standard k-ε model and appropriated boundary condition during numerical simulation of air-velocity distribution. CFD model of numerical simulation of air-velocity distribution of air-assisted spray was created. The simulated results showed that inlet velocity had little effect on the distribution pattern, but different vetical planes from the fan had a great effect on it. Double fan flow field of significant effect on each other. In the region from one meter to three meters from the fan center, the velocities of the center region were lower than the both sides. But in the region from three meters to five meters from the fan center,the air-velocity distribution of double fan was uniform.(2) ShenLi SF-4of axial flow fan of air-velocity field was measured. Experiment showed that the velocity field along the axial line of fan decreased rapidly, the velocities of under the centerline of fan were higher than on the centerline, and the right air-velocities were higher than the left ones. Comparison of simulated and experiment values at vertical planes at three meters from the fan of single and double fans,it was found that the simulated and experiment values were uniform. The correlation determination(R2)of single and double fans were0.9382and0.9387respectively.(3) The velocities of canopy of apple tree were measured at different inlet velocities and different distance. Experiment showed that the velocity decreased rapidly with the depth of canopy and the middle region is higher than the edge region. With the increase of distance, the velocities of the right of canopy of apple tree become higher and higher, but the left reduce.