Purpose

The purpose of this study is to numerically investigate the confined single-walled carbon nanotube-water nanofluid jet impingement heating of a cooled surface with a uniform heat flux in the presence of a porous layer. The analysis of the convective heat transfer mechanism is introduced considering the buoyancy force effect under local thermal non-equilibrium conditions.

Design/methodology/approach

The governing equations for the nanofluid and solid phase are discretized by the finite volume method and the SIMPLE algorithm is used to solve these equations.

Findings

It is observed that there is an increase in a local variation of temperature along the upper wall with increasing Reynolds, Darcy and Grashof numbers. For given parameters, the optimum values of thermal conductivity ratio and porous layer thickness leading to better heating on the upper wall are found as K_r = 1.0 and S = 0.5, respectively. The maximum and minimum values of temperature on the upper wall are obtained in the case of higher nanoparticle volume fraction at Re = 100, however, the temperature values get higher along the upper wall with increasing nanoparticle volume fraction at Re = 300.

Originality/value

The effects of various parameters, such as Reynolds number, Darcy number and Grashof number, on thermal behavior and nanofluid flow are examined to determine the desirable heating conditions for the upper wall. This paper provides a solution to problems such as icing on the surface with a suitable thermal design and optimum geometric configuration.

中文翻译：

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在多孔层存在下具有恒定热通量的冷却表面的纳米流体射流冲击加热

目的

本研究的目的是数值研究在多孔层存在下具有均匀热通量的冷却表面的受限单壁碳纳米管-水纳米流体射流冲击加热。介绍了考虑局部热非平衡条件下浮力效应的对流传热机理分析。

设计/方法/方法

纳米流体和固相的控制方程通过有限体积法离散化，并使用 SIMPLE 算法求解这些方程。

发现

观察到随着雷诺数、达西数和格拉肖夫数的增加，沿上壁的局部温度变化增加。对于给定的参数，热导率和多孔层厚度的最佳值分别为K _r = 1.0 和 S = 0.5，导致上壁更好的加热。上壁温度的最大值和最小值是在 Re = 100 时纳米颗粒体积分数较高的情况下获得的，然而，随着纳米颗粒体积分数的增加，上壁温度值在 Re = 300 时升高。

原创性/价值

检查各种参数（例如雷诺数、达西数和格拉肖夫数）对热行为和纳米流体流动的影响，以确定上壁所需的加热条件。本文通过合适的热设计和最佳几何配置提供了解决表面结冰等问题的方法。