摘要近年来,应用CFD方法对搅拌釜反应器的研究引起了广泛的关注。本文应用Fluent软件,采用欧拉-欧拉双流体模型,液相主流区域采用标准 湍流模型,桨处采用多重参考系(MRF)模型,对配备有单六直叶涡轮桨(标准Rushton桨)的两种不同搅拌釜进行了数值模拟,研究了气-液两相流场、整体及局部气含率,并对不同进气速度下的整体及局部气含率进行对比。结果表明:整个搅拌釜液相流场以桨为界,分为上下两个循环区域;釜内整体以及局部气含率整体随着进气速度的增大呈现上升趋势,并且桨所在平面气含率明显高于其它平面。60115
毕业论文关键词:CFD 双流体模型 标准 湍流模型 气含率 多重参考系
毕业设计说明书(论文)外文摘要
Title Investigate the gas holdup in the gas –liquid stirred tank by using computational fluid dynamics method
Abstract
Recently, using computational fluid dynamics (CFD) method to simulate stirred tank reactors has attracted many attentions. In this work, based on the Euler-Euler two-phase flow model, standard turbulent model and multiple reference frames (MRF) method, Fluent has been applied to simulate the two kinds of different gas-liquid stirred tanks, agitated by a single six-blade standard Rushton turbine. The gas-liquid flow field, the global gas holdup and the local gas holdup were investigated. The global gas holdup variations and the local gas holdup variations were also discussed as the gas inlet velocity slowly increases. And the result shows that the global liquid flow field is pided by the turbine into two circulation parts. The global gas holdup and the local gas holdup rise as the gas inlet velocity increases, and the gas holdup of the plane where the turbine located in is obviously higher than that of the other planes.
Key words: CFD two-phase flow model standard turbulent model gas holdup multiple reference frames
1 绪论 1
1.1 气-液两相的CFD研究进展 1
1.2 CFD软件简介 3
2 气-液两相流模拟方法及模型 5
2.1 气-液两相流模拟方法 5
2.2气-液两相流模型 5
2.2.1 Euler-Euler双流体模型 5
2.2.2 PBM模拟方法 7
2.2.3标准 模型 8
2.2.4 CFD对桨的模拟方法 9
2.3模拟策略 10
2.3.1 网格划分 10
2.3.2 边界条件 10
2.3.3计算策略 11
3 单桨搅拌釜内气-液两相流的模拟 12
3.1搅拌釜结构 12
3.2 模拟工况 13
3.3 模拟方法 13
3.4 边界条件及流域的设定 14
4 搅拌釜内气-液两相流数值模拟结果及分析 15
4.1 气-液搅拌釜内流场的模拟 15
4.2 气含率的模拟 15
4.2.1整体气含率 16
4.2.2局部气含率 16