Three dimensional simulation of convection and radiation in a cubic cavity

The main objective of this study is to investigate thephenomenon of radiation and natural convection in bothtransparent and participating media in a three-dimensionaldifferentially heated cavity. The radiative transfer equationwas solved using the discrete ordinates method .The Navier–Stokes equations, proposed for natural convection, weresolved using a segregated SIMPLE-like algorithm. For nonparticipatingmedia, the coupling between the radiativetransfer and Navier–Stokes equations was carried out via theradiative heat exchange between surfaces. For participatingmedia, a source term is added in the energy equation. In thecases of transparent and participating media with differentoptical thicknesses, the local and mean heat flux as a functionof the Rayleigh number was studied. The heat flux was alsoanalyzed for different values of the Rayleigh number in orderto investigate the effect of the Planck number. The resultsobtained in the mid-plane of a long rectangular enclosurewere compared to a purely two-dimensional case. It has beenshown that the radiation significantly increases the heat fluxin a transparent medium and that for a given Planck numberand constant reference temperature ratio, the contribution ofradiation remains almost constant for a variety range ofRayleigh numbers.

کلیدواژه ها:

Radiation ، Threedimensional ، Discreteordinates method ، Naturalconvection ، Participatingmedia