Hybrid Nanofluid Flow Past a Permeable Moving Thin Needle

Iskandar Waini,Anuar Ishak,Ioan Pop

doi:10.3390/math8040612

Abstract

The problem of a steady flow and heat transfer past a permeable moving thin needle in a hybrid nanofluid is examined in this study. Here, we consider copper (Cu) and alumina (Al2O3) as hybrid nanoparticles, and water as a base fluid. In addition, the effects of thermophoresis and Brownian motion are taken into consideration. A similarity transformation is used to obtain similarity equations, which are then solved numerically using the boundary value problem solver, bvp4c available in Matlab software (Matlab_R2014b, MathWorks, Singapore). It is shown that heat transfer rate is higher in the presence of hybrid nanoparticles. It is discovered that the non-uniqueness of the solutions is observed for a certain range of the moving parameter λ . We also observed that the bifurcation of the solutions occurs in the region of λ < 0 , i.e., when the needle moved toward the origin. Furthermore, we found that the skin friction coefficient and the heat transfer rate at the surface are higher for smaller needle sizes. A reduction in the temperature and nanoparticle concentration was observed with the increasing of the thermophoresis parameter. It was also found that the increase of the Brownian motion parameter leads to an increase in the nanoparticle concentration. Temporal stability analysis shows that only one of the solutions was stable and physically reliable as time evolved.

Highlights

The development of advanced heat transfer fluids has received considerable coverage from the researchers and scientists over the last few years
This study aims to examine the flow past a permeable moving thin needle in a hybrid nanofluid by employing Tiwari and Das [35] and Buongiorno [36] nanofluid models
The present results revealed that the added hybrid nanoparticles led to the increment of the heat transfer rate

Summary

Introduction

The development of advanced heat transfer fluids has received considerable coverage from the researchers and scientists over the last few years. Regular fluids (ethylene glycol, oil, water) are commonly used in the industrial and engineering applications. The heat transfer rate of these fluids is limited due to weak thermal conductivity. To resolve its deficiency, a single form of nanosized particles is applied to the above-mentioned fluids and is called ‘nanofluid’. This term was introduced by Choi and Eastman [1] for the first time in 1995. The advantages of utilizing nanofluids filled in a rectangular enclosure have been examined by Khanafer et al [2] and

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