Numerical Investigation of Natural Convection in a Vertical Annulus Enclosure


A numerical technique is developed to predict both the transient and steady axisymmetric two-dimensional natural convection heat transfer for water as the working fluid in a vertical annulus enclosure of a fixed radius ratio (2) aspect ratio (1) and Rayleigh number ranging within (103 ≤Rad≤106) for a fixed Prandtl number (Pr=7). Finite difference analogs of the Navier – Stokes and thermal energy equations are solved in the stream function – vorticity frame work. The results obtained are presented graphically in the form of streamline, vorticity and isotherm contour plots. A correlation has been set up to give the average Nusselt number variation with Rad and for which the results are found to be in good agreement with previously published experimental data.