Numerical Simulation of Turbulent Natural Convection and Gas Radiation in Differentially Heated Tall Cavities Using Discrete Ordinates Method

DOI: 10.1615/ICHMT.2006.TurbulHeatMassTransf.1120
pages 535-538

R. Capdevila
Centre Tecnològic de Transferència de Calor (CTTC), Lab. Termotècnia i Energètica, Universitat Politècnica de Catalunya (UPC), C/Colom, 11, E08222 Terrassa, Spain

C. D. Perez-Segarra
Heat and Mass Transfer Technological Center (CTTC) Universitat Politecnica de Catalunya - BarcelonaTech (UPC) Colom 11, 08222 Terrassa, Barcelona, Spain

G. Colomer
Termo Fluids S.L, Centre Tecnològic de Transferència de Calor (CTTC), Lab. Termotècnia i Energètica, Universitat Politècnica de Catalunya (UPC), C/Colom, 11, E08222 Terrassa, Spain

Assensi Oliva
Centre Tecnologic de Transferencia de Calor (CTTC), Universitat Politecnica de Catalunya (UPC), Colom 11, 08222 Terrassa, Barcelona, Spain

Abstract

Turbulent natural convection and radiation in two different differentially heated cavities have been studied. The first case corresponds to a tall cavity of 28.6:1 aspect ratio and 1.92 · 10¹⁰ Rayleigh number. The second case is a cavity of aspect ratio 5:1 with a Rayleigh number of 4.48 · 10¹⁰. Both simulations are compared with experimental data available in the literature. Cases taking into account only surface radiation (non-participating medium) have been modelled using the Radiosity -Irradiosity Method (RIM) and cases that include both, surface and gas radiation (participating medium), have been simulated using the Discrete Ordinates Method (DOM). The turbulent flow is described by the time averaged Navier-Stokes equations. Turbulent stresses and heat fluxes are predicted with two low Reynolds number two-equation eddy-viscosity turbulent models, k − ε and k − ω. The influence of radiation on the phenomenological aspects of the case has been analysed.