多孔饱和矩形管中粘性随温度变化对熵产、热和流体流动的影响  

Effects of Temperature-Dependent Viscosity Variation on Entropy Generation,Heat,and Fluid Flow Through a Porous-Saturated Duct of Rectangular Cross-Section

作　　者：K·霍曼 H·戈金西 吴承平（译） 张禄坤（校） 

机构地区：[1]昆士兰大学工程学院,布利斯本,澳大利亚 [2]不详

出　　处：《应用数学和力学》2007年第1期61-69,共9页Applied Mathematics and Mechanics

摘　　要：研究了充填流体-饱和多孔介质的矩形管中,随温度变化的粘性对充分发展强迫对流的影响.采用Darcy流动模型并假设粘性-温度为倒线性关系.管壁视为均匀热通量,即Kays和Craw-ford称为的H边界条件.当流体粘性随温度升高而降低时,管壁的Nusselt数增大.求解速度和温度分布时,利用热力学第二定律求解了局部平均熵产率.根据Brinkman数、Péclet数、粘性变化数、无量纲管壁热通量和管道截面宽高比,给出了熵产率、Bejan数、传热不可逆性和流体流动不可逆性的表达式.这些表达式是该类问题参数研究的基础.可以看出,当管道截面宽高比的增大使熵产率减小时,方形管中流动产生的熵大于矩形管,这类似于Ratts和Raut研究的明流(clear flow)情况.Effect of temperature-dependent viscosity on fully developed forced convection in a duct of rectangular cross-section occupied by a fluid-saturated porous medium is investigated analytically. The Darcy flow model was applied and the viscosity-temperature relation was to be an inverse-linear one. The case of uniform heat flux on the walls, i.e. the H boundary condition in the terminology of Kays and Crawford, was treated. For the case of a fluid whose viscosity decreases with temperature, it is found that the effect of rite variation is to increase the Nusselt number for heated walls. Having found the velocity and the temperature distribution, the second law of thermodynamics was invoked to find rite local and average entropy generation rate. Expressions for the entropy generation rate, the Bejan number, the heat transfer irreversibility, and the fluid flow irreversibility were preseated in terms of the Brinkman number, the Péclet number, the viscosity variation number, the dimensionless wall heat flux, andthe aspect ratio （width to height ratio）. These expressions let a parametric study of the problem rinsed on which it is observed flint the entropy generated due to flow in a duct of square cross-section is more than those of rectangular counterparts while increasing the aspect ratio decreases the entropy generation rate similar to what previously reported for the clear flow case by Ratts and Raut.

关 键 词：熵产率 强迫对流 多孔介质 矩形管 随温度变化的粘性 

分 类 号：O357.3[理学—流体力学]