Hydromagnetic Stability of Metallic Nanofluids (Cu-Water and Ag-Water) Using Darcy-Brinkman Model

IF 1 Q3 GEOCHEMISTRY & GEOPHYSICS
J. Ahuja, U. Gupta, R. K. Wanchoo
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引用次数: 5

Abstract

Thermal convection of a nanofluid layer in the presence of imposed vertical magnetic field saturated by a porous medium is investigated for both-free, rigid-free, and both-rigid boundaries using Darcy-Brinkman model. The effects of Brownian motion and thermophoretic forces due to the presence of nanoparticles and Lorentz’s force term due to the presence of magnetic field have been considered in the momentum equations along with Maxwell’s equations. Keeping in mind applications of flow through porous medium in geophysics, especially in the study of Earth’s core, and the presence of nanoparticles therein, the hydromagnetic stability of a nanofluid layer in porous medium is considered in the present formulation. An analytical investigation is made by applying normal mode technique and Galerkin type weighted residuals method and the stability of Cu-water and Ag-water nanofluids is compared. Mode of heat transfer is through stationary convection without the occurrence of oscillatory motions. Stability of the system gets improved appreciably by raising the Chandrasekhar number as well as Darcy number whereas increase in porosity hastens the onset of instability. Further, stability of the system gets enhanced as we proceed from both-free boundaries to rigid-free and to both-rigid boundaries.
基于Darcy-Brinkman模型的金属纳米流体(Cu-Water和Ag-Water)的磁稳定性
利用Darcy-Brinkman模型研究了在垂直磁场饱和的多孔介质中,纳米流体层在无、无刚性和双刚性边界下的热对流。在动量方程和麦克斯韦方程中,考虑了纳米粒子的存在引起的布朗运动和热泳力的影响以及磁场引起的洛伦兹力项的影响。考虑到多孔介质流动在地球物理学中的应用,特别是在地核研究中的应用,以及其中纳米颗粒的存在,本公式考虑了多孔介质中纳米流体层的磁稳定性。应用正模技术和伽辽金加权残差法对铜水纳米流体和银水纳米流体的稳定性进行了分析研究。传热方式是通过静止对流而不发生振荡运动。提高钱德拉塞卡数和达西数可以显著改善体系的稳定性,而孔隙度的增加则会加速不稳定性的发生。进一步地,当我们从两自由边界到无刚性边界和两刚性边界时,系统的稳定性得到增强。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
International Journal of Geophysics
International Journal of Geophysics GEOCHEMISTRY & GEOPHYSICS-
CiteScore
1.50
自引率
0.00%
发文量
12
审稿时长
21 weeks
期刊介绍: International Journal of Geophysics is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles in all areas of theoretical, observational, applied, and computational geophysics.
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