A ferrofluid is an electrically nonconductive colloidal suspension consisting of a carrier liquid and magnetic nanoparticles. The novelty of ferrofluids is that the fluid flow and properties may be controlled by an external magnetic field and thermal field. Since the discovery of the unique properties of ferrofluids, several applications for ferrofluids have been considered; the variety of applications is diverse, ranging from biomedical and technical to scientific applications.;In this thesis, the thermomagnetic convection effect of a ferrofluid in a differentially heated flow loop under the influence of an external magnetic field has been investigated analytically, numerically and experimentally. The physics of thermomagnetic convection is a highly multi-disciplinary area, which combines fluid dynamics and heat transfer with magnetism. This application utilizes ferrofluids whose magnetic properties are strongly influenced by temperature which are called temperature sensitive ferrofluids (TSFF) in this study. When a temperature sensitive ferrofluid experiences a temperature variation in the presence of an external magnetic field, the balance of the induced magnetic body force is broken and a thermomagnetic driving force is produced.;The objective of this research is to characterize the thermomagnetic circulation through a flow loop in terms of geometric length scales, ferrofluid properties, and the strength of the imposed magnetic field with the goal to provide a practical design approach for liquid cooling of electronics using of thermomagnetic effect of ferrofluids with no mechanical pump.;In the analytical study, a one-dimensional model has been developed using scaling arguments to characterize thermomagnetic circulation in a flow loop in terms of physical parameters. Accordingly, a correlation for the non-dimensional heat transfer (Nusselt number) as a function of the appropriate magnetic Rayleigh number and a correlation for the mass flow rate based on the system properties (magnetic Grashof number) were developed.;In parallel to the analytical analysis, thermomagnetic circulation flow loops were investigated numerically. The experimentally validated three-dimensional, incompressible, laminar numerical simulation models included the heat transfer process from a temperature sensitive ferrofluid contained in a closed flow loop under the influence of an external magnetic field. These models were established using COMSOL Multiphysics simulation software which in addition to solving the standard conservation equations, also solve for the magnetic field inside the simulation domain using the Maxwell equations, and include the necessary terms to take into account the magnetic body force to add to the momentum equation. Results of these numerical investigations have been used to develop semi-empirical analytical correlations. Additionally, the effect of relative positions of the heat source and the magnetic field source on system performance has been studied by considering six different cases.;The experimental measurements using a single-phase, temperature sensitive ferrofluid (TMA-250) operating under transient and steady-state laminar flow conditions in a partially heated thermomagnetic circulation flow loop under the influence of the magnetic field were used to validate the analytical and numerical studies. The cooling performance of the device with different magnetic field strengths and heating rates on the heating section were investigated. The results have revealed that flow in these devices can be controlled by the magnetic field and temperature distribution, and that the device possesses a self-regulating function corresponding to the heat source heat rate. This feature may be used as a self-regulating cooling device for thermal management of electronics without the need for a mechanical pump or sensors and an external control system.
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