Futures and Trends Research Group, Faculty of Industrial Science and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, UMP Kuantan, Pahang, Malaysia.
Basic Engineering Sciences Department, College of Engineering Majmaah University, Majmaah, 11952, Saudi Arabia.
Sci Rep. 2017 May 26;7(1):2445. doi: 10.1038/s41598-017-01358-3.
This article investigates heat transfer enhancement in free convection flow of Maxwell nanofluids with carbon nanotubes (CNTs) over a vertically static plate with constant wall temperature. Two kinds of CNTs i.e. single walls carbon nanotubes (SWCNTs) and multiple walls carbon nanotubes (MWCNTs) are suspended in four different types of base liquids (Kerosene oil, Engine oil, water and ethylene glycol). Kerosene oil-based nanofluids are given a special consideration due to their higher thermal conductivities, unique properties and applications. The problem is modelled in terms of PDE's with initial and boundary conditions. Some relevant non-dimensional variables are inserted in order to transmute the governing problem into dimensionless form. The resulting problem is solved via Laplace transform technique and exact solutions for velocity, shear stress and temperature are acquired. These solutions are significantly controlled by the variations of parameters including the relaxation time, Prandtl number, Grashof number and nanoparticles volume fraction. Velocity and temperature increases with elevation in Grashof number while Shear stress minimizes with increasing Maxwell parameter. A comparison between SWCNTs and MWCNTs in each case is made. Moreover, a graph showing the comparison amongst four different types of nanofluids for both CNTs is also plotted.
本文研究了在常壁温下垂直静止平板上碳纳米管（CNTs）增强 Maxwell 纳米流体的自然对流传热。将两种类型的 CNTs，即单壁碳纳米管（SWCNTs）和多壁碳纳米管（MWCNTs）悬浮在四种不同的基液（煤油、发动机油、水和乙二醇）中。由于煤油基纳米流体具有更高的热导率、独特的性质和应用，因此特别考虑了它们。该问题以 PDE 及其初始和边界条件建模。为了将控制问题转化为无量纲形式，插入了一些相关的无量纲变量。利用拉普拉斯变换技术求解得到的问题，并获得了速度、剪切应力和温度的精确解。这些解主要受松弛时间、普朗特数、格拉肖夫数和纳米颗粒体积分数等参数的变化控制。速度和温度随格拉肖夫数的增加而增加，而剪切应力随麦克斯韦参数的增加而减小。在每种情况下都比较了 SWCNTs 和 MWCNTs。此外，还绘制了一张图，显示了两种 CNTs 四种不同纳米流体之间的比较。
