Williamson流体在黏性耗散和均匀磁场作用下四次自催化化学反应的熵优化

摘要

This research elaborates magnetohydrodynamics (MHD) impact on non-Newtonian (Williamson) fluid flow by stretchable rotating disks. Both disks are rotating with different angular velocities and different stretching rates. Viscous dissipation aspect is considered for energy expression formulation. Entropy generation analysis is described via implementation of thermodynamic second law. Chemical processes (heterogeneous and homogeneous) subjected to entropy generation are introduced first time in literature. Boundary-layer approach is employed for modeling. Apposite variables are introduced for non-dimensionalization of governing systems. Homotopy procedure yields convergence of solutions subjected to computations of highly nonlinear expressions. The significant characteristics of sundry factors against thermal, velocity and solutal fields are described graphically. Besides, tabular results are addressed for engineering quantities (skin-friction coefficient, Nusselt number). The outcomes certify an increment in temperature distribution for Weissenberg (We) and Eckert (Ec) numbers.%阐述了可伸缩的旋转盘对非牛顿磁流体动力学(MHD)的影响.两个圆盘以不同的角速度和不同的伸缩率旋转.在能量表达式中考虑黏性耗散,利用热力学第二定律分析熵的生成,文中首次介绍了熵产生的化学过程(多相和均相).采用边界层方法建立模型,引入变量对控制系统进行无量纲化.通过高度非线性表达式的计算,得到同伦过程解的收敛性.用图解法描述了各种因素对热场、速度场和溶质场的影响特征.此外,以表格形式给出了工程质量包括表面摩擦系数、Nusselt数的计算结果.结果证实了因Weissenberg(We)(韦斯森伯格)和Eckert(Ec)(埃克特)数而导致的温度梯度分布的增加.