Numerical Simulate Of Interior Flow-field About Plant Protective Nozzle

Plant protective nozzle as a terminal element for atomizer to achieve spraying plays a very important role in spray device. The pros and cons of its performance will directly affect the quality of the system. However, the current design theory of plant protective nozzle is not yet mature, with few excellent models. The present study on the nozzle mainly concentrates on the experimental research and theoretical analysis. Through experiments, effects of structural parameters of the nozzle on its performance are got to revise structural parameters. This design method that amends the structural parameters through experiment consumes a significant amount of resources and manpower, and has longer design cycle.With the development of the computer technology and computational fluid dynamics, research of the three-dimensional flow field develops rapidly, and has become a hot focus at this stage of the study. The CFD technology is applied to carry out the numerical calculation in flow field, observe and analyze the internal flow structure, predicate the nozzle performance, optimize the structure of the nozzle design and improve the design theory and design methods.This paper adopts the standard k-εturbulence model, and uses Pro / E three-dimensional modeling software to perform physical modeling and the physics shape was meshed by unstructured grids; applies finite element method, variational principle and weighted residual method to perform discretization. The numerical calculation and analysis in the internal flow field of the vortex type nozzle obtains such internal characteristics as velocity field and pressure field. The numerical simulation, and analysis of effects of different nozzle outlet axial size, different angle of the core-cone-shape and different nozzle outlet diameter on atomizer performance make the following conclusions:(1)The shape of vortex chamber take important role on side-entry hollow cone nozzle, When change the working and structure parameter, the flow performance of inner flow field will be changed at same time; (2)the nozzle outlet axial size will affect direction of the outlet velocity, then take influence on spray cone-shape angle;(3) After simulate we know the nozzle have direct ratio between inlet-plane-centre velocity and work pressure.