Detalhes bibliográficos
| Ano de defesa: |
2014 |
| Autor(a) principal: |
Maycol Marcondes Vargas |
| Orientador(a): |
Fernando Fachini Filho |
| Banca de defesa: |
Marcio Teixeira de Mendonça,
Wladimyr Mattos da Costa Dourado,
Elaine Maria Cardoso,
Cesar Flaubiano da Cruz Cristaldo |
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
eng |
| Instituição de defesa: |
Instituto Nacional de Pesquisas Espaciais (INPE)
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação do INPE em Combustão e Propulsão
|
| Departamento: |
Não Informado pela instituição
|
| País: |
BR
|
| Link de acesso: |
http://urlib.net/sid.inpe.br/mtc-m21b/2014/01.23.11.02
|
Resumo: |
In this work the influence of transient processes of the gas phase on the vaporization of isolated ferrofluid droplet with spherical symmetry under the influence of an external alternating magnetic field is investigated. Dispersed magnetic nanoparticles inside the droplet act as a heat source. The nanoparticle dipole reacts to the alternating magnetic field rotating the nanoparticle. The friction between the rotating nanoparticle and the surrounding liquid produces heat (viscous dissipation). Brownian motion of the liquid molecules is responsible for the nanoparticle dipoles misalignment when the magnetic field amplitude is null. Therefore, in each cycle of the magnetic field the nanoparticle rotates, generating heating in the core of the liquid. Applying this process on droplets is possible to reduce the droplet heating time. The conditions addressed in this problem leads to the magnetic power to be much larger than the thermal power, provided by the heat flux from the gas phase. The characteristic of this problem is a thermal boundary layer established close to the droplet surface in the liquid side. The magneto relaxation source is found to be dependent on initial conditions. In addition, because of the dependency of the magneto relaxation heating on temperature, a local maximum of temperature is found inside the thermal boundary layer. In the current model it is also observed the increasing of the droplet vaporization with pressure. |
