基于CFD动网格技术的三偏心蝶阀开启特性  

Opening characteristics of triple eccentric butterfly valve based on CFD moving grid technology

作　　者：何庆中 刘玉聪 赵献丹 刘佳 HE Qingzhong;LIU Yucong;ZHAO Xiandan;LIU Jia(School of Mechanical Engineering, Sichuan University of Science & Engineering, Sichuan, Zigong 643000,China)

机构地区：[1]四川轻化工大学机械工程学院

出　　处：《排灌机械工程学报》2019年第6期508-512,共5页Journal of Drainage and Irrigation Machinery Engineering

基　　金：2014年自贡市重点科技计划项目(第二批)(014JZ05);四川理工学院研究生创新基金资助项目(y2016014)

摘　　要：为了分析三偏心蝶阀在开启过程中涡流与时间的关系,采用Fluent软件提供的计算方法,建立了基于三偏心蝶阀的二维物理模型,编写不同时刻的UDF函数,利用动网格技术及用户自定义函数对三偏心蝶阀开启过程出现的涡街现象进行数值模拟,得到了开启后不同时刻下的涡流速度和涡流长度.结果表明:在三偏心蝶阀刚开启的瞬间,蝶阀的下流产生喉口效应,流体介质小开度下由于流阻较大,导致蝶阀的振动强烈,随着开度的增大,流阻急剧减小,蝶阀的振动逐渐减弱,导致三偏心蝶板边缘前后均产生强烈的涡流,下端出现了较明显的涡街效应,随着开启行程的增加,涡流速度不断减小,而涡流长度先增加后缓慢减小,最终消失.通过有限元分析法对蝶阀的流场进行了数值模拟,找到了涡街现象的形成和脱落的时间.此模拟为三偏心蝶阀设计、试验和使用提供了一种思路.In order to analyze the relationship between eddy current and time in the opening process of triple eccentric butterfly valve, a two-dimensional physical model based on triple eccentric butterfly valve was established by using the calculation method provided by Fluent software, and the UDF functions at different times were compiled. The eddy street phenomenon in the opening process of triple eccentric butterfly valve was analyzed by using dynamic grid technology and user-defined functions. Numerical simulation was carried out to obtain the vortex velocity and vortex length at different times after opening . The results show that the throat effect is produced in the down flow of the butterfly valve when the triple eccentric butterfly valve is just opened. The vibration of the butterfly valve is strong because of the large flow resistance under the small opening of the fluid medium. With the increase of the ope-ning, the flow resistance decreases sharply, and the vibration of the butterfly valve gradually weakens. As a result, strong eddy currents occur around the edge of the triple eccentric butterfly plate, and obvious vortex street effect appears at the lower end. With the increase of opening stroke, the eddy velocity decreases continuously, and the eddy length increases firstly, then slowly decreases, and finally disappears. The flow field of butterfly valve was simulated by finite element method, and the time of vortex street formation and shedding was found. This simulation provides a train of thought for the design, test and use of the triple eccentric butterfly valve.

关 键 词：三偏心蝶阀 启闭过程 卡门涡街 动网格 

分 类 号：TK7[动力工程及工程热物理—流体机械及工程]