Pulsed plasma thrusters (PPTs) are preferred
low-power systems for satellites because of their simplicity and
small dimensions. This article was carried out to discuss and
calculate the basic parameters that describe the efficiency of
the electrothermal type of PPTs, using the 1-D time-depending
ETFLOW model of the electrothermal capillary discharge with
Teflon capillary. Parameters, such as the ablated mass, thrust,
impulse, and specific impulse, were calculated. In addition, the
basic plasma parameters, such as temperature, pressure, density,
velocity, and heat flux, were all studied as a function of discharge
time. We also discussed the effect of using an approximation of
the transmission heat factor of Teflon. The influences of some
input parameters as applied voltage and capillary geometry on
thruster parameters were studied. It was found that ablated
mass increases with the applied voltage or capillary length and
decreases as the capillary diameter increases. Finally, calculations
were compared to the measured results of ablated mass, impulse,
and specific impulse from different works. The results of our
model are in good agreement with experimental results with small
variations in impulse and specific impulse values. Variations are
expected to be limited if we enter some modifications to the
model to increase the exit velocity and use the radial dimension
for calculations. |
