November 22, 2024
Gholamreza Imani

Gholamreza Imani

Academic Rank: Associate professor
Address:
Degree: Ph.D in Mechanical Engineering-Thermo-Fluids
Phone: 07131222717
Faculty: Faculty of Engineering

Research

Title
Heat transfer characteristics of a porous wrapped circular cylinder undergoing vortex-induced vibration
Type Thesis
Keywords
Porous wrapped cylinder, Heat transfer, vortex- induced vibration
Researchers Yasser Amini (Primary advisor) , Gholamreza Imani (Primary advisor)

Abstract

Heat transfer phenomenon plays an important role in most industrial issues. Therefore, methods of improving heat transfer for the optimal use of energy resources are very important. In the last two decades, the use of porous materials in heat exchangers as a passive method of improving heat transfer has been seriously discussed due to its characteristics such as increasing the surface area per unit volume. In the first part of this thesis, the fluid flow and heat transfer from a Full porous circular cylinder under forced vibration in a cross-flow are simulated using Ansys-Fluent software. The effect of Darcy number, reduced frequency, vibration amplitude and Reynolds number on the hydrodynamic and thermal characteristics of the cylinder has been studied. The results showed that for a small range of Darcy numbers, in large amount of frequency and amplitude of oscillation, that vortex shedding phenomenon may occur which causes an increase the heat transfer rate. While in Darcy numbers there is no vortex shedding phenomenon and instead combining the high penetration of flow with flow fluctuations improves the heat transfer rate. One of the types of porous heat exchangers is the shell-tube heat exchangers, which uses a porous coating on the outer surface of the tubes. In shell-tube heat exchangers, the vortex shedding phenomena occurs at certain Reynolds number, shedding vortices exert periodic forces on the tube that causes it to oscillate, so-called vortex induced vibration. In order to more accurately predict the pressure drop and heat transfer coefficient obtained from the numerical simulation of heat exchangers, this vibrational motion of the tubes must be taken into account. In the second part of the thesis, fluid flow and heat transfer from a cylinder with a porous coating under vortex-induced vibrations are investigated. The vibrational motion of the cylinder is modeled by a mass spring damping system using ANSYS-FUENT software. The effect of parameters such as