Three‐dimensional simulation of natural convection in cavities with side opening

Naturally buoyant flow and heat transfer in a cubic cavity with side opening is analyzed numerically. Vertical wall of the cavity is at a higher temperature than the ambient, while other walls are assumed to be adiabatic. Numerically accurate results are presented for Rayleigh numbers of 10³ to 10⁶ for a fluid having a Prandtl number of 0.71. Unstable flow is predicted for Ra = 1 × 10⁷. The aim of the work is twofold; studying three‐ dimensional flow and heat transfer in a cavity and comparing three‐dimensional results with two‐dimensional approximation to verify the validity of the two‐dimensional model. Convection fluxes are calculated using QUICK scheme with ULTRA‐SHARP flux limiter for two and three‐dimensional simulation. The results indicate that as Rayleigh number increases the difference between two and three dimensional predictions increases. Also, it is found that this difference is greater for the flow field than for the rate of heat transfer.