Molecular Dynamics Simulation of Non-ionized Dipole Gases for Electromagnetic Propulsion
Open Access
- Author:
- Contri, Jeffrey
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 12, 2019
- Committee Members:
- Dr. Michael Micci, Thesis Advisor/Co-Advisor
Dr. Amy Pritchett, Committee Member
Dr. Sven Bilen, Committee Member - Keywords:
- molecular dynamics
simulation
water
electric propulsion
electromagnetic propulsion
Abraham effect
island hopping - Abstract:
- A parallel molecular dynamics code was developed to simulate ensembles of water molecules in the presence of electric and magnetic fields to showcase the Abraham effect. Capitalizing on this phenomenon would allow the exploration of a new method of electric rocket propulsion without the requirement to ionize propellant – an outstanding impediment of the technology – by saving on power and raising thruster efficiency. Perfect cube ensembles ranging from 8 to 1000 molecules were investigated to find the smallest size that gave consistent, favorable behavior across 10 different initializations with random 3D orientations and velocities based on a Maxwell-Boltzmann distribution. It was sought that no matter the initialization, the average normalized z-velocity profile when the electric field was present remained higher than the profile when the electric field was absent, successfully demonstrating the Abraham effect. An 85 kV/m sinusoidal electric field was applied in the x-direction at a frequency of 75 GHz while a 2.5 T static magnetic field was applied in the y-direction. Over a period of 250 ps, it was found that the 512-molecule ensemble was the smallest size to produce the desired velocity profile comparisons across all initializations. Further optimizing the electric field to 15 GHz provided results with an average normalized Δv of 23.87 mm/s/pulse and an average normalized z-acceleration of approximately 3.58×10^8 m/s2. For an assumed acceleration length of 20 cm, this would provide an I_sp of approximately 1220 s, which is comparable with current electric propulsion methods. Further raising the magnetic field strength an order of magnitude would theoretically raise the acceleration by an order of magnitude, rendering an I_sp of about 3860 s, far surpassing that of current Hall thrusters and ion engines. Should this revolutionary method of propulsion be experimentally verified, power spent on ionization would be eliminated and the green propellant would allow for an “island-hopping” type of space exploration by visiting a given water-bearing celestial body, refueling, and progressing to the next.