0
Research Papers: Natural and Mixed Convection

Natural Convective Boundary Layer Flow of Nanofluids Above an Isothermal Horizontal Plate

[+] Author and Article Information
Kaustav Pradhan

Mechanical Engineering Department,
Indian Institute of Technology Kharagpur,
Kharagpur 721302, India
e-maiil: pradhan.kaustav@gmail.com

Subho Samanta

Mechanical Engineering Department,
Indian Institute of Technology Kharagpur,
Kharagpur 721302, India
e-mail: subhosamanta@iitkgp.ac.in

Abhijit Guha

Professor
Mechanical Engineering Department,
Indian Institute of Technology Kharagpur,
Kharagpur 721302, India
e-mail: a.guha@mech.iitkgp.ernet.in

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received July 4, 2013; final manuscript received June 20, 2014; published online July 29, 2014. Assoc. Editor: Ali Ebadian.

J. Heat Transfer 136(10), 102501 (Jul 29, 2014) (8 pages) Paper No: HT-13-1338; doi: 10.1115/1.4027909 History: Received July 04, 2013; Revised June 20, 2014

The natural convective boundary layer flow of a nanofluid over an isothermal horizontal plate is studied analytically. The model used for the nanofluid accounts for the effects of Brownian motion and thermophoresis. The analysis shows that the velocity, temperature, and nanoparticle volume fraction profiles in the respective boundary layers depend not only on the Prandtl number (Pr) and Lewis number (Le) but also on three additional dimensionless parameters: the Brownian motion parameter Nb, the buoyancy ratio parameter Nr and the thermophoresis parameter Nt. The velocity, temperature, and nanoparticle volume fraction profiles for the nanofluid are found to have a weak dependence on the values of Nb, Nr, and Nt. The effect of the above-mentioned parameters on the local skin-friction coefficient and Nusselt number has been studied extensively. It has been observed that as Nr increases, the local skin-friction coefficient decreases whereas local Nusselt number remains almost constant. As Nb or Nt increases, the local skin-friction coefficient increases whereas the local Nusselt number decreases.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Physical model and the coordinate system

Grahic Jump Location
Fig. 4

Variation of f ′(η) which determines the dimensionless longitudinal velocity for two values of Nr at Pr=7, Le=10, and Nb=Nt=0.5. (Keys: ———— Nr=10-5, – – – – – Nr=0.5.)

Grahic Jump Location
Fig. 5

Variation of θ(η) which determines the temperature distribution of the nanofluid for two values of Nb and Nt at Pr=7, Le=10, and Nr=0.5. (Keys: ———— Nb=Nt=10-5, – – – – – Nb=Nt=0.5.)

Grahic Jump Location
Fig. 6

Variation of ζ(η) which determines the nanoparticle volume fraction in the nanofluid for two values of Nb and Nt, at Pr=7, Nr=0.5 and two values of Lewis numbers. (Keys: ———— Nb=Nt=10-5, – – – – – Nb=Nt=0.5.)

Grahic Jump Location
Fig. 2

Plots of the dimensionless similarity functions f(η), f'(η), θ(η), and ζ(η) for Pr=7, Nr=Nb=Nt=0.5 and Le=10. These represent the stream function, longitudinal velocity, temperature, and nanoparticle volume fraction, respectively. (Keys: ———— f(η), – – – – – f'(η), – · – · – · θ(η), ................ ζ(η).)

Grahic Jump Location
Fig. 3

Plots of the dimensionless similarity functions f'(η), θ(η), and ζ(η) for Pr=7, Nr=Nb=Nt=0.5 and two values of the Lewis number: (a) Le=10 and (b) Le=100. These represent the longitudinal velocity, temperature, and nanoparticle volume fraction, respectively. (Keys: ———— f'(η), – – – – – θ(η), – · – · – · ζ(η).)

Grahic Jump Location
Fig. 7

Variation of the reduced local Nusselt number with the Brownian motion parameter for Pr=7, Le=10 and three values of Nr and Nt

Grahic Jump Location
Fig. 8

Variation of the reduced local Nusselt number with the thermophoretic parameter for Pr=7, Le=10 and three values of Nr and Nb

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In