Purpose

This study aims to investigate the flow behavior of aluminum oxide–water nanofluid with variable viscosity flowing through the microchannel parallel with the ground, with low aspect ratio. The study focuses on the first and second law analyses of Poiseuille flow using water as the base fluid with alumina nanoparticles suspended in it. Combined effects of thermal radiation, viscous dissipation, variable viscosity, nanoparticle shape factor and volume fraction on the thermal performance are studied and the in-built irreversibility in the process is examined.

Design/methodology/approach

The governing equations with dimensions are reduced to non-dimensional equations by using dimensionless quantities. Then, the Runge–Kutta–Fehlberg shooting scheme tackles the present non-linear equations.

Findings

The outcomes of the present analysis reveal that the activation energy parameter with its increase, depletes the exergetic effectiveness of the system, thus defending the fact to keep the activation energy parameter the lowest as possible for the system efficiency. In addition, thermal radiation and Biot number enhance the release of heat energy, thereby cooling the system. Bejan number graph exhibits the decreasing behavior for the increased nanoparticle shape factor, whereas the temperature enhances with the rise in nanoparticle shape factor.

Originality/value

The effects of nanoparticle shape factor in Poiseuille flow for alumina–water nanoliquid in low aspect ratio microchannel is inspected at the earliest. Exergetic effectiveness of the system is studied and heat transfer characteristics are explored for thermal radiation effect and activation energy parameter. Besides, BeηSphere>BeηBlades.

中文翻译：

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可变粘度和对流冷却的Al2O3-H2O纳米流体Poiseuille流的内在不可逆性

目的

这项研究旨在研究具有低粘度的可变粘度的氧化铝-水纳米流体流经与地面平行的微通道的流动行为。该研究着重于以水为基础流体并悬浮有氧化铝纳米粒子的泊桑叶流动的第一定律和第二定律分析。研究了热辐射，粘性耗散，可变粘度，纳米颗粒形状因子和体积分数对热性能的综合影响，并研究了过程中的内在不可逆性。

设计/方法/方法

通过使用无量纲的量，具有维数的控制方程被简化为无量纲的方程。然后，Runge-Kutta-Fehlberg射击方案解决了当前的非线性方程。

发现

本分析的结果表明，活化能参数的增加会耗尽系统的能量，因此捍卫了将活化能参数保持为系统效率最低的事实。另外，热辐射和比奥数提高了热能的释放，从而冷却了系统。Bejan数图显示出随着增加的纳米颗粒形状因子而降低的行为，而温度随纳米颗粒形状因子的升高而升高。

创意/价值

最早研究了低纵横比微通道中氧化铝-水纳米液体的纳米粒子形状因数在泊瓦流动中的作用。研究了系统的显着有效性，并探讨了热辐射效应和活化能参数的传热特性。除了， 乙Ëη小号pHË[RË>乙Ëη乙升一种dËs。