摘要
利用计算流体力学法研究了中等Reynolds数下(25≤Re≤500)气泡界面污染程度对其尾流的影响。借鉴圆球绕流和停滞帽模型,提出了一种模拟中等Reynolds数下受污染球形气泡尾流的三维模型,气泡界面污染程度取决于帽角(θ)的大小,帽角越大表示气泡表面污染程度越小。研究发现:Re=25~200时,污染程度的减小会减小尾涡长度(s)、分离角(φ)以及涡中心位置(l)和(h)的数值,但不会改变其与Reynolds数表征的关系;污染程度的减小会使Re=250~500时尾涡的三维特性减弱,使Re=350时有序脱落的尾涡的强度减小并最终使其不发生脱落,使Re=500时无规律脱落的尾涡的无序性减弱并最终使其不发生脱落。
The numerical method is employed to investigate the influence of contaminated degree of bubble surface on its wakes for the spherical bubble under moderate Reynolds number（25≤Re≤500）. By referencing the flow past a sphere and the stagnant cap model, one kind of three-dimensional model for contaminated spherical bubble under moderate Reynolds number is proposed. The interface contaminated degree is dependent on the magnitude of the cap angle. The larger the cap angel is, the slighter the bubble interface pollution is. The present results show that, for 25≤Re≤200, the magnitudes of the vortex length, the vortex center position distance to the bubble rear and the separation angle decrease with the decrease of the bubble surface contaminated degree but the distribution trends of those parameters against the Reynolds number are similar; for 250≤Re≤500, the decrease of the bubble surface contaminated degree weakens the three-dimensional property of vortexes, reduces the strength of orderly shedding vortexes until the shedding phenomenon disappears at Re=350, and reduces the disorder of shedding vortexes until the shedding phenomenon disappears too at Re=500.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2017年第9期3409-3419,共11页
CIESC Journal
基金
国家自然科学基金项目(51376026)
江苏省青蓝工程项目~~
关键词
气泡
界面
尾流
层流
流体动力学
bubble
interface
wake
laminar flow
hydrodynamics
