Entropy analysis of unsteady magnetohydrodynamic thin liquid film flow of Maxwell nanofluids with variable fluid properties
Entropy analysis of unsteady magnetohydrodynamic thin liquid film flow of Maxwell nanofluids with variable fluid properties
复制标题
具有可变流体性质的麦克斯韦纳米流体非定常磁流体动力薄液膜流的熵分析
DOI：
10.1016/j.matchemphys.2022.126890
复制
发表时间：
2022
影响因子：
4.6
通讯作者：
G. C. Shit
中科院分区：
文献类型：
--
作者：
S. Mandal;G. C. Shit
粘性流体在膨胀平面上薄膜中的流动和传热现象在许多工艺过程中具有良好的应用前景。薄膜内的传热传质速率对涂层工艺的性能和产品的化学性质具有明确的影响。本文研究了麦克斯韦纳米流体在指数拉伸表面上的非定常边界层磁流体动力薄膜流动，该流动受到滑移对速度和边界吸注的影响。热传递机制受热辐射、与温度相关的热导率、能量的粘性耗散和非均匀热源/散热器的影响。我们已经分析了系统的熵产生，通过适当注意到可变的流体性质和膜厚度。通过适当的自相似变换，将流体流动的时变耦合非线性偏微分方程组转化为常微分方程组。简化的两点边值问题，然后解决了著名的龙格-库塔-Fehlberg积分技术的基础上射击法的援助。数学模型提出了一个额外的运动边界条件，利用该边界条件，采用牛顿-拉夫逊法计算薄膜的厚度。研究表明，磁参数、辐射参数、粘度参数、热导率参数等控制参数对薄膜的速度场、温度场、努塞尔数和厚度有很大的影响。此外，磁场强度、热辐射、能量耗散、热导率参数、粘性参数和热源/热汇的变化对热不可逆性的量度Bejan数有很大的影响。
The flow and heat transfer phenomena of a viscous fluid in a thin film over an expanding flat surface possesses optimistic applications in a large number of technological processes. Heat and mass transfer rate within the thin film bears an unequivocal factors on the performance of coating process and the chemical nature of the product. This article concerns with the study of unsteady boundary layer magnetohydrodynamic thin film flow of Maxwell nanofluid past over an exponentially stretching surface subject to slip effect on velocity and suction/injection at the boundary. The heat transfer mechanism is influenced by the thermal radiation, temperature dependent thermal conductivity, viscous dissipation of energy and a non-uniform heat source/sink. We have analyzed the entropy generation of the system by paying due attention to the variable fluid properties and film thickness. The system of arising time dependent coupled nonlinear partial differential equations governing the fluid flow are converted into a system of ordinary differential equation by utilizing suitable self-similar transformations. The reduced two-point boundary value problem is then solved with the aid of well known Runge–Kutta–Fehlberg integration technique based shooting method. The mathematical model suggests an extra kinematic boundary condition which is utilized to compute the thickness of the thin film by employing the Newton–Raphson method. The investigation highlights that the arising controlling parameters such as magnetic parameter, radiation parameter, viscosity parameter, thermal conductivity parameter have strong effect on velocity field, temperature field, Nusselt number, and the thickness of the thin film. Moreover, the Bejan number, a measure of thermal irreversibility, is highly affected by the variation of the magnetic field strength, thermal radiation, dissipation of energy, thermal conductivity parameter, viscosity parameter and heat source/sink.