Title: Viscous dissipation effects on entropy generation in heated vertical parallel-plate channels for mixed convection

Authors: Ugur Akbulut; Rasim Volga Ovali; Haydar Kucuk

Addresses: Faculty of Engineering, Department of Mechanical Engineering, Recep Tayyip Erdogan University, 53100 Rize, Turkey ' Faculty of Engineering, Department of Nanotechnology Engineering, Recep Tayyip Erdogan University, 53100 Rize, Turkey ' Faculty of Engineering, Department of Mechanical Engineering, Recep Tayyip Erdogan University, 53100 Rize, Turkey

Abstract: In this study, effect of viscous dissipation on entropy generation for fully developed incompressible laminar flow mixed convection in vertical parallel-plate channels with asymmetric and symmetric uniform heat fluxes was parametrically analysed. Analytical equations were derived by using continuum approach and perturbation method. A specific MATLAB code was created to solve the governing equations. The effects of Gr/Re, the Brinkman number, and the ratio of wall heat flux on the entropy generation are presented and discussed. It is concluded that viscous dissipation has a significant effect on the entropy generation for mixed convection in heated vertical parallel-plate channels. Entropy generation resulting from fluid friction goes up, however, entropy generation due to heat transfer decreases by increasing of viscous dissipation. Consequently, it can be said that, this study will contribute to literature in optimising the systems that operates under mixed convection conditions in the vertical parallel-plate configuration.

Keywords: entropy generation; viscous dissipation; mixed convection; vertical parallel-plate channel; perturbation method.

DOI: 10.1504/IJEX.2017.084532

International Journal of Exergy, 2017 Vol.23 No.1, pp.1 - 17

Received: 28 Jul 2016
Accepted: 04 Jan 2017
Published online: 12 Jun 2017 *

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