转盘表面黏性薄液膜稳态流动特性数值模拟

发布时间：2018-03-15 12:10

  本文选题：流体力学　切入点：模型　出处：《化工学报》2017年06期 　论文类型：期刊论文

【摘要】：转盘表面薄膜流广泛存在于转盘反应器、造粒和分子蒸馏等化工领域,其流动特性对造粒、反应以及热质传递具有重要影响。建立了稳态薄膜流动特性理论模型,并对比实验数据与数值模拟结果,研究了等效Froude数Fr、量纲1特征厚度与长度比值ε和浇注尺寸r_i对薄膜厚度分布的影响,导出了水跃和同步区半径模型并通过实验验证。结果表明:等效Froude数Fr不会对薄膜厚度分布产生明显影响;量纲1ε和浇注尺寸r_i是水跃发生与否的决定条件,增大ε或缩小r_i有助于水跃出现,水跃半径稳定于r=0.85;平均径向速度呈典型三分区特征,缩小浇注尺寸r_i将引起浇注区范围加大而加速区范围显著缩小,导致薄膜无明显加速现象而直接进入同步区,但同步区半径维持在r=1.53。研究结果为转盘反应器以及离心粒化器等的设计与优化提供了可借鉴的理论与应用基础。
[Abstract]:Thin film flow on the surface of rotating disk is widely used in chemical industry such as rotating disk reactor, granulation and molecular distillation. Its flow characteristics have important influence on granulation, reaction and heat and mass transfer. A theoretical model of steady film flow characteristics is established. Compared with experimental data and numerical simulation results, the effects of equivalent Froude number Fri, dimensionality 1 characteristic thickness to length ratio 蔚 and pouring size RMI on film thickness distribution were studied. The radius models of water jump and synchronous zone are derived and verified by experiments. The results show that the equivalent Froude number Fr has no obvious effect on the thickness distribution of the film, and dimension 1 蔚 and pouring size r I are the determining conditions for the occurrence of water jump. Increasing 蔚 or reducing rSII is helpful to the emergence of water jump, and the radius of hydraulic jump is stable at 0.85. The average radial velocity is characterized by three typical zones. The results of the study provide a theoretical and practical basis for the design and optimization of turntable reactors and centrifugal granulators.
【作者单位】： 江南大学机械工程学院江苏省食品先进制造装备技术重点实验室;南京工业大学江苏省过程强化与新能源装备技术重点实验室;
【基金】：国家自然科学基金项目(51606086,51406078)~~
【分类号】：TQ021.1
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本文编号：1615968