界面剪切力作用下波状液膜流的水动力稳定性  

HYDRODYNAMIC STABILITY OF A LIQUID WAVY FILM WITH INTERFACIAL SHEAR

作　　者：叶学民[1] 李春曦[1] 王松岭[1] 

机构地区：[1]华北电力大学能源与动力工程学院,保定071003

出　　处：《力学学报》2009年第3期307-312,共6页Chinese Journal of Theoretical and Applied Mechanics

基　　金：高等学校博士学科点专向科研基金资助项目(20040079004)~~

摘　　要：液膜流的水动力稳定性作为保障其高效传热传质性能的重要因素之一,受多种因素的制约和影响.当气液界面处存在因气流流动而产生剪切力作用时,剪切力将通过改变界面处的边界条件,从而影响液膜流动的稳定性.基于边界层理论,采用积分法建立了剪切力作用下降液膜表面波演化方程,分析了界面剪切力对水动力稳定性的影响.研究表明,正向剪切力为不稳定性因素,反向剪切力在较小雷诺数时为不稳定因素,在大雷诺数时为稳定性因素;正向剪切力使临界波数和临界波速增大,反向剪切力使其减小;剪切力对临界波速的影响在不同雷诺数下也有所不同.The hydrodynamic stability of a liquid wavy film is important to guarantee its function for efficient heat and mass transfer. However, the stability has been affected by various factors. Under a gas flow at the gas-liquid interface, the stability is obviously influenced by the interracial shear at the boundary condition. The evolution equation of the surface waves under shear effect is derived with the integral approach based on the boundary layer theory, and the effect of interracial shear on the stability under different conditions is illustrated with the present model. The theoertical results show that film flow tends to be unstable under the cocurrent shear, and the effect of countercurrent shear plays a positive role under lower Re and a negative role under higher Re. The critical wave number and critical wave velocity increase under the cocurrent shear and decrease under countercurrent shear. Therefore, the effect of interfacial shear on critical wave velocity is clearly different under different Reynolds number.

关 键 词：波动液膜 界面剪切力 表面波 稳定性 边界层理论 

分 类 号：O352[理学—流体力学]