Title: The effect of the conjugate-conduction parameter and Prandtl number on the free convective couple stress fluid flow over a vertical cylinder

Authors: H.P. Rani; G. Janardhana Reddy; Chang Nyung Kim

Addresses: Department of Mathematics, National Institute of Technology, Warangal-506004, AP, India ' Department of Mathematics, National Institute of Technology, Warangal-506004, AP, India ' Department of Mechanical Engineering, College of Advanced Technology, Industrial Liaison Research Institute, Kyung Hee University, Gyeonggi-do 446-701, Korea

Abstract: Numerical analysis is performed to study the conjugate heat transfer effects on the transient free convective couple stress fluid flow over a vertical slender hollow circular cylinder with the inner surface at a constant temperature. A set of non-dimensional governing equations namely, the continuity, momentum and energy equations is derived and these equations are unsteady non-linear and coupled. An unconditionally stable Crank-Nicolson type of implicit finite difference scheme is employed to obtain the discretised forms of governing equations. These equations are solved using the Thomas and pentadiagonal algorithms. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. Transient velocity and temperature profiles, average skin-friction coefficient (Cf) and average Nusselt number (Nu) are shown graphically. In all these profiles it is observed that the time required for the variables to reach the steady-state increases with the increasing values of conjugate-conduction parameter (P) and Prandtl number. In the vicinity of the hot wall, the velocity and temperature of the fluid decrease as P increases. It is noticed that the steady-state values of Cf and Nu decreases as P increases.

Keywords: conjugate heat transfer; CHT; couple stress fluids; natural convection; slender hollow cylinders; finite difference method; FDM; Prandtl number; free convection; fluid flow; vertical cylinders.

DOI: 10.1504/PCFD.2014.064553

Progress in Computational Fluid Dynamics, An International Journal, 2014 Vol.14 No.5, pp.316 - 327

Published online: 27 Sep 2014 *

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