On the aspect ratio for which the heat transfer in differentially heated cavities is maximum

Abstract A numerical study of two dimensional natural convection of air in rectangular, differentially heated cavities was conducted. For three Rayleigh numbers the aspect ratio S was varied. It was found that heat transfer between the active walls has a maximum at each Rayleigh number, which is located at values of S between 1 and 2. The aspect ratio for which the maximum heat transfer occurs is determined by the process of transition from a shallow cavity regime to a slender cavity regime.