@PhDThesis{Hennemann:2015:EsTePr,
author = "Hennemann, Luciano",
title = "Estudo te{\'o}rico-experimental de um propulsor monopropelente a
{\'o}xido nitroso usando catalisador de r{\'o}dio suportado",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2015",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2015-02-20",
keywords = "catal{\'{\i}}tico, {\'o}xido de r{\'o}dio, catalisador,
catalytic, rhodium oxide, catalyst.",
abstract = "O {\'o}xido nitroso {\'e} um monopropelente com uso potencial em
sistemas de propuls{\~a}o de sat{\'e}lites. Este trabalho
apresenta uma investiga{\c{c}}{\~a}o te{\'o}rico-experimental
de um propulsor com empuxo de 2 N empregando {\'o}xido nitroso
gasoso como monopropelente, decomposto por um catalisador
suportado e com pr{\'e}-aquecimento do propelente e do
catalisador por um sistema \emph{glow-plug}. Inicialmente foi
realizado um estudo te{\'o}rico dos par{\^a}metros propulsivos e
o dimensionamento do propulsor para opera{\c{c}}{\~a}o em
condi{\c{c}}{\~a}o ambiente. Adotou-se um projeto modular
permitindo o uso de leitos catal{\'{\i}}ticos de diferentes
comprimentos e di{\^a}metros. Devido {\`a} sua efici{\^e}ncia
de decomposi{\c{c}}{\~a}o, um catalisador com {\'o}xido de
r{\'o}dio suportado em alumina foi preparado nos
laborat{\'o}rios do INPE/LCP e usado para
decomposi{\c{c}}{\~a}o do {\'o}xido nitroso. Os gr{\~a}os de
catalisador eram extrudados cil{\'{\i}}ndricos com cerca de 2 mm
de di{\^a}metro e 3 mm de comprimento. Foi realizada a
constru{\c{c}}{\~a}o de prot{\'o}tipos com diferentes
c{\^a}maras e foram executados testes de desempenho do propulsor.
Uma bancada experimental existente foi adaptada para a
realiza{\c{c}}{\~a}o dos testes e avalia{\c{c}}{\~a}o dos
propulsores. Foram medidos o empuxo, vaz{\~a}o m{\'a}ssica de
oxidante, al{\'e}m das press{\~o}es e temperaturas na linha de
alimenta{\c{c}}{\~a}o e na c{\^a}mara do propulsor. A partir
dos dados experimentais foram determinados os par{\^a}metros
propulsivos como impulsos espec{\'{\i}}ficos, coeficientes de
empuxo, velocidades caracter{\'{\i}}sticas e efici{\^e}ncias.
Dois modelos computacionais foram desenvolvidos para descrever o
funcionamento do propulsor. Um modelo unidimensional em regime
permanente utilizando a Equa{\c{c}}{\~a}o de Ergun para meios
porosos, com taxas de rea{\c{c}}{\~a}o homog{\^e}nea e
heterog{\^e}nea, foi utilizado para simular a
decomposi{\c{c}}{\~a}o do propelente e determinar a
distribui{\c{c}}{\~a}o de temperaturas e a
composi{\c{c}}{\~a}o final ao longo do leito
catal{\'{\i}}tico. Um modelo t{\'e}rmico de par{\^a}metros
concentrados, tamb{\'e}m considerando taxas de rea{\c{c}}{\~a}o
homog{\^e}nea e heterog{\^e}nea, avaliou o comportamento
transiente do escoamento e da distribui{\c{c}}{\~a}o de
temperaturas no propulsor, permitindo simular o funcionamento
pulsado do propulsor. As curvas de temperatura e demais dados dos
modelos te{\'o}ricos foram comparadas {\`a}s curvas
experimentais, obtendo-se razo{\'a}vel concord{\^a}ncia.
ABSTRACT: Nitrous oxide is a monopropellant with potential for use
in propulsion systems of satellites. This work presents a
theoretical and experimental investigation of a 2N thruster
prototype using gaseous nitrous oxide such as the monopropellant.
The nitrous oxide is decomposed by a supported catalyst with
pre-heating of the gaseous propellant and the catalyst by a glow
plug. Initially a theoretical study of the propulsive parameters
and the design of the engine for operation in ambient condition
were performed. A modular design was adopted allowing the use of
catalytic beds with different lengths and diameters. Due to its
high decomposition efficiency, a rhodium oxide catalyst supported
in alumina was prepared at LCP/INPE laboratories and used for
nitrous oxide decomposition. Catalyst pellets had about 2 mm
diameter and 3 mm length. Prototype thrusters with different
chambers were manufactured and performance tests were made. An
existing test bench was improved for testing and evaluation of the
thrusters. The measured parameters included thrust level, mass
flow of oxidizer, pressures and temperatures in the supply line
and in the propellant chamber. From the experimental data the
propulsive parameters such as specific impulse, thrust
coefficients, characteristic speeds and efficiencies were
determined. Two computational models were developed in order to
reproduce the thruster behavior. A steady one-dimensional model
using the Ergun equation for porous media flow, with homogeneous
and heterogeneous reaction rates, was used to simulate the
decomposition and to predict the final temperature and composition
along the catalytic chamber. A lumped parameter thermal model,
also considering homogeneous and heterogeneous reaction rates,
described the transient behavior of the flow and temperature
distribution during pulsed operation of the thruster. The
theoretical curves of temperature and other properties from both
models were compared with the curves obtained experimentally
indicating reasonable agreement.",
committee = "Costa, Fernando de Souza (presidente/orientador) and Savonov,
Roman Ivanovitch and Soares Neto, Tur{\'{\i}}bio Gomes and
Marchi, Carlos Henrique and Veras, Carlos Alberto Gurgel",
copyholder = "SID/SCD",
englishtitle = "Theoretical and experimental study of a monopropellant thruster
with nitrous oxide using rhodium catalyst supported",
language = "pt",
pages = "177",
ibi = "8JMKD3MGP3W34P/3HQFEQ5",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3HQFEQ5",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}