Irreversibilities in natural convection inside a right-angled trapezoidal cavity with sinusoidal wall temperature

Analysis on natural convective heat transfer in different engineering systems allows optimization of the technical apparatus. For this purpose, numerical simulation of the fluid flow and heat transport within the system is combined with study of entropy generation. The latter is very important considering the Gouy–Stodola theorem of thermodynamics. The present research deals with the mathematical modeling of thermal convection and entropy generation in a right-angled trapezoidal cavity under the influence of sinusoidal vertical wall temperature distribution. Control Oberbeck–Galerkin finite element technique has solved Boussinesq equations formulated using the non-dimensional primitive variables. Analyses of flow structures, thermal and entropy generation patterns for different values of the Rayleigh number, and parameters of non-uniform wall temperature were performed. It was found that a rise in the sinusoidal wall temperature amplitude increases the average Nusselt and Bejan numbers and average entropy generation. Moreover, growth in the non-uniform wall temperature wave number decreases the energy transport strength and Bejan number.