Purpose

This paper aims to study numerically the non-Newtonian solution of carboxymethyl cellulose in water along with copper oxide nanoparticles, which flow turbulently through twisted smooth and finned tubes.

Design/methodology/approach

The twisted-tape inserts of rectangular and triangular sections are investigated under constant wall heat flux and the nanoparticle concentration varies between 0% and 1.5%. Computational fluid dynamics simulation is first validated by experimental information from two test cases, showing that the numerical results are in good agreement with previous studies. Here, the impact of nanoparticle concentration, tube twist and fins shape on the heat transfer and pressure loss of the system is measured. It is accomplished using longitudinal rectangular and triangular fins in a wide range of prominent parameters.

Findings

The results show that first, both the Nusselt number and friction factor increase with the rise in the concentration of nanoparticles and twist of the tube. Second, the trend is repeated by adding fins, but it is more intense in the triangular cases. The tube twist increases the Nusselt number up to 9%, 20% and 46% corresponding to smooth tube, rectangular and triangular fins, respectively. The most twisted tube with triangular fins and the highest value of concentration acquires the largest performance evaluation criterion at 1.3, 30% more efficient than the plain tube with 0% nanoparticle concentration.

Originality/value

This study explores an innovative approach to enhancing heat transfer in a non-Newtonian nanofluid flowing through an oval tube. The use of twisted-tape inserts with rectangular and triangular sections in this specific configuration represents a novel method to improve fluid flow characteristics and heat transfer efficiency. This study stands out for its originality in combining non-Newtonian fluid dynamics, nanofluid properties and geometric considerations to optimize heat transfer performance. The results of this work can be dramatically considered in advanced heat exchange applications.

中文翻译：

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CMC/CuO 非牛顿纳米流体湍流进入椭圆形管的矩形和三角形截面的扭曲带插件

 目的

本文旨在数值研究羧甲基纤维素在水中的非牛顿溶液以及氧化铜纳米颗粒，这些纳米颗粒湍流通过扭曲的光滑和翅片管。

设计/方法/方法

在恒定壁热通量下研究了矩形和三角形截面的扭曲带嵌件，纳米颗粒浓度在 0% 到 1.5% 之间变化。首先通过两个测试用例的实验信息验证了计算流体动力学模拟，表明数值结果与以前的研究吻合较好。在这里，测量了纳米颗粒浓度、管扭曲和翅片形状对系统传热和压力损失的影响。它是使用具有各种突出参数的纵向矩形和三角形翅片实现的。

 发现

结果表明：首先，努塞尔数和摩擦因子都随着纳米颗粒浓度的增加和管材的扭曲而增加。其次，通过添加鳍片来重复这种趋势，但在三角形情况下更为强烈。管扭曲使努塞尔数增加高达 9%、20% 和 46%，分别对应于光滑管、矩形和三角形翅片。具有三角形翅片和最高浓度值的最大扭曲管在 1.3 处获得最大的性能评价标准，比纳米颗粒浓度为 0% 的光管效率高 30%。

 原创性/价值

本研究探索了一种创新方法，以增强流经椭圆形管的非牛顿纳米流体中的传热。在这种特定配置中使用矩形和三角形截面的扭曲带插件代表了一种改善流体流动特性和传热效率的新方法。这项研究在结合非牛顿流体动力学、纳米流体特性和几何考虑以优化传热性能方面的独创性而脱颖而出。这项工作的结果可以在高级热交换应用中得到充分的考虑。