Abo Bibliothek: Guest

ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Combined gas radiation and laminar mixed convection in vertical concentric annuli

Get access (open in a dialog) DOI: 10.1615/IHTC12.5020
6 pages

Abstrakt

Numerical calculations are performed to study radiation effects on simultaneously developing laminar mixed convection flow and heat transfer for real gaseous H2O-CO2 mixtures in vertical concentric annuli. The non-gray behavior of gas radiative properties and the axial propagation of radiation are taken into account in the analysis. The flow equations and energy balance equation are solved simultaneously with temperature dependent fluid properties. The approximations of a boundary layer flow are made except for radiative transfer. We apply a numerical method which is able to transform the elliptic problem to a series of parabolic ones where the marching solution can be used. This procedure applies for sufficiently high Reynolds numbers preventing locally reversed flow. The radiative properties of the flowing gas mixture are modeled by using the Absorption Distribution Function (ADF) model. A discrete-direction method is applied to solve the geometrical part of the radiative transfer problem. It is shown that radiative transfer, besides its direct contribution to heat transfer, affects significantly the velocity profiles, and thus, the conductive heat transfer at the walls.