Abstract
Numerical analysis of natural convection flows in a 8:1 differentially heated square cavity have been carried out. Objectives of this study is to investigate the flows precisely with the Rayleigh number equals to 3.5×105 and to find out the critical Rayleigh number at which the steady flow changes to the flow with oscillation by means of parameter study for Rayleigh numbers. The GSMAC finite element method was applied to calculate the flow field and the CIP finite element method was used to solve the advection phase of the energy equation. Various time history data were obtained and periods and amplitudes of the data are calculated using FFT. Obtained data are good agreement with other calculated data. Parameter study for Rayleigh numbers was carried out and relationship between amplitude of velocity and temperature and Rayleigh numbers were calculated. The critical Rayleigh number with this scheme is approximated 2.9×105.
