Effect of aspect ratio on the onset of natural convection in porous trapezoidal enclosures

Abstract

Understanding the impact of aspect ratio is the objective of this numerical inquiry and various temperature boundary conditions on fluid flow and buoyant heat transfer in a porous trapezoidal cavity. The upper wall is cool, the steep walls are adiabatic, and the base wall is subjected to uniform, linear, and non-uniformly varying temperatures. The study makes use of the Darcy model. Using a simple algorithm, the governing equations are resolved via the finite element technique. Numerous parameters are considered in the computations, and the results are displayed graphically. The results show that the various heating and aspect ratios (AR = H/L = 0.25, 05, 0.75, and 1) significantly affect the flow pattern within the enclosure. For increasing levels of the Rayleigh number, the rate of heat transfer increases with constant aspect ratio. As the aspect ratio rises, the rate of heat transfer decreases. The outcomes are presented as the local and mean Nusselt numbers, the stream's functions, and the isotherm functions. In addition, the obtained results compared with previous researchers and show good agreement. Present numerical solutions are more useful for mixed mode porous matrix in solar panels.