Purpose

This paper aims to study the effect of concentric hot circular cylinder inside egg-cavity porous-copper nanofluid on natural convection phenomena.

Design/methodology/approach

The finite element method–based Galerkin approach is applied to solve numerically the set of governing equations with appropriate boundary conditions.

Findings

The effects of different range parameters, such as Darcy number (10–3 = Da = 10–1), Rayleigh number (103 = Ra = 106), nanoparticle volume fraction (0 = ϑ = 0.06) and eccentricity (−0.3 = e = 0.1) on the fluid flow represent by stream function and heat transfer represent by temperature distribution, local and average Nusselt numbers.

Research limitations/implications

A comparison between oval shape and concentric circular concentric cylinder was investigated.

Originality/value

In the current numerical study, heat transfer by natural convection was identified inside the new design of egg-shaped cavity as a result of the presence of a circular inside it supported by a porous medium filled with a nanofluid. After reviewing previous studies and considering the importance of heat transfer by free convection inside tubes for many applications, to the best of the authors’ knowledge, the current work is the first study that deals with a study and comparison between the common shape (concentric circular tubes) and the new shape (egg-shaped cavity).

中文翻译：

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不同偏心率椭圆形多孔腔内热同心圆柱体纳米流体自然对流

 目的

本文旨在研究蛋腔多孔铜纳米流体内同心热圆柱体对自然对流现象的影响。

设计/方法论/途径

应用基于有限元法的伽辽金方法对具有适当边界条件的控制方程组进行数值求解。

 发现

不同范围参数的影响，例如达西数 (10–3 = Da = 10–1)、瑞利数 (103 = Ra = 106)、纳米颗粒体积分数 (0 = ϑ = 0.06) 和偏心率 (−0.3 = e) = 0.1) 流体流动由流函数表示，传热由温度分布、局部和平均努塞尔数表示。

研究局限性/影响

研究了椭圆形和同心圆同心圆柱体之间的比较。

 原创性/价值

在当前的数值研究中，由于蛋形腔内部存在由填充纳米流体的多孔介质支撑的圆形结构，因此在新设计的蛋形腔内发现了自然对流传热。在回顾了以前的研究并考虑了管内自由对流传热对于许多应用的重要性之后，据作者所知，当前的工作是第一项研究和比较常见形状（同心圆形）的研究。管）和新形状（蛋形腔）。