## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Effect of radiation on the flow structure and heat transfer in a two-dimensional gray medium

**ABSTRACT**

A numerical study of combined natural convection and radiation in a square cavity filled with a gray non-scattering semi-transparent fluid is conducted. The horizontal walls are adiabatic and the vertical are differentially heated. Convection is treated by the finite volumes approach and the discrete ordinate method is used to solve radiative transfer equation using S6 order of angular quadrature. Representative results illustrating the effects of the Rayleigh number, the optical thickness and the Planck number on the flow and temperature distribution are reported. In addition, the results in terms of the average Nusselt number obtained for various parametric conditions show that radiation modifies significantly the thermal behavior of the fluid within the enclosure.

**KEYWORDS**

PAPER SUBMITTED: 2018-01-08

PAPER REVISED: 2018-03-01

PAPER ACCEPTED: 2018-03-12

PUBLISHED ONLINE: 2018-04-28

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