Natural convection combined with thermal radiation in a square cavity filled with a viscoelastic fluid

Abstract

Purpose

The purpose of this paper is to study natural convective heat transfer and viscoelastic fluid flow in a differentially heated square cavity under the effect of thermal radiation.

Design/methodology/approach

The cavity filled with a viscoelastic fluid is heated uniformly from the left wall and cooled from the right side while insulated from horizontal walls. Governing partial differential equations formulated in non-dimensional stream function, vorticity and temperature with corresponding boundary conditions have been solved by finite difference method of second order accuracy. The effects of Rayleigh number (Ra = 1e+3−1e+5), radiation parameter (R_d = 0 − 10), Prandtl number (Pr = 1 − 30) and elastic number (E = 0.0001 − 0.001) on flow patterns, temperature fields, average Nusselt number at hot vertical wall and rate of fluid flow have been studied.

Findings

It has been found that a growth of elastic number leads to the heat transfer reduction and convective flow attenuation. The heat conduction is a dominating heat transfer mechanism for high values of radiation parameter.

Originality/value

The originality of this work is to analyze heat transfer and fluid flow of a viscoelastic fluid inside a differentially heated cavity. The results would benefit scientists and engineers to become familiar with the flow and heat behavior of non-Newtonian fluids, and the way to predict the properties of this flow for possibility of using viscoelastic fluids in compact heat exchangers, electronic cooling systems, polymer engineering, etc.

Citation

Sheremet, M.A. and Pop, I. (2018), "Natural convection combined with thermal radiation in a square cavity filled with a viscoelastic fluid", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 28 No. 3, pp. 624-640. https://doi.org/10.1108/HFF-02-2017-0059