Evaluation of PTFE-fed PPT performance by means of an unsteady electromechanical model

GOMEZ, EMMANUEL; SARAVIA, MANUEL; CASTELLO, WALTER; ELASKAR, SERGIO

Conferencia; 8th INTERNATIONAL CONFERENCE ON SPACE PROPULSION ? SP2022; 2022

In the last three decades, the need of reducing costsand program schedules, led to a larger emphasison the development of lighter and smaller satellites.Moreover, the surge of large constellations of satellites weighting between 10 and 50 kg, increased thedemand for the satellites to have manoeuvring capabilities. It is in this aspect where the ablative PulsedPlasma Thrusters present themselves as a valuablealternative, thanks to their simple construction, theirhigh specific impulse, and a small impulse bit, together with a reduced weight, the absence of complex propellant management systems and low powerrequirements.This work proposes an unsteady electromechanical model to simulate PPT discharges, aimed atcharacterizing the thruster performance. The numerical implementation allows to estimate performance parameters, such as the ablated mass, theimpulse bit, the specific impulse and the propulsiveefficiency, among others. The proposed model differs from previous models found in the literature byincorporating the energy equation, which allows tosolve for the electron temperature as an additionaltime-dependant variable for the model. The electrondensity evolution is obtained using the Saha equation, by assuming a Local Thermodynamic Equlibrium.The model has been compared and validated withexperimental results from the literature. A sensitivity analysis with respect to geometric and electricalparameters is pursued to assess their impact on theablated mass, the impulse bit, the specific impulseand the propulsive efficiency.