Lid-driven flow and heat transfer in a closed cavity via COMSOL

Abstract

This thesis focuses on two fundamental aspects of fluid dynamics and heat transport inside enclosed spaces. Using computer simulations via Comsol with the Finite Element Method (FEM), the research analyzes how fluids behave in these spaces. In the first sce nario, we concentrate on a square cavity with a moving slit positioned at three different places. By using mathematical concepts of mass, momentum, and energy conservation, we study how velocity patterns, temperature distributions, and isothermal limits vary with changing Reynolds and Richardson numbers. Our simulations not only support theoretical expectations but also indicate the creation of a whirling vortex, regions of recirculation, and alterations in heat dispersion driven by both the slit’s positioning and the cavity’s shape. This study increases our knowledge of the underlying rules that regu late fluid dynamics and thermal behaviour in constrained spaces, delivering vital insights for a broad variety of engineering and environmental applications. The second research focuses on nanofluid convection in a trapezoidal permeable cavity under inclined mag netohydrodynamics (MHD), emphasizing heat production by split lids and the presence of a circular obstruction. Mathematical models, incorporating nonlinear partial differ ential equations and specific correlations for nanofluid properties, explore the impact of various parameters such as Reynolds number, heat generation rate, nanoparticle volume fraction, and magnetohydrodynamic inclination angle on velocity profiles, temperature distribution, and isotherm formations. The study demonstrates considerable implications of these factors on heat transfer rates and flow patterns, notably emphasizing the effects of nanoparticle concentrations, incline MHD and cavity shape.