农用超声雾化换能器参数优化设计与试验  

Parameter optimization design and experiment of agricultural ultrasonic atomization transducer

作　　者：张建桃[1] 李晟华[2] 文晟[2] 兰玉彬[2] 廖贻泳 张铁民[2] 

机构地区：[1]华南农业大学数学与信息学院,广州510642 [2]华南农业大学工程学院,广州510642

出　　处：《农业工程学报》2015年第12期8-15,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：广东省自然科学基金(S2013010013747);教育部高等学校博士学科点专项科研基金(20134404120020)

摘　　要：为解决超声雾化换能器用于超低量喷雾时雾化量少、换能器结构复杂等问题,根据超声雾化换能器的工作原理和农药喷施对换能器提出的雾化要求,设计了一种农用超声雾化换能器。首先利用ANSYS参数化设计语言建立换能器超声振子的参数化模型;然后对其进行尺寸参数优化,在设定的雾滴体积中径3~5μm范围内,使雾化量达到最大;最后根据优化结果制作样机,进行相关试验测试。试验结果表明,当施加峰-峰值为100 V的交流正弦电压时,超声雾化换能器最大雾化量从1.20提高到1.29 g/min,相比优化前提高了7.5%,93%的雾滴颗粒直径分布在设定的3~5μm范围内,并且实测的换能器谐振频率与仿真结果的误差为5.9%。研究结果为农用超声雾化换能器结构优化设计和雾化量的提高提供参考。In order to solve the problems when ultrasonic atomization transducer was used for ultra-low-volume spraying pesticides, i.e. the atomization flow was little and the transducer＇s structure was complex, this paper presented a new structure of agricultural ultrasonic atomization transducer based on the atomization requirements proposed by the working principle of ultrasonic atomization transducer and agricultural pesticide spraying. The transducer mainly consisted of a venturi tube, a cylindrical square-cavity, an ultrasonic vibrator, a rubber washer and a flange cover. When the high-frequency alternating current （AC） voltage was applied on the ultrasonic vibrator, liquid was atomized. In the meantime, the circumscribed air pump formed the air vortex in the square-cavity, which would drive the droplet to rotate and move upward, prevent the spread of droplet and avoid attaching on the inner wall of the vessel. Firstly, the parametric model of the ultrasonic vibrator was established and then optimized with ANSYS parametric design language （APDL） to control the droplet diameter of the transducer within the setting range and maximize the atomization flow. In the atomization process, we chose the electrode diameter and the thickness of the ultrasonic vibrator as the design variables, the vibration amplitude of the ultrasonic vibrator as the objective function, and the driving frequency as the constraint condition. Secondly, penalty function was used to solve the optimization problem with inequality constraints. Meanwhile, the modal assurance criteria （MAC） were adopted to recognize the target modals intelligently by ANSYS finite element software. If the value of MAC was closed to 1, the target model was similar to the reference model. This indicated that the vibration along the axial direction was concentrated on the surface of the ultrasonic vibrator and the vibration amplitude was larger than other models. Thirdly, a prototype built based on the optimization results was manufactured to conduct the atomiz

关 键 词：喷雾 有限元法 优化 结构设计 超低量喷雾 

分 类 号：S224.3[农业科学—农业机械化工程]