压力旋流喷头雾化性能的仿真

为了提高喷雾质量，提高农药的使用效率，用CFD商用软件FLUENT对雾化喷头在农药雾化时的流场进行数值模拟。利用Eulerian—Lagrangian双流体模型来模拟气液两相流动。模拟结果表明：药液雾化形状为中空锥形结构，大部分液滴速度大于1．12m／s；雾化液滴的体积中值直径（NMD）在50～100Mm之间，数量中值直径（NMD）在30～70Mm之间，适用于苗期或者前期的叶片植物农药的喷洒；压差在2．0MPa以下时，雾化均匀度（DR）大于0．67，雾化性能良好，所以此类型喷头选用的喷雾压差应小于2．0MPa。喷头仿真预测了雾化喷头的微粒化性能，为高效低喷量喷雾的研究提供一定的依据。

Simulation of Spray Characteristics of Pressure-swirl Nozzle

To improve the quality of spray and efficiency in the use of pesticides,atomization flows of pesticides was numerically simulated by CFD.The mixed Eulerian-Lagrangian model was used to simulate the gas-liquid two-phase flow.Simulation results showed that liquid pesticides had cone shape for the hollow structure when atomizing,most droplets velocity was above 1.12 m/s;The volume median diameter(VMD) was between 50 μm and 100 μm,number median diameter(NMD) was between 30 μm and 70 μm.The droplet was fit for leaf plant on seeding stage or prophase.When the working pressure difference was under 2.0 MPa,DR was above 0.67,atomization had excellent performance,so the pressure difference under 2.0 MPa should be chosen when this type of nozzle was used to spray pesticide. Numerically simulation predicts particulate performances of the nozzle,the results provided theoretical foundation for studying the flows of sprays with high efficiency and low volume.