TITLE:
Numerical Simulation of Natural Air Convection in Inclined Eccentric Hemispheres Enclosure
AUTHORS:
Mariama Néné Koita, Mamadou Lamine Sow, Oumar Dramé, Babacar Mbow, Cheikh Mbow, Joseph Sarr
KEYWORDS:
Bispherical Coordinates, Hemispherical Cavities, Rayleigh Number, Nusselt Number, Eccentricity, Streamlines, Isotherms
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.11 No.6,
June
29,
2021
ABSTRACT: The subject of natural convection heat transfer is motivated by a wide range of applications in engineering technology. The hemispherical cavity is a part of basic geometries although it is not widely studied. The effect of inclinaison on natural convection fluid motions in the gap between two eccentric hemispheres is numerically studied. The inner hemisphere is subjected to a heat flux of a constant density and the outer one is maintened isothermal. The walls separating the two hemispheres are thermally adiabatic. Equations are formulated with vorticity and stream-functions variables. It is also assumed the fluid incompressible and obeys the approximation of Boussinesq. These equations are written by using bispherical coordinates system and solved by using a finite difference method. The results show the topology of flow is strongly dependent on the inclinaison because the flow can change from a unicellular regime to a multicellular regime by varying the inclination from 0 to π. By increasing the Rayleigh number (103Ra7), the flow intensifies. The results are shown in terms of streamlines and isotherms during their transient evolution.