Balamir Sahin
Interview with Jacques Richard, Associate Professor at Texas A&M University
Updated: Sep 4, 2021

Interview:
Could you tell us about who you are?
I am a person who likes developing an understanding of how the physics of many things around us work to better develop engineering mechanisms to improve or generate solutions/devices for all. That also includes my interest in engineering education research: getting a better understanding of how engineering education is making engineers out of engineering students. My research has uncovered how plasmas are controlled by electromagnetic fields for propulsion and flow control. My research has uncovered how effective communication, teamwork, networking, etc., can enable enhanced effective learning.
Why did you want to become an aerospace engineer?
I liked flying vehicles & wanted to be part of their design & not just use them to go many places, etc.
How does an ion thruster work?
An electric field is set up between 2 porous grids of opposite charges or different voltages. The field accelerates ions (plasma exhaust stream) through the porous grids w/ high enough speeds such that it imparts a momentum to the vehicle on which the thruster is mounted in the direction opposite to the exhaust stream. An electron beam near the exit of the thruster, on the outside, is sent to the ion/plasma exhaust stream to neutralize the ions so that they are not attracted back to the thruster which would result no net thrust.
What are some of the advantages and disadvantages of an ion thruster?
Extremely high exhaust velocities (10’s of km/s, 10 times space shuttle main engines (SSME) exhaust gas speed) means that the propellant is not used up as fast. The thrust is low for a plasma density lower than SSME (similar to even SpaceX rockets) but the propellant is not used up as fast. Chemical rockets like SSME or the like use up propellant w/in minutes whereas ion thrusters can run for 10,000+ hours. That long run time in space (far from planetary atmospheric drag) means that they can attain enough speed to go farther than many chemical propulsion systems could.
Can you explain your study about plasma jets in magnetic fields?
I apply conservation of linear momentum principles (Newton’s Laws) to charged particles in an electromagnetic field generated by a current-eating wire coil surrounding the plasma stream to accelerate it to the aforementioned high velocities. This is in lieu of electric grids in ion thrusters but still called electric propulsion (EP) as I guess it is electromagnetic in nature & uses a lot of electricity.
What is the goal in studying the interaction between atmospheric and ocean waves?
The waves can transmit through different media (water, ground, etc.) & enable seismic detectors to register their presence. This can help provide info about what could cause the waves & how to prepare for destructive waves (earthquakes, tsunamis, bomb lasts, etc.).
What are the Lattice-Boltzmann methods?
Model media (fluid, plasma) as microscopic or sub-microscopic (e.g., meso-scopic) lattices (Cartesian grid cells) on which to solve a linearized form of Boltzmann’s equations for the statistical distribution of particles & their velocities in each lattice & enable computing the effects of the average momentum & energy of particles (e.g., thrust)
What are Spectral element methods?
Discretizing or decomposing a domain being modeled on the computer (e.g., chunks of an engine) into microscopic discrete elements (or lattices or cells) & applying a linear combination or sums of different types of spectral functions (e.g., Fourier spectral would be sines & cosines) to approximate the variations in key properties. E.g., velocity as such a combination & then numerically solve for the coefficients in the sums of combinations of spectral functions that give the best describe the physical system response subject to the conservation principles and system geometry.
What has been your toughest accomplishment so far in your career?
I am still researching a lot that I want to understand & happy to be able to contribute to the general body of knowledge but I wish I had more time & other resources to get more done.
To highschoolers like me and to younger generations that want to become aerospace engineers, what would be your advice to be successful in this career?
Most of your work will be in written form so practice a lot of writing. The science, math, engineering, tech has to be done right but also has to be clearly explained to make meaningful contribution to the body of knowledge & to be sure that many people properly understand them.