ETD system

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Tesi etd-03102007-102407

Thesis type
Tesi di laurea vecchio ordinamento
Simoncini, Simone
email address
Sviluppo concettuale di un endoreattore bipropellente autopressurizzato a perossido di idrogeno ed etano
Corso di studi
Relatore Prof. d'Agostino, Luca
Relatore Prof. Andrenucci, Mariano
Relatore Ing. Pasini, Angelo
Relatore Ing. Torre, Lucio
Parole chiave
  • perossido di idrogeno
  • FVP
  • endoreattore
  • etano
Data inizio appello
Riassunto analitico
In recent years space missions become more ambitious so the need for<br>reducing the costs and increasing the capabilities of rocket systems<br>through the enhancement of their propulsion performance, safety and<br>reliability represents a major aspect in the development of competitive<br>space engines. A variety of factors have resulted in an increasing<br>interest in the exploration of alternatives to widely employed cryogenic<br>and hypergolic propellant combinations. These factors include heightened<br>sensitivity to cost, environmental concerns and personnel protection<br>from the hazards associated with the use of present highly toxic<br>propellants. The current standard in high-performing, storable<br>bipropellants is the combination of nitrogen tetroxide (NTO) and<br>hydrazines (N2H4, MMH and UDMH); these propellants are extremely toxic,<br>carcinogenic and explosive so they presents disproportionately high<br>costs especially for small and medium size satellites. In this range of<br>satellites, hydrogen peroxide (HP, H2O2) is widely recognized to be one<br>of the most promising non-toxic (“green”) storable propellants due to<br>its lower total costs. Hydrogen peroxide used as monopropellant has a<br>specific impulse of the order of 180 seconds but used as oxidizer in a<br>bipropellant engine it has a specific impulse of the same order of a<br>NTO- N2H4 system.<br>At the moment Alta S.p.A. is working on the development and testing of<br>advanced catalytic beds for H2O2 decomposition and their application to<br>monopropellant rocket thrusters. The expertise acquired in this sector<br>gave the possibility to analyze and assess the propulsive and<br>operational performance of innovative green bipropellant thrusters with<br>Fuel Vapour Pressurization (FVP) of hydrogen peroxide and ethane (C2H6),<br>where the catalytic reactor provides the oxidizing stream for C2H6<br>combustion. Fuel vapour pressurization systems consists in the use of<br>just one tank for both propellants and it exploit the high vapour<br>pressure of ethane to transfer both the fuel and the oxidizer into the<br>combustion chamber. This pressurization system provides a significant<br>reduction of the costs and of the overall system mass. <br>The present thesis is concerned with the conceptual analysis of the FVP<br>system, in particular with the analysis of the tank temperature and<br>pressure drift, and the preliminary measuring of a 50 N thruster<br>prototype.<br>Chapter 1 is an introduction about the performances of hydrogen peroxide<br>bipropellants rockets while in the chapter 2 are showed the physical and<br>chemical properties of hydrogen peroxide and ethane. <br>In chapter 3 is illustrated the analysis of the pressure drift of the<br>tank whit the hypothesis that the oxidizer-fuel ratio remain constant<br>during the mass extraction from the tank.<br>Chapter 4 shows the same analysis of chapter 3 but without the<br>hypothesis about the constancy of the oxidizer-fuel ratio; it also<br>illustrates the differences in the performance with the choice of the<br>mass regulation system.<br>Chapter 5 e 6 illustrate the design of the bipropellant rocket and the<br>performance’s analysis.<br>The first appendix describes the method used for evaluate the viscosity<br>and the thermal conductivity of the mixture of gas in the combustion<br>chamber, useful to calculate boundary layer and thermal parameters.<br>The thesis work is a part of an Alta’s wider project end it has been<br>carried out under the supervision of Prof. Luca d’Agostino, eng. Angelo<br>Pasini and eng. Lucio Torre