Computers and Mathematics with Applications Laminar Flow and Heat Transfer in the Boundary-layer of Non-newtonian Fluids over a Stretching Flat Sheet
Computers and Mathematics with Applications Laminar Flow and Heat Transfer in the Boundary-layer of Non-newtonian Fluids over a Stretching Flat Sheet
复制标题
DOI：
--
复制
发表时间：
--
期刊：
影响因子：
--
通讯作者：
Hang Xu;S. Liao
中科院分区：
文献类型：
--
作者：
Hang Xu;S. Liao
关键词:幂律非牛顿流体边界层流动传热传质相似解解析近似a b str a c t给出了幂律非牛顿流体在拉伸薄板上的层流边界层流动和传热的理论分析，其中薄板速度分布为U w = Cx m，壁面温度分布为t w = t∞+ Ax γ。式中，x表示到表面出现的狭缝的距离，C和A为常数，m和γ分别表示薄片速度指数和温度指数。在边界层近似的框架内，将非线性边界层动量方程和能量方程简化为一组常微分方程。发现当速度指数m = 1/3或幂律指数n = 1时，动量方程和能量方程都存在相似解。采用基于同伦分析方法的新方法，得到了速度和温度曲线的高精度解析近似。此外，还研究了参数m、n和普朗特数Pr对流动的影响。
Keywords: Boundary-layer flow Power-law Non-Newtonian fluids Heat and mass transfer Similarity solutions Analytical approximations a b s t r a c t A theoretical analysis of the laminar boundary-layer flow and heat transfer of power-law non-Newtonian fluids over a stretching sheet with the sheet velocity distribution of the form U w = Cx m and the wall temperature distribution of the form T w = T ∞ + Ax γ is presented, where x denotes the distance from the slit from which the surface emerges and C and A are constants, m and γ denote, the sheet velocity exponent and the temperature exponent, respectively. Within the framework of the boundary layer approximations, the nonlinear boundary layer momentum equation and the energy equation are reduced to a set of ordinary differential equations. It is found that when the velocity exponent m = 1/3 or the power-law index n = 1, the similarity solutions are in existence for both the momentum equation and the energy equation. Analytical approximations with high accuracy for the reduced velocity and temperature profiles are obtained using a new procedure based on the homotopy analysis method. Besides, the effects of the parameters m, n and the Prandlt number Pr on the flow are investigated.