טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentLaterza Matteo
SubjectNumerical and Experimental Investigations of the Camila
Hall Thruster Plume
DepartmentDepartment of Aerospace Engineering
Supervisor Professor Emeritus Mauricio Guelman


Abstract

The CAMILA Hall thruster was developed at the Asher Space Research Institute to answer the demand for an efficient electric propulsion option at powers of a few hundred watts. This thruster separates significantly from a conventional Hall thruster, and its internal mechanism has been studied in detail Almost no information is however available on the plume behavior of such thruster. Understanding the plasma plume properties is fundamental for spacecraft

integration, and is even more important when thrusters are to be used in clusters. Clustering has been proposed as a possible application for CAMILA, with special attention on the possible use of clusters of converging thrusters at different operating points capable of controlling the total thrust vector. Existing cluster studies have only focused on parallel thrusters, and thrust vectoring studies neglected plume interactions. The problem was tackled by developing and validating a 3D numerical model of the CAMILA plume capable of simulating a cluster. The thruster boundary conditions of the code are based on existing experimental measurements of the plume near the acceleration channel exit plane. Missing data were derived analytically. To validate and calibrate the model new experimental measurements were performed at 1m from the thruster and at different operating conditions using electrostatic probes. The resulting measurements were analyzed to derive plasma properties, which show comparable trends with the numerical simulations. To properly interpret and compare cluster simulations the concept of plume divergence was properly redefined. Two-thruster cluster configurations were tested at different converging angles to provide a desired thrust vectoring. Different performance parameters were compared, such as plume divergence, effective specific impulse, and thruster efficiency. The results show that not only plume interactions contain the increase of divergence caused by thrusters being at an angle with each other, but in some cases converging clusters outperform a single thruster, while at the same time removing the need for a thrust orienting mechanisms. Different cluster configurations are optimal for different performance parameters, and a mission-specific trade-off must be done, but the developed model provides the tools necessary. These results show great promise for cluster-based thrust-vectoring and further study on the topic is advised, while at the same time continued study of the CAMILA plume will allow a more refined analysis of the performance of this thruster.