Abstract: Reynolds stress model was used to simulate zero axial velocity surface of gas phase flow field in cylindrical cyclone separator.The effects of rotational flow instability,inlet velocity and structural parameters such as inlet area and vortex finder diameter on the distribution of zero axial velocity surfaces were studied.The results show that zero axial velocity boundaries exhibit contorted state in the whole separated space due to the inherent existence of rotational flow instability.In the velocity range studied,the flow field is in mould area and the separator is in kinematic similarity,so the inlet velocity has little effect on zero axial velocity boundaries.Vortex finder diameter and inlet area have significant effects on zero axial velocity boundary around the vortex finder entrance.With the decrease of vortex finder diameter and increase of inlet area,zero axial velocity boundary shrinks gradually.Far away from the vortex finder entrance,the effect of vortex finder diameter and inlet area abates and the width of zero axial velocity boundary increases gradually and trends are similar.The separator with specific vortex finder diameter and inlet area that make the flow field stable can make zero axial velocity boundary of cross section keep preferable circular degree.Simulation results can provide reference on separation mechanism research and structure optimization of separator.

Key words: cyclone separator, axial velocity, zero axial velocity surface, numerical simulation

摘要： 采用雷诺应力模型对柱状旋流分离器气相流场中的零轴速包络面分布进行了数值模拟分析,考察了旋流不稳定性、流速以及结构参数变化对其分布的影响。指出由于分离器旋转流动不稳定性的固有存在,零轴速边界在整个分离空间会呈非轴对称的扭曲状态;在研究速度范围内,流场处于自模化区,分离器运动相似,入口速度变化对零轴速边界的分布影响不大;升气管直径与入口面积对升气管入口区域的零轴速边界分布影响较大,随升气管直径的减小和入口面积的增大,零轴速边界逐渐收缩。远离升气管入口区域,升气管直径与入口面积的影响减弱,零轴速边界宽度逐渐增大,并趋于一致;使流场趋于稳定的升气管直径与入口面积,截面零轴速边界会保持较好的圆度。

关键词: 旋流分离器, 轴向速度, 零轴速包络面, 数值模拟