Coupled thermal radiation and natural convection heat transfer in a cavity with a discretely heated inner body

Abstract

The natural convection coupled to surface radiation in an asymmetrically cooled square cavity including a partially heated inner circular cylinder is numerically simulated in this paper following the finite volume and the discrete ordinate methods. The flow inside the cavity is driven by the heated part of the circular cylinder maintained at high temperature 297K≤TH≤357K. The cavity is filled with the air (Pr=0.71) cooled by a single vertical wall maintained at a cold temperature TC=293K. The other portion of the inner circular cylinder and the remaining boundaries of the enclosure are insulated. The hydrodynamic and the thermal behavior of the fluid, the convective and the radiative heat transfer are investigated for Rayleigh number ranging from 103 to 107and the common emissivity 0≤ε≤1 of the inner and outer surfaces. The numerical work is carried out using an in-house CFD code. The obtained results show a considerable effect of the surface radiation on the flow structure and heat transfer characteristics in the cavity.