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题名	镜像流体法模拟斜叶桨搅拌槽
作者	张超
学位类别	硕士
答辩日期	2008-05-29
授予单位	中国科学院过程工程研究所
授予地点	过程工程研究所
导师	禹耕之
关键词	镜像流体法 搅拌 斜叶桨 数值模拟
其他题名	Application of Mirror Fluid Method in numerical simulation of Pitched Blade Turbine
学位专业	化学工程
中文摘要	由于具有良好的轴流性能，斜叶桨常用于涉及固体悬浮操作的各种搅拌反应器中。但斜叶桨的几何结构复杂，桨叶面与坐标轴斜交，对其进行数值模拟难度较大，现有计算方法在数值模拟过程中存在种种不足。本文尝试采用镜像流体方法处理斜叶桨，其基本思想是利用固体区域内的假想流体与真实流体区域关于界面的镜像关系，在固定的欧拉坐标系中求解流体运动方程；固体所占区域中的格点上的流体力学参数由镜像关系指定，从而使相界面无滑移边界条件得到隐含满足。固体区域的虚拟流场应与外部真实流体流场的速度矢量关于界面反对称，压力场则镜面对称。镜像流体方法具有物理意义明确、处理方式简洁的优点，是一种新的处理液固两相流动的计算流体力学方法。 本文数值模拟了无挡板圆柱形椭球底搅拌槽内液固两相搅拌运动，将镜像流体方法处理的对象扩展到三维湍流问题。搅拌槽物理模型上部为圆柱形，底部为椭球形；搅拌槽直径T = 0.3 m，高度H = 0.4 m，壁面上无档板；搅拌桨为三叶斜叶桨，桨叶与水平方向成70度角，直径D=0.16 m；搅拌桨中心平面与搅拌槽底面的距离为：C=0.186 m；底部椭球长轴为0.15 m，短轴为0.12 m。模拟研究了不同转速条件、桨叶位置等条件下搅拌槽内的速度及相含率分布。得到的模拟结果与实验结果较为接近，证明了镜像流体法处理斜叶桨和椭球底面的有效性，提供了轴流桨搅拌反应器数值模拟的新途径。
英文摘要	Pitched Blade Turbine (PBT) is widely used in various agitated reactors involved with solid-suspensions, due to its good axial flow performance. Because PBT has complicated geometrical shape, there are still some difficulties in dealing the pitched blade turbines with existing numerical methods. In this thesis, the Mirror Fluid Method (MFM) is used to deal with the PBT. The main idea of MFM is to apply the mirror rules at the interface between the fictitious fluid within the solid region and the real fluid region, solve the momentum equations in the frame of Eulerian coordinates, designate the fluid parameters at the nodes in the solid region according to the mirror rules, so as to satisfy the non-slip boundary condition at the interface implicitly. Therefore, the virtual flow field inside the solid region should be equal in value but opposite in sighs with that at the mirror point about the boundary for the velocity vectors, while pressure field should have the same value with that at the mirror point. MFM is a brand new method for simulating fluid flow with solid boundaries, which is clear in physical meanings, and easy to be complimented. The simulation of solid-liquid flow inside a non-baffled columniform stirred vessel with an elliptical bottom is addressed in this thesis, expanding the target of MFM to 3D turbulent flow. The physical model of the stirring vessel constitutes an upper column and a lower half elliptical bottom. The diameter of the tank is T = 0.3 m and the height is H = 0.4 m. The stirring turbine is 3-blade PBT, with 70º angle between the blade and the horizontal direction, with inner diameter D=0.16 m. The distance between the middle plane of the turbine and the bottom of the vessel is C=0.186 m. The long axis of the bottom ellipse is 0.15 m, and the short axis is 0.12 m. The velocities and solid holdup distributions under different agitation speeds, positions of PBT, etc. are studied. The simulation results accord with the experimental results, which vindicates the effectiveness of the MFM for computing PBT flows, and MFM is a new approach in the PBT reactor simulation.
语种	中文
公开日期	2013-09-13
页码	108
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1211]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	张超. 镜像流体法模拟斜叶桨搅拌槽[D]. 过程工程研究所. 中国科学院过程工程研究所. 2008.

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