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MHD Transient Free Convection Flow in Vertical Concentric Annulus with Isothermal and Adiabatic Boundaries
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MHD Transient Free Convection Flow in Vertical Concentric Annulus with Isothermal and Adiabatic Boundaries

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Abstract:

This paper presents MHD transient flow in an infinite vertical concentric annulus when the fluid is set in motion by free convection current occurring in the annulus as a result of application of isothermal heating on the inner surface of the outer cylinder while the outer surface of the inner cylinder is thermally insulated. The solution of the governing equations are obtained using the well-known Laplace transform technique while the Riemann-sum approximation method has been used to invert the solution from Laplace domain to time domain. The numerical values obtained using Riemann-sum approximation approach is validated by presenting a comparison with the values obtained using the implicit finite difference method as well as the steady-state solution. These comparisons with the steady state solution shows a remarkable agreement at large value of time. The effect of the governing parameters on the velocity field, temperature field, mass flow rate as well as the skin-friction on both surfaces of the annulus have been analysed and presented with the aid of line graph. Generally, we observed that the mass flow rate and skin friction at the isothermally heated surface increases with increase in radius ratio. However, the reverse is seen at the thermally insulated surface as the skin-friction decreases with increase in radius ratio.

Info:

Periodical:
International Journal of Engineering and Technologies (Volume 11)
Pages:
40-52
DOI:
https://doi.org/10.18052/www.scipress.com/IJET.11.40
Citation:
B. K. Jha and T. S. Yusuf, "MHD Transient Free Convection Flow in Vertical Concentric Annulus with Isothermal and Adiabatic Boundaries", International Journal of Engineering and Technologies, Vol. 11, pp. 40-52, 2017
Online since:
July 2017
Authors:
Basant K. Jha, Taiwo S. Yusuf
Keywords:
Adiabatic, Free Convective Flow, Hartmann Number, Isothermal, MHD, Riemann-Sum Approximation, Transient
Export:
RIS, BibTeX, Text
Distribution:
Open Access

Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0 International License

References:

[1] P. Chandran, N.C. Sacheti, A.K. Singh, A unified approach to analytical solution of a hydromagnetic free convection flow, Scientiae Mathematicae Japonicae. 4 (2001) 459-468.

[2] A. Kumar, A.K. Singh, Effect of induced magnetic field on natural convection in vertical concentric annuli heated/cooled asymmetrically, Journal of Applied Fluid Mechanics. 6(1) (2013) 15-26.

[3] M. A. Al- Nimr, T. Darabseh, Analytical solution for transient laminar fully developed free convection in open-ended vertical concentric porous annuli, J. Heat Transfer. 117(3) (1995) 762-765.

DOI: https://doi.org/10.1115/1.2822643

[4] B.K. Jha, C.A. Apere, Unsteady MHD Couette flow in an annuli, the Riemann-sum approximation approach, Journal of the Physical Society of Japan. 79(12) (2010) 124403.

DOI: https://doi.org/10.1143/jpsj.79.124403

[5] B.K. Jha, A.O. Ajibade, Transient natural convection flow between vertical parallel plates: one plate isothermally heated and the other thermally insulated, Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering. 224(4) (2010).

DOI: https://doi.org/10.1243/09544089jpme319

[6] B.K. Jha, B. Aina, I. Sani, Fully developed MHD natural convection flow in a vertical annular micro-channel: An exact solution, Journal of King Saud University-Science. 27(3) (2014) 253-259.

DOI: https://doi.org/10.1016/j.jksus.2014.12.002

[7] B.C. Prasannakumara, B.J. Gireesha, P.T. Manjunatha, Melting phenomenon in MHD stagnation point flow of dusty fluid over a stretching sheet in the presence of thermal radiation and non-uniform heat source/sink, International Journal for Computational Methods in Engineering Science and Mechanics. 16(5) (2015).

DOI: https://doi.org/10.1080/15502287.2015.1047056

[8] M. R. Krishnamurthy et al., Effect of chemical reaction on MHD boundary layer flow and melting heat transfer of Williamson nanofluid in porous medium, Engineering Science and Technology, an International Journal. 19(1) (2015) 53-61.

DOI: https://doi.org/10.1016/j.jestch.2015.06.010

[9] B.K. Jha, A.O. Ajibade, Unsteady free-convective Couette flow having isothermal and adiabatic boundaries, Int. J. of Energy and Tech. 2(22) (2010) 1-7.

[10] R. V. Churchill, Operational mathematics, 2nd edition, McGraw-Hill, NewYork, (1958).

[11] B.K. Jha, T.S. Yusuf, Transient free convective flow in an annular porous medium: A semi-analytical approach, Engineering Science and Technology, an International Journal. 19(4) (2016) 1936-(1948).

DOI: https://doi.org/10.1016/j.jestch.2016.09.022

[12] D.Y. Tzou, Macro to microscale heat transfer: The lagging behavior, Taylor and Francis, London, (1997).

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