AE Brown Bag Seminar
Joshua Lee
Hridai Ambati
Josh Erales
Athira Nair
Friday, October 24
11:00 a.m. - 12:20 p.m.
Guggenheim 442
Pizza Served
Hridai Ambati
Title:
A Multi-Agent Spacecraft Simulation Framework for Formation Flight.
Abstract:
The transition from large, monolithic satellites to fleets of smaller spacecraft demonstrates the critical role of validating and evaluating distributed space systems for the future of scientific and commercial missions. This paper presents a high-fidelity simulation framework for the study of formation flight dynamics, development of GNC (guidance, navigation, and control) algorithms, and the simulation of inter-spacecraft interactions. The framework is built on Robot Operating System 2 (ROS 2) and the physics engine MuJoCo. The simulation environment takes place in a relative orbit scenario where dynamics models such as the Hill–Clohessy–Wiltshire (HCW) equations can be selected to determine the behavior of all bodies. The simulation supports multiple spacecraft agents with independent sensors, actuators, robotic arms, and GNC systems. State estimation on each spacecraft involves filtering, using a chosen method such as the Extended Kalman Filter (EKF), for sensors such as accelerometers, gyroscopes, and cameras. The GNC systems feature cooperative control algorithms for orbit maneuvers and robotic-arm interactions. Preliminary results demonstrate accurate tracking of desired relative trajectories under disturbances, efficient actuator usage, and scalability to larger formations. The architecture is designed to be extensible and provides a tool to integrate more advanced techniques such as reinforcement learning (RL). By combining multi-agent dynamics, estimation, and control, the framework provides a powerful and adaptive tool for improving performance in real-time spacecraft formation flight.
Faculty Advisor:
Prof. Yashwanth Kumar Nakka
Josh Erales
Title:
On the Development of a Large-Volume Airfoil Performance Database
Abstract:
This brown bag will focus on a broad summary of research performed by Joshua Erales under the direction of Dr. Christian Perron at the Georgia Tech Aerospace Systems Design Laboratory (ASDL). The second half of this presentation will focus on research performed during the 2025 spring semester. This research concerned the development of a large-scale database to gather aerodynamic data of over 1,600 airfoils in a data management system called HDF5 for future use by ASDL’s advanced configurations division. This database, once complete, will provide readily available data on all pertinent characteristics of any publicly known airfoil at any conditions. All aerodynamic data was informed by computational fluid dynamics simulations in an open-source CFD code called SU2. While the database was not completed during the duration of the spring 2025 semester, the researcher developed tools to parameterize all desired airfoils, developed the HDF5 database, and began CFD runs using SU2.
Faculty Advisor:
Prof. Christian Perron
Joshua Lee
Title:
NO/NH Laser Diagnostics Measurements in Henkin Burner Ammonia-Oxygen/Argon Diffusion Flames
Abstract:
Ammonia is an alternative fuel source that is carbon-free and is a potential alternative for sustainable propulsion. However, it being less reactive and the NOx byproducts currently limit its practical application. This research utilized Laser Induced Florescence (LIF) on a Henkin Burner at different orientations to be able to find a relationship between signal intensity and the NO and NH species concentration. Running these tests and using computational modeling allowed us to further understand ammonia flame kinetics as well as develop ways for a low-NOx combustion technology.
Faculty Advisor:
Prof. Wenting Sun
Athira Nair
Title:
Emissions and Flame Characterization Study on Combustion of Conventional and Alternative Fuels
Abstract:
In response to the urgency for sustainability in aviation, there has been a focus in reducing emissions from gas turbine engines found in most jet engines. Current gas turbines utilize fossils fuels such as kerosene that emit large amounts of CO2 and NOx, so particular attention has been placed on considering alternative fuels produced from biomass such as renewable diesel, bio-ethanol, and bio-methanol. Correlations have been found between reduced NOx, CO2, and particulate emissions when using these sustainable fuels. However, there are few studies with direct comparisons between biofuels. This experiment characterizes the differences between traditional fossil fuels, synthetic fuels, and alcohol fuels. It is critical to note that the experimental set-up keeps various factors of the combustion constant including critical hardware, the flame temperature, and firing pressure to directly compare between the fuels whereas previous studies typically keep the equivalence ratio constant. The set-up included a fuel cart that contained seven separate fuels: ethanol, methanol, R99 renewable diesel, sustainable aviation fuel (SAF), Jet A and diesel. These were then flowed into a pressure-swirl atomizer where a hydrogen spark torch ignited the flame in the primary zone. The specific properties that were analyzed include the emissions concentrations of NOx and CO from a water probe that that fed emissions in a gas analyzer as well as particulate matter from filter paper. OH* chemiluminescence images and Mie scattering images were also taken using an optical set-up to characterize the droplet and flame shape to potentially explain the results. The results showed renewable diesel and SAFs had similar emissions when compared to diesel and Jet A. Ethanol and methanol had increased amounts of CO, but a smaller concentration of NOx compared to the other four fuels as well as a significant reduction in particulate matter. Yet, the alcohol fuels have limitations as ‘drop-in’ fuels due to operability constraints. Regarding the flame shape and spray distribution data from the imaging characterization, the images between the fuels were similar.
Faculty Advisor:
Prof. Tim Lieuwen