Entropy Generation Minimization Vs Thermal Mixing Due to Natural Convection in Differentially and Discretely Heated Square Cavities

Entropy generation and thermal mixing due to heat transfer and fluid friction irreversibilities during laminar natural convection in differentially and discretely heated square cavities filled with various materials (molten metals, air, aqueous solutions, oils) has been studied numerically over a range of Ra=10^3-10^5. Entropy generation terms involving thermal and velocity gradients are evaluated accurately based on elemental basis set via Galerkin finite element method for the first time in this work. Based on entropy generation minimization approach, it has been shown that the distributed heating methodology with multiple heat sources may be the efficient strategy for attaining adequate thermal mixing and uniform temperature distribution.