热泳和Brown运动对太阳能辐射下热分层纳米流体边界层流动的影响  

Thermophoresis and Brownian Motion Effects on Boundary-Layer Flow of a Nanofluid in the Presence of Thermal Stratification Due to Solar Energy

作　　者：N·安布泽志昂 K·斯里尼瓦桑 K·钱德拉塞卡兰 R·坎达沙密 海治(译) 张禄坤(校) 

机构地区：[1]斯里古鲁技术学院机械工程系,哥印拜陀641110,印度 [2]安那大学机械工程系,金奈600025,印度 [3]RMK工程学院机械工程系,金奈600040,印度 [4]马来西亚敦胡先翁大学FSTPi计算数学研究中心,新山86400,马来西亚 [5]不详

出　　处：《应用数学和力学》2012年第6期726-739,共14页Applied Mathematics and Mechanics

摘　　要：在太阳辐射下的纳米流体中,数值地研究竖向延伸壁面具有可变流条件时的层流运动.使用的纳米流体模型为,在热分层中综合考虑了Brown运动和热泳的影响.应用一个特殊形式的Lie群变换,即缩放群变换,得到相应边值问题的对称群.对平移对称群得到一个精确解,对缩放对称群得到数值解.数值解依赖于Lewis数、Brown运动参数、热分层参数和热泳参数.得到结论:上述参数明显地影响着流场、温度和纳米粒子体积率的分布.显示出纳米流体提高了基流体热传导率和对流的热交换性能,基流体中的纳米粒子还具有改善液体辐射性能的作用,直接提高了太阳能集热器的吸热效率.The problem of laminar fluid flow resulted from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energ was investigated numerically.The model used for the nanofluid incorporated the effects of Brownian motion and thermophoresis in the presence of thermal stratification.The symmetry groups admitted by the corresponding boundary value problem were obtained by using a special form of Lie group transformations viz.scaling group of transformations.An exact solution was obtained for translation symmetry and numerical solutions for scaling symmetry.This solution depended on a Lewis number,Brownian motion parameter,thermal stratification parameter and thermophoretic parameter.The conclusion was drawn that the flow field and temperature and nanoparticle volume fraction profiles were significantly influenced by these parameters.Nanofluids were shown to increase the thermal conductivity and convective heat transfer performance of the base liquids.Nanoparticles in the base fluid also offered the potential of improving the radiative properties of the liquids,leading to an increase in the efficiency of direct absorption solar collectors.

关 键 词：太阳辐射 BROWN运动 纳米流体 热泳 热分层 

分 类 号：O357.1[理学—流体力学]