气动无针注射器喷嘴射流的数值模拟  

Numerical simulation of the jet flow from pneumatic needle-free injector nozzle

作　　者：刘仪 姜克建 LIU Yi;JIANG Kejian(School of Mechanical Engineering and Automation,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学机械与自动控制学院,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2022年第3期389-396,共8页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：浙江理工大学科研启动基金项目(11132932619106)。

摘　　要：为研究兽用气动无针注射器的喷嘴结构对射流形态、轴向喷射速度和动压的影响,利用计算流体动力学工具对淹没和非淹没两种实验工况下的高压射流进行数值模拟。在淹没环境中,采用Standard k-ε湍流模型,对平顶型、锥型和锥直型三种典型喷嘴的射流流场特性进行分析;在非淹没环境中,采用Standard k-ε湍流模型和VOF模型,对不同几何参数锥直型喷嘴的射流流场进行模拟分析。结果表明:在淹没环境中,锥直型喷嘴能够得到可控性较好且速度更高的射流;在非淹没环境中,当喷嘴直径为0.25 mm、收缩段长度为5 mm时,随着收缩角的增大,射流轴向速度先增大后减小,并在收缩角为30°时达到最大值;长径比为3的圆柱段能够较好聚集加速射流;入口压力为31 MPa的锥直型喷嘴产生的射流滞止压强能够满足兽用无针注射的要求,其滞止压强最大值位于以喷嘴中心轴线为圆心,半径0.06~0.07 mm的圆周内。该研究对无针注射器微型喷嘴的性能评估和优化设计有一定的参考意义。In order to investigate the influence of the nozzle structure of pneumatic needle-free injector on the jet flow shape, axial jet velocity and dynamic pressure, the numerical simulation was performed on high pressure jet under submerged experimental condition and non-submerged experimental condition using computational fluid dynamics tools. In the submerged environment, the jet flow field characteristics of three typical nozzles(the flat-top, conical and cone-straight type) were analyzed using Standard k-ε turbulence model. In the non-submerged environment, the numerical simulation was performed on the jet flow field of cone-straight type nozzle with different geometrical parameters using k-ε turbulence model and VOF model. The results show that the cone-straight nozzle can obtain a better controllable and higher velocity jet in the submerged environment. In the non-submerged environment, when the diameter of the nozzle is 0.25 mm and the length of the contraction section is 5 mm, the axial velocity of the jet increases first and then decreases with the increase of the contraction angle, and it reaches the maximum value when the contraction angle is 30°;the cylindrical section with length-width ratio of 3 can better gather the accelerating jet;the jet flow stagnation pressure generated by the cone-straight nozzle with an inlet pressure of 31 MPa can meet the requirements of the needle-free injection for veterinary use. The maximum stagnation pressure of the jet is located within a circle with the nozzle central axis as the center and a radius of 0.06~0.07 mm. The research results have a certain reference value for the performance evaluation and optimization design of the needle-free injector micro-nozzle.

关 键 词：无针注射 高压水射流 淹没射流 非淹没射流 喷嘴结构 数值模拟 

分 类 号：TH137[机械工程—机械制造及自动化] TH16