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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-09262003-132108


Thesis type
Tesi di laurea vecchio ordinamento
Author
Andreussi, Tommaso
email address
t.andreussi@sssup.it
URN
etd-09262003-132108
Thesis title
Hybrid-PIC Modeling of Hall Thruster Acceleration Channels
Department
INGEGNERIA
Course of study
INGEGNERIA AEROSPAZIALE
Supervisors
relatore Prof. Andrenucci, Mariano
Keywords
  • Motori ad effetto Hall
  • Propulsione Aerospaziale
Graduation session start date
21/10/2003
Availability
Withheld
Release date
21/10/2043
Summary
In order to study the physics of the acceleration process in Hall Thrusters, an innovative hybrid particle-in-cell (PIC) numerical model has been developed in this work.
A set of two dimensional axisymmetric fluid equations are used for electrons, while heavy species such as ions and neutrals are modeled via a particle tracking approach.
The two solutions are linked by charge neutrality.
The computational domain covers all the acceleration channel, boundary conditions are imposed on sheath-plasma interface based on classical plasma physics assumptions.
The code is able to perform a full simulation of the flow proceeding through neutral injection, ionization, ions acceleration and collision processes up to particles expulsion into the free space.
Electrons are expected to reach stationary state in a very shorter time if compared with typical ions and neutrals time-step; consequently, electrons equations are solved every PIC time-step giving as output the electric field and the ionization rate, both consistently evaluated with heavy species instantaneous distributions.
The aim of this work is to predict Hall Thruster performances and to provide a reliable mean for sensitivity analysis on main geometrical and system parameters.
First results on simulations performed are in great accordance with experimental and numerical results reported by several authoritative publications. In order to reduce those discrepancies, future developments of the code could include extension of the simulation domain out of the channel and plume tracking in the region close to the exhaust of the thruster.
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