摘要
采用离散相模型、标准k-ε湍流模型与Couple算法,应用计算流体力学软件Ansys Fluent,对气流辅助喷雾流场进行了三维数值模拟。研究气流辅助的防飘移机理,分析不同条件气流辅助喷雾对雾滴飘移的影响。计算结果表明:气流辅助通过改变自然气流运动方向,胁迫雾滴运动,可以明显减少雾滴的飘移量;风量越大,产生的飘移越小;气流方向与垂直方向成30°时,产生的雾滴飘移率最小;喷头越接近辅助气流,产生的飘移越小。自然风速小于5m/s时,辅助气流能够有效地防止雾滴飘移;自然风速大于5m/s时,雾滴飘移率大于40%。
Based on the discrete phase model(DPM),couple algorithm and standard k-ε turbulence model,a three-dimensional simulating model of air-assist spraying was developed with the software of Ansys Fluent.The drift-reduction theory and effect under different condition of air assist spraying were also fully analyzed with the developed model.The simulating results show that drift rate of droplets can be reduced effectively with the change of air flow direction through changing sediment trajectory of droplets.It also shows that air-assist spraying was more effective on drift-reduction with the increase of air volume,decrease of distance between outlet of air flow and nozzle and 30 degrees between air flow direction and nozzle.The comparison of simulating results under different national wind speed indicates that air-assist spraying can effectively prevent and reduce droplets drift when wind speed is less than 5m/s.But the drift rate of droplets can exceed 40% when wind speed is over 5m/s.
出处
《农机化研究》
北大核心
2012年第9期44-48,共5页
Journal of Agricultural Mechanization Research
基金
国家"863"高技术研究发展计划项目(2010AA101403)
国际科技合作计划资助项目(2010DFA71310)
关键词
气流辅助
离散相模型
防飘移
数值模拟
air-assist spraying
DPM
drift reduction
three dimensional
numerical simulation
