摘要水力旋流器是一种利用离心力场实现高效分离的分离设备，其性能优于利用重力 场的分离设备。流体经过切向入口进入旋流器内部，在短时间内从入口处的一维流动 转变为沿旋流器内壁的强旋流，因此旋流器内部流场的数值模拟非常复杂。81369
本文利用计算流体力学(CFD)软件 FLUENT，采用雷诺应力模型(RSM)对旋流器 内部单相流场进行数值模拟。根据数值模拟结果分析旋流器内部流场分布情况，获得 各个截面的压力和速度分布，流场分布与前人理论分析和实验结果一致。并利用离散 相模型(DPM)对旋流器内不同直径固体颗粒运动轨迹进行模拟，分析旋流器分离过程 中固体颗粒运动规律，获得旋流器的分离效率。
本文用于固液两相流分离的旋流器采用蜗壳式切向入口以减弱流体在入口部分 的能量损失，提高旋流器的分离性能。并分别对双入口型和双锥段型两种不同形式的 蜗壳式切向入口旋流器进行数值模拟。结果表明，双锥段形型旋流器对于小粒度颗粒 的分离效果优于其他两种结构形式。并且，双入口型旋流器内部流场的对称性和稳定 性最好。不同结构形式的蜗壳式切向入口旋流器内部流场均表现为双螺旋结构，采用 蜗壳式切向入口有助于减少湍流和能量损失，从而提高旋流器分离效率。
毕业论文关键词：水力旋流器，数值模拟，雷诺应力模型，离散相模型，两相流
Abstract Hydrocyclones carry out the separation by centrifugal force field, it is more powerful than the gravity separation equipment。 The flow field can be turn to be strong flow along the inner wall from the one-dimensional flow through the tangential inlet in a very short period of time, which make it pretty complex to make a numerical stimulation of hydrocyclone。
In this paper, stimulation of single phase turbulence in hydrocyclones were carried out by use of the computational fluid dynamics (CFD) software FLUENT and the Reynolds Stress Model (RSM)。 According to the stimulation results of the hydrocyclone, analyzed the pressure and three-dimensional velocity distribution, obtained within the different sections of the cyclone which is the same as the further study and experiment of cyclone。 By use of Discrete Phase Model (DPM) on the numerical simulations of particles with different diameter in the multiphase flow field, analyzed the track of the particles and obtained separation efficiency。
The hydrocyclones used in this paper for separation of solid-liquid two phase flow applied tangential spiral entrances which contributed to reduction of the energy consumption through the entrance。 Comparative study of different structural forms in solid-liquid separator for spiral entrance cyclone, included the dual tangential inlet type and double cone type。 The results show that when there is a lower level of diameter of particles in the two- phase fluid, double cone cyclone separation efficiency is better than the other two structural forms。 Meanwhile the dual tangential inlet cyclone-type flow field shows the best stability and symmetry。 Different structural forms of spiral entrance cyclone field perform as double- helix structure。 The cyclone entry structure is designed as Archimedes spiral entrance to increase fluid rotational speed, reduce the energy consumption and finally improve the separation efficiency。
Keywords: hydrocyclone; numerical stimulation; Reynolds stress model; Discrete phase model; two-phase flow;
目 录
第一章 绪论 1
1。1 研究背景和意义 1
1。2。1 结构参数的优化 FLUENT蜗壳式切向入口旋流器性能研究:http://www.youerw.com/jixie/lunwen_95068.html