About Prof. Raja

Dr. Raja is a Professor in the Department of Aerospace Engineering and Engineering Mechanics at The University of Texas at Austin.  He holds a Ph.D in Mechanical Engineering from The University of Texas at Austin, M.S. in Nuclear Engineering from Texas A&M University, and a B. Tech in Aerospace Engineering from the Indian Institute of Technology, Chennai (Madras) India.

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Computation Modeling and Simulations of Micro-Cavity Discharge (MCD) Thrusters

Computational modeling and simulation studies of novel Micro-Cavity Discharge (MCD) Thruster devices for small satellite propulsion are being performed.  MCD thrusters are a class of electrothermal propulsion devices for small satellites.  MCD thrusters are driven by low radio-frequency micron-scale dielectric barrier discharges in a flow-through (plasmatron) configuration.  Through computational modeling and simulations we have shown that highly controllable gas heating is possible in such devices and is the basis for the electrothermal thruster.  

Simulation of Radio-Frequency Capacitively Coupled Plasma Discharges for Atomic Layer Deposition

We are performing simulation studies of radio-frequency capacitivelty coupled plasma discharges used in the fabrication of thin films by atomic layer deposition.  Simulation results are being validated by experimental results by our collaborators Prof. Wolden at the Colorado School of Mines (http://inside.mines.edu/fs_home/cwolden/wolden2.htm).  The goal of this collaborative project is to develop a fundamental understanding of the process through a combination of extensive diagnostics and state of the art computational modeling.

Computational Studies of Aspetity-Scale Plasma in Rail-Armature Contact Gaps in Electromagnetic Launchers

A computational simulation study of direct-current plasma discharge phenomena in small length-scale geometries (<10 µm) is described.  The primary goal is to study discharge breakdown characteristics in small length scale geometries as quantified by a modified Paschen breakdown curve and the quench characteristics in these discharges.  A self-consistent non-equilibrium plasma model is used for the simulation studies.  The model includes field emission effects which is a key process in determining small length-scale breakdown behavior.  The breakdown curves obtained from the experiment and simulation showed excellent agreement providing a measure of validation for the model.  Quantification of the heat fluxes from the simulations show higher erosion at cathode, and a highly nonlinear heating behavior with applied over-voltages above the breakdown threshold.

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