摘要
利用粒子图像测速技术对曝气反应器中基本流动形态进行研究,得出各工况下速度矢量图及参数,根据计算分别讨论了液相速度和雷诺应力的一系列变化。结果表明,挡板间距越小液体上升流动速度越大;且曝气量越大,垂直平均、脉动强度和雷诺应力值也随之增大,但脉动强度的波动分布均匀不随平均速度变化,雷诺应力在各区的断面2有所降低;单管曝气对液相湍动的最大影响范围在曝气管前后10cm左右;曝气量为7.5m3/h时系统处于不稳定状态;速度的脉动直接影响雷诺作用力的变化趋势,从而影响反应器中流体的湍动情况,所以,在加入膜组件后在充分考虑反应器内液体流动所需速度的同时,也要考虑速度脉动的频率和大小。
The particle image velocimetry was used to study the basic flow pattern in the aeration reactor. The velocity vector and parameter of different conditions were obtained to discuss changes of liquid veloci-ty and Reynolds stress. The results show that the smaller the baffle spacing is, the greater the liquid flow velocity is. Vertical average velocity, fluctuating strength and Reynolds stress value increased with aera- tion rate. However, the fluctuating strength does not change with average velocity and distributed even- ly, the Reynolds stress is decreased in section 2 at each region; The influence range.＂ of single-tube aera- tion is around the aeration pipe 10 cm; System is instable while aeration rate of 7.5 m^3/h; The pulsation of velocity directly impacts on the trend of the shear force, which affects the fluid turbulence in the reac-tor. When the membrane is put on, the speed, the frequency and size of fluctuation of liquid flow are re-quired to consider.
出处
《力学季刊》
CSCD
北大核心
2012年第4期535-543,共9页
Chinese Quarterly of Mechanics
基金
国家自然科学基金项目(50766002)
内蒙古自然科学基金重大项目(2010ZD11)
关键词
气液两相流
曝气量
脉动强度
雷诺应力
gas-liquid two phase flow
aeration
fluctuating strength
Reynolds stress
