射流混药装置面积比对混药均匀性的影响  

Effect of Area Ratio on Mixing Homogeneity in Jet-mixing Apparatus

作　　者：邱白晶[1] 徐溪超[1] 邓斌[1] 杨宁[1] 姜国微[1] 吴春笃[1] 

机构地区：[1]江苏大学现代农业装备与技术省部共建教育部重点实验室,镇江212013

出　　处：《农业机械学报》2011年第10期95-100,共6页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家高技术研究发展计划(863计划)资助项目(2008AA100905;2006AA10A305-3);国家自然科学基金资助项目(30571240);江苏省属高校自然科学重大基础研究项目(10KJA470007);高等学校博士学科点专项科研基金资助项目(20093227110008)

摘　　要：以探索农药和水混合后混药均匀性表征的数值计算途径为目标,确定了射流混药装置混药质量分数分布场数值模拟方案,采用CFD软件Fluent对射流混药装置混药质量分数分布场进行了数值计算。引入离析度概念来定量评价射流混药装置中农药和水的混合均匀程度,离析度降为0.05视为药水混合均匀。当面积比m∈[2.564,.00]时,随面积比的增大,最小混合距离下降,但最小混合距离的下降受混药效率的制约。综合考虑,面积比m=3.06的射流混药装置混药性能高于面积比m=2.56、4.00的射流混药装置。混合管中最大湍流强度均下降14.96%进入扩散混合区,扩散混合区所在的坐标区间为:X∈([-13.85m+111.37)mm,116.5 mm]。因此,在实验测量射流混药装置混药后的农药质量分数时,应按照扩散混合区所在的坐标区间,针对不同面积比合理布置质量分数测量点。Aimed at homogeneity principle of water mix with pesticide in the jet-mixing apparatus,a mathematical model for solving the interior concentration field was established,CFD software called Fluent was used to calculate the field.Time-average mass fraction of pesticide was obtained.Intensity of segregation was introduced to quantitative evaluate the mix degree of water and pesticide.The water was mixed with pesticide uniformly when intensity of segregation was 0.05.As the increasing of area ratio,the shortest mixing distance decreased with the area ratio m∈[2.56,4.00].The mixing performance of jet-apparatus with m=3.06 was better than the jet-mixing apparatus with m=2.56 and m=4.00.The diffusive mixing zone appeared after the maximum turbulent intensity average rate decreased by 14.96%.And the coordinate interval was X∈[（-13.85m＋111.37） mm,116.5 mm].Therefor,when measure the concentration in jet-mixing apparatus by experiment,it should according the coordinate interval and area ratio to choose the appreciate concentration measurement point.

关 键 词：混药装置 面积比 离析度 计算流体动力学 

分 类 号：S49[农业科学—植物保护]