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Advisor(s)
Abstract(s)
O electrospray é um fenómeno que apresenta um enorme potencial em várias aplicações,
como a propulsão aeroespacial, onde é ideal para a correção da órbita de pequenos
satélites. Outras aplicações incluem a espectrometria de massa e a deposição de
partículas, sendo esta a aplicação mais versátil. No entanto esta é uma tecnologia que vê
muito pouco uso atualmente devido, em grande parte, ao facto de ser pouco conhecida e
relativamente pouco estudada. No entanto, já se começam a observar os benefícios da
implementação deste fenómeno em aplicações como a pintura e a entrega de
micropartículas orgânicas em medicina. Uma das partes essenciais do electrospray, e que
tem recebido menor atenção ao longo dos anos, é a parte relativa ao spray de partículas.
Isto leva a que a parte que realmente se aproveita nas aplicações (a do spray de
partículas) se mantenha menos conhecida e aprofundada.
Com este trabalho, pretende-se construir uma instalação no laboratório ClusterDEM da
Universidade da Beira Interior, de forma a produzir e analisar electrosprays com
diferentes condições eletro-hidrodinâmicas. Esta instalação foi projetada tendo em conta
os valores típicos de caudal e tensão aplicada. Tentou-se utilizar um sistema PIV para a
obtenção do campo de velocidades do spray. No entanto, as imagens obtidas para tal
apresentaram enormes quantidades de ruído, não sendo possível realizar a devida
análise. Foram ainda analisados aspetos como a tensão mínima para o estabelecimento
do modo cone-jet, e foram obtidas imagens que permitiram obter uma melhor
compreensão das transições entre modos.
Electrospray presents immense potential in various applications, such as aerospace propulsion, where it is ideal for the correction of small satellites’ orbits. Other applications include mass spectrometry and particle deposition, being this last one the most versatile. However, this is a technology that currently sees little use, majorly due to not being widespread enough and relatively unexplored. Nonetheless, the benefits of electrospray implementation are already starting to be noticed in applications such as painting and organic microparticle delivery. One essential part of the electrospray, that has gotten less attention throughout the years, is the one relative to the particle spray. This leads to the ultimately useful part (the particle spray) not being as well studied. This work intends to create an experimental facility for the ClusterDEM lab in University of Beira Interior, with the aim of producing and analyzing electrosprays with different electrohydrodynamic conditions. This facility was designed with the typical value of flow rate and voltage in mind. An effort was made to use a PIV system, in order to obtain the velocity field in the spray zone. Howerever, the images show large amounts of noise, that make such analysis impossible. A few other aspects of the electrospray were analyzed such as the minimum voltage required for the cone-jet mode. Images of the transition between different modes are also presented, which allow a better comprehension of such transitions.
Electrospray presents immense potential in various applications, such as aerospace propulsion, where it is ideal for the correction of small satellites’ orbits. Other applications include mass spectrometry and particle deposition, being this last one the most versatile. However, this is a technology that currently sees little use, majorly due to not being widespread enough and relatively unexplored. Nonetheless, the benefits of electrospray implementation are already starting to be noticed in applications such as painting and organic microparticle delivery. One essential part of the electrospray, that has gotten less attention throughout the years, is the one relative to the particle spray. This leads to the ultimately useful part (the particle spray) not being as well studied. This work intends to create an experimental facility for the ClusterDEM lab in University of Beira Interior, with the aim of producing and analyzing electrosprays with different electrohydrodynamic conditions. This facility was designed with the typical value of flow rate and voltage in mind. An effort was made to use a PIV system, in order to obtain the velocity field in the spray zone. Howerever, the images show large amounts of noise, that make such analysis impossible. A few other aspects of the electrospray were analyzed such as the minimum voltage required for the cone-jet mode. Images of the transition between different modes are also presented, which allow a better comprehension of such transitions.
Description
Keywords
Cone-Jet Electrospray Experimental Modelos Analíticos Spray de Partículas Técnica Piv