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.
