降液膜波动的影响因素分析  

Analysis on Wave Flow of Laminar-Wavy Falling Liquid Film

作　　者：马学虎[1] 薄守石[1] 兰忠[1] 陈嘉宾[1] 陈宏霞[1] 白涛[1] 

机构地区：[1]大连理工大学化学工程研究所,辽宁大连116012

出　　处：《高校化学工程学报》2010年第1期10-15,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家863项目(2007AA05Z214);教育部新世纪优秀人才基金项目(NCET-05-0280)

摘　　要：建立了溴化锂溶液沿平板降膜的流动模型。利用VOF方法捕捉降液膜的自由流动表面,利用CSF模型考虑表面张力对降液膜流动的作用,研究了入口扰动频率、降膜Re和平板倾斜角对降膜波动演化过程的影响。模拟结果表明,入口处的低频率扰动发展为孤波,随着频率的增加,波长减小,孤波与孤波通过他们之间的波后、衬底和毛细波相互影响,而高频率扰动演变成毛细波。随着Re的增加,波幅和波长增加,同时波峰处的循环流动强度增加。随着倾斜角的增加,重力沿流动方向的分力增加,波发展速度增加。同时分析了波内的速度场和壁面切应力等动力学特性。Using aqueous LiBr solution as flowing fluid, flow dynamics of falling film along a wall was carried out. the numerical simulation about wave evolution and Volume of Fluid （VOF） model was used to track the free surface of the falling film and the Continuum Surface Force （CSF） model was used to consider the effect of the surface tension of the fluid on the dynamic boundary conditions of the falling film. The simulation results show that the small disturbance with low frequency at the flow inlet may give rise to a solitary roll wave with large amplitude and some small amplitude capillary waves in front of it. When the disturbing frequency at the flow inlet is increased, the solitary waves become closer, and via the wave tail and capillary waves between them, the solitary waves interact on each other; and when the disturbing frequency is high, the wave amplitude becomes smaller and the accompanying capillary waves disappear. Furthermore, as the Reynolds number of the flow is increased, the wave amplitude, wave length and the intensity of recirculation in the ridge of the wave increase; and as the inclined angle of the wall is increased, the component of the gravity parallel to the wall increases, thus the wave grows more quickly. Moreover, in this work, the velocity vectors in the wave and the shear stress on the wall surface were investigated.

关 键 词：LIBR 降膜 波动力学 模拟 

分 类 号：TQ021.1[化学工程]