摘要
通过微元管内流动模型,研究了液态金属熔体泡沫体内单条Plateau边界内析液过程中的速度场.分析了不同Newton表面粘度,即不同的气液界面运动能力(无量纲参数M)下,Plateau边界内速度的分布.结果显示:在相同的气液界面运动能力和曲率半径条件下,泡沫体内固壁处Plateau边界内速度约是内部Plateau边界内速度的6～8倍,从而解释了不同容器内泡沫体析液速率的差异现象;发现M存在1个临界值,在此值的两边,液膜厚度与曲率半径的比值对Plateau边界内速度的影响呈现出相反的趋势.结合多尺度方法,进而利用微观计算结果建立了泡沫体的整体宏观析液模型,将模型计算结果和经典析液方程计算结果及实验值作了比较,结果表明:该文模型计算结果与实验值在泡沫层上部、中部吻合较好,M值和气泡大小对析液过程有显著影响.
Velocity field in a single plateau border of aluminum foam during drainage process was studied by a mathematic model for the flow inside a micro-channel. It is shown that the liquid/gas interrace mobility, which is characterized by the Newtoniau surface viscosity, tins substantial effect on velocity inside single plateau border. It＇s found that at the same liquid/gas interracial mobility （M） and same radius of curvature, the max velocity inside an exterior plateau border is about 6 ~ 8 times as large as that inside an interior plateau border. It＇s also found that a critical value of the interfacial mobility in interior plateau border, for values greater or less than which the effects of the film thick- ness on the velocity in plateau border show opposite tendencies. Based on the results from the microscopical model, a new macroscopical drainage model was presented for altuninum foams. Comparisons of computed results by this model with experimental data from the literature and with those from the classical drainage equation show a reasonable agreement. Furthennore, computational results reveal that the liquid holdup of foams is dependent strongly on the value of M and bubble radius.
出处
《应用数学和力学》
CSCD
北大核心
2009年第12期1453-1462,共10页
Applied Mathematics and Mechanics
基金
国家自然科学基金资助项目(50876017)
