ICE-WATER CONVECTION IN AN INCLINED RECTANGULAR CAVITY FILLED WITH A POROUS-MEDIUM

This paper reports on the results of a numerical study on the equilibr ium state of the convection of water in the presence of ice in an incl ined rectangular cavity filled with a porous medium. One side of the c avity is maintained at a temperature higher than the fusion temperatur e while the opposite side is cooled to a temperature lower than the fu sion temperature. The two remaining sides are insulated. Results are a nalysed in terms of the density inversion parameter, the tilt angle, a nd the cooling temperature. It appears that the phenomenon of density inversion plays an important role in the equilibrium of an ice-water s ystem when the heating temperature is below 20 degrees. In a vertical cavity, the density inversion causes the formation of two counterrotat ing vortices leading to a water volume which is wider at the bottom th an at the top. When the cavity is inclined, there exist two branches o f solutions which exhibit the bottom heating and the side heating char acteristics, respectively (the Benard and side heating branches). Due to the inversion of density, the solution on the Benard branch may fai l to converge to a steady state at small tilt angles and exhibits an o scillating behavior. On the side heating branch, a maximum heat transf er rate is obtained at a tilt angle of about 70 degrees but the water volume was found to depend very weakly on the inclination of the cavit y. Under the effect of subcooling, the interplay between conduction in the solid phase and convection in the liquid leads to an equilibrium ice-water interface which is most distorted at some intermediate cooli ng temperature.