Abstract

The intention behind this research work is to analyze the flow, heat transfer and entropy generation in a vertical channel filled with a nanofluid. The vertical microchannel is made of two parallel porous and slippy plates. The hot fluid is injected from the left side and succeeded from the right side. Fluid flow within the channel is induced due to an applied favorable/adverse pressure gradient (due to Couette–Poiseuille flow), right plate movement, buoyancy force due to the temperature difference of the channel plates in the presence of heat generation/absorption inside the channel and subjected to a constant applied transverse magnetic field. The resulting governing equations are solved numerically by the shooting method. The conventional fluids are chosen as water, and ethylene glycol-water mixture. The nanoparticles are selected as Al₂O₃ and CuO. Nanofluids modeling, which takes care of base fluid temperature, Brownian motion, diameter and concentration of nano particles, and base fluid physical properties are considered here. Roles of pressure gradient P (at the inlet), temperature of base fluids, heat generation/absorption, the density of the nanoparticle volume fraction on flow and heat transfer characteristics (velocity and temperature distribution, Nusselt number (Nu) distribution, entropy generation and Bejan Number) are investigated here. How the sequence of appearance of curves of flow and heat transfer characteristics (due to variation of aforesaid parameters) are disturbed by the presence of injection/suction, radiation and convective boundary condition is discussed here. A critical analysis is conducted on the individual contribution of irreversibilities due to heat flow, fluid friction and Joule heating to the total entropy generation. At last, we try to find an optimum condition at which local and global entropy generation are minimally generated in the channel.

中文翻译：

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对流辐射条件下 MHD 库埃特-泊肃叶纳米流体流过光滑多孔微通道的基液、温度和热源：熵分析

摘要

这项研究工作的目的是分析填充纳米流体的垂直通道中的流动、传热和熵产生。垂直微通道由两个平行的多孔滑板组成。热流体从左侧注入并从右侧继续注入。由于施加的有利/不利压力梯度（由于库埃特-泊肃叶流）、右板运动、由于通道板内部存在热量产生/吸收的温差而产生的浮力，引起通道内的流体流动。通道并受到恒定施加的横向磁场的影响。由此产生的控制方程通过打靶法进行数值求解。常规流体选择水和乙二醇-水混合物。纳米颗粒选择Al ₂ O ₃ 和CuO。这里考虑了纳米流体建模，它考虑了基础流体温度、布朗运动、纳米颗粒的直径和浓度以及基础流体物理性质。压力梯度 P（入口处）、基液温度、热量产生/吸收、纳米粒子体积分数的密度对流动和传热特性（速度和温度分布、努塞尔数 (Nu) 分布、熵产生和Bejan 号码）在这里进行调查。这里讨论喷射/吸入、辐射和对流边界条件的存在如何干扰流动和传热特性曲线的出现顺序（由于上述参数的变化）。对热流、流体摩擦和焦耳热导致的不可逆性对总熵产生的单独贡献进行了批判性分析。最后，我们试图找到一个最佳条件，在该条件下，通道中局部和全局熵的生成最少。