Onset of double-diffusive convection of a sparsely packed micropolar fluid in a porous medium layer saturated with a nanofluid

Jawali C. Umavathi, Mikhail A. Sheremet

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The onset of convection of a sparsely packed micropolar fluid in a porous medium layer saturated by a nanofluid is examined by using a linear and nonlinear stability analyses. The Darcy–Brinkman–Forchheimer model is employed for the porous medium layer. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The critical Rayleigh number, wave number for stationary and oscillatory modes and frequency of oscillations are obtained analytically using linear theory, and the nonlinear analysis is made with minimal representation of the truncated Fourier series analysis involving only two terms. The effect of various parameters on the stationary and oscillatory convections is shown pictorially. The dependence of stationary or oscillatory convection on the porous parameter and parameters involved in micropolar fluids is also discussed. We also study the effect of time on transient Nusselt number and Sherwood number which are found to be oscillatory when time is small. However, when time becomes very large, both the transient Nusselt value and Sherwood value approach to their steady-state values.

Original languageEnglish
Article number128
JournalMicrofluidics and Nanofluidics
Volume21
Issue number7
DOIs
Publication statusPublished - 1 Jul 2017

Fingerprint

micropolar fluids
Porous materials
convection
Fluids
Thermophoresis
thermophoresis
Brownian movement
Fourier series
Nonlinear analysis
Rayleigh number
Nusselt number
oscillations
Convection

Keywords

  • Darcy–Brinkman–Forchheimer model
  • Micropolar fluids
  • Porous medium
  • Rayleigh–Benard convection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry

Cite this

@article{15e36e3db59f45e4a10fa2c0ebec11fc,
title = "Onset of double-diffusive convection of a sparsely packed micropolar fluid in a porous medium layer saturated with a nanofluid",
abstract = "The onset of convection of a sparsely packed micropolar fluid in a porous medium layer saturated by a nanofluid is examined by using a linear and nonlinear stability analyses. The Darcy–Brinkman–Forchheimer model is employed for the porous medium layer. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The critical Rayleigh number, wave number for stationary and oscillatory modes and frequency of oscillations are obtained analytically using linear theory, and the nonlinear analysis is made with minimal representation of the truncated Fourier series analysis involving only two terms. The effect of various parameters on the stationary and oscillatory convections is shown pictorially. The dependence of stationary or oscillatory convection on the porous parameter and parameters involved in micropolar fluids is also discussed. We also study the effect of time on transient Nusselt number and Sherwood number which are found to be oscillatory when time is small. However, when time becomes very large, both the transient Nusselt value and Sherwood value approach to their steady-state values.",
keywords = "Darcy–Brinkman–Forchheimer model, Micropolar fluids, Porous medium, Rayleigh–Benard convection",
author = "Umavathi, {Jawali C.} and Sheremet, {Mikhail A.}",
year = "2017",
month = "7",
day = "1",
doi = "10.1007/s10404-017-1965-9",
language = "English",
volume = "21",
journal = "Microfluidics and Nanofluidics",
issn = "1613-4982",
publisher = "Springer Verlag",
number = "7",

}

TY - JOUR

T1 - Onset of double-diffusive convection of a sparsely packed micropolar fluid in a porous medium layer saturated with a nanofluid

AU - Umavathi, Jawali C.

AU - Sheremet, Mikhail A.

PY - 2017/7/1

Y1 - 2017/7/1

N2 - The onset of convection of a sparsely packed micropolar fluid in a porous medium layer saturated by a nanofluid is examined by using a linear and nonlinear stability analyses. The Darcy–Brinkman–Forchheimer model is employed for the porous medium layer. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The critical Rayleigh number, wave number for stationary and oscillatory modes and frequency of oscillations are obtained analytically using linear theory, and the nonlinear analysis is made with minimal representation of the truncated Fourier series analysis involving only two terms. The effect of various parameters on the stationary and oscillatory convections is shown pictorially. The dependence of stationary or oscillatory convection on the porous parameter and parameters involved in micropolar fluids is also discussed. We also study the effect of time on transient Nusselt number and Sherwood number which are found to be oscillatory when time is small. However, when time becomes very large, both the transient Nusselt value and Sherwood value approach to their steady-state values.

AB - The onset of convection of a sparsely packed micropolar fluid in a porous medium layer saturated by a nanofluid is examined by using a linear and nonlinear stability analyses. The Darcy–Brinkman–Forchheimer model is employed for the porous medium layer. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The critical Rayleigh number, wave number for stationary and oscillatory modes and frequency of oscillations are obtained analytically using linear theory, and the nonlinear analysis is made with minimal representation of the truncated Fourier series analysis involving only two terms. The effect of various parameters on the stationary and oscillatory convections is shown pictorially. The dependence of stationary or oscillatory convection on the porous parameter and parameters involved in micropolar fluids is also discussed. We also study the effect of time on transient Nusselt number and Sherwood number which are found to be oscillatory when time is small. However, when time becomes very large, both the transient Nusselt value and Sherwood value approach to their steady-state values.

KW - Darcy–Brinkman–Forchheimer model

KW - Micropolar fluids

KW - Porous medium

KW - Rayleigh–Benard convection

UR - http://www.scopus.com/inward/record.url?scp=85023208824&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85023208824&partnerID=8YFLogxK

U2 - 10.1007/s10404-017-1965-9

DO - 10.1007/s10404-017-1965-9

M3 - Article

VL - 21

JO - Microfluidics and Nanofluidics

JF - Microfluidics and Nanofluidics

SN - 1613-4982

IS - 7

M1 - 128

ER -