Heat and Fluid Flow in a Channel by Using the Finite Element Approach

Abstract

This thesis focuses on mixed convection fluid flow and heat transfer in a rectangular channel equipped with inlet and outlet ports. In the first analyses, the fluid flow and heat transfer is investigated in a channel with corrugated surfaces to evaluate how corrugation affects flow patterns and enhances heat transfer. Several parameters are varied to assess their impact on flow patterns and heat transfer, including Reynolds number, Richardson number, and the wavelength and amplitude of the waves. Heat distribution and velocity patterns are examined at various vertical positions within the channel to thoroughly assess the impact of the corrugated geometry and different parameters. For this study of laminar Newtonian fluid flow, the incompressible and steady continuity, Navier-Stokes, and energy equations are employed. These equations are solved using the Galerkin weighted residual finite element method. The simulation results offer valuable insights into how corrugation geometry contributes to heat transfer enhancement and improves fluid mixing. The second study investigates the turbulent flow around a cylindrical obstacle placed within a channel to analyze the vortex shedding phenomenon, as well as its effects on flow patterns and heat transfer. Different shapes of the obstacle are chosen to analyze how the shape influences turbulence, heat transfer, and vortex shedding. The analysis is conducted for different Reynolds numbers and over various time intervals. Heat transfer and flow patterns are examined at multiple vertical positions along the channel. The turbulent flow phenomenon is investigated using the incompressible and unsteady continuity, Navier-Stokes, and energy equations. The same numerical scheme used in the first study is also employed for this analysis. The study provides interesting insights into how different obstacle geometries alter the characteristics of turbulent flow, like the structure and intensity of vortices and their interactions with the surrounding flow. This knowledge is essential for optimizing designs in applications where efficiency and performance are greatly influenced by turbulence and vortex behavior.