Influência da potência magnética no aquecimento e vaporização de Ferrofluido combustível

Abstract

This works refers to the process of magnetic heating applied in a ferrofluid fuel. This process consists in the generation of energy by viscous dissipation caused by the movement of nanoparticles under the influence of an alternated magnetic field. This process is being studied as a method of improve the combustion, due to the increase caused in the fuel vaporization rate. The mathematical models that describe this process, until now, considerate the influence of a high power magnetic fled acting in a ferrofluid droplet. In those cases, there is the formation of a thermal boundary layer close to the droplet surface, and the solution is obtained rescaling the equations on time and space. By this way, the geometrical effect (droplet curvature) becomes negligible and the solution is obtained in rectangular coordinates. Considering that the low power magnetite field was not well explored, and that it is more viable, the objective of this study is to extend the analysis of the effects of the magnetic heating in ferrofluid droplets to the case of unitary order magnetic field. For this, the mass, energy and chemical species conservation equations must be numerically solved, in spherical coordinates. The magnetic power variation is given by a magnetic parameter, which is the set of the magnetic field proprieties. In this work, it is compared values as the temperature distribution evolution, vaporization rate, droplet radius variation and heating time (time to the droplet reach the ebullition temperature), for different magnetic parameter and frequency. It is observed that the magnetic heating still influencing strongly in the case of Pm of unitary order, noting that with the increase of Pm, the ebullition temperature is obtained in the interior of the droplet causing great diminution of the heating time and high vaporization rate.