中小型真空注型机动态混合器混合性能的研究

发布时间：2018-06-01 12:16

本文选题：真空注型机 + 动网格　；参考：《西安理工大学》2017年硕士论文

【摘要】：真空浇注(VC)技术是快速成型技术最广泛的应用之一,基于此技术的真空注型机是一种将不同组分的溶液混合并浇注固化成产品的设备,这种设备可以实现多品种、小批量、非金属零件的高效率、敏捷化生产,能够满足企业生产需要,使其在激烈的市场竞争中占据有利地位,受到市场的青睐。其中,溶液的混合效果直接关乎产品质量,对注型设备内部混合器的研究也越来越受到人们的重视。本文基于计算流体力学技术,针对中小型真空注型机内部的混合装置进行了相关研究。借鉴国内外研究经验,设计了一款能够生产非金属制品的中小型真空注型机,并据此提出了与该设备匹配且实现溶液按比例混合的新型动态混合器。建立注型机浇注舱与动态混合器的有限元模型,应用FLUENT软件中的S2S辐射与对流模型对浇注舱内的热场进行了分析,选用动网格模型、Mixture多相流模型、RNGk-ε湍流模型及PISO算法对在此温度条件下工作的动态混合器内部流场进行了宏观分析,并在此基础上,实现了对混合器结构一定程度的改进;另外,分别从改变预混合器出口位置、叶片数量和叶轮转速等方面对混合器的混合性能进行了研究;最后,通过采用对混合浇注后制品的观察和力学性能测量两种不同的检验方式,评测了混合器的混合性能。研究结果表明预混合管道出口位置不同时,混合器混合效果不同;当叶片数量为16时,混合效果最理想;模拟还表明,增加叶轮旋转速度对混合效果作用明显,但是达到一定转速后,混合效果趋于稳定;在此基础上,通过液体质点运动矢量图、速度流线图和湍动强度分布云图,分析了加速溶液混合均匀的主要因素是叶轮二次剪切和混合器中运动部件对流场的湍动作用,选用环氧树脂(E51)与固化剂进行混合并浇注成型,实验结果表明该混合器混合性能可靠。以上研究结果,对动态混合器的设计和分析具有一定的参考意义。
[Abstract]:The vacuum casting technology is one of the most extensive applications of rapid prototyping technology. The vacuum casting machine based on this technology is a kind of equipment for mixing different components of solutions and solidifying them into products. The high efficiency and agile production of non-metal parts can meet the production needs of enterprises and make them occupy a favorable position in the fierce market competition and be favored by the market. Among them, the mixing effect of solution is directly related to product quality, and the research on internal mixer of injection equipment has been paid more and more attention. Based on computational fluid dynamics (CFD) technology, the mixing device of medium and small vacuum injection machine is studied in this paper. Based on the domestic and foreign research experience, a small and medium-sized vacuum injection machine was designed to produce non-metal products. Based on this, a new type of dynamic mixer was put forward, which matched the equipment and realized the proportional mixing of solution. The finite element model of the pouring tank and dynamic mixer of the pouring machine is established. The heat field in the pouring tank is analyzed by using the S2S radiation and convection model in FLUENT software. RNGk- 蔚 turbulence model and PISO algorithm are used to macroscopically analyze the internal flow field of the dynamic mixer working at this temperature. On the basis of this, the structure of the mixer is improved to a certain extent. The mixing performance of the mixer was studied by changing the outlet position of the premixer, the number of blades and the speed of the impeller, etc. Finally, two different inspection methods, the observation of the products after mixing and the measurement of the mechanical properties, were adopted. The mixing performance of the mixer is evaluated. The results show that the mixing effect of the mixer is different when the outlet position of the pre-mixed pipe is different, the mixing effect is the best when the number of blades is 16:00, and the simulation also shows that the mixing effect is obvious when the rotating speed of the impeller is increased. However, the mixing effect tends to be stable after a certain rotational speed is achieved. On this basis, through the vector diagram of liquid particle motion, the velocity streamline diagram and the turbulent intensity distribution cloud diagram, The main factors of accelerating the mixing uniformity of the solution are the secondary shear of impeller and the turbulent movement of the moving parts in the mixer. The epoxy resin E51) is mixed with the curing agent and molded. The experimental results show that the mixing performance of the mixer is reliable. The above results have some reference significance for the design and analysis of dynamic mixer.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH16

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