I have become plot, the visualizer of the thermal gradient

Author: Chinmaya Joshi | Major: Mechanical Engineering | Semester: Spring 2025

When you’re working with nuclear propulsion systems, especially the kind that might one day power long-distance space missions, you end up with a lot of heat. That heat needs to be removed efficiently, or it could damage sensitive components or the structure of the spacecraft. The challenge is designing a cooling system that is not only effective, but also lightweight and reliable. That’s where this project came in.

I worked on developing titanium-encapsulated pyrolytic graphite radiator fins. Pyrolytic graphite is a form of carbon with incredibly high thermal conductivity in one direction. It can move heat extremely well along its surface. Titanium, on the other hand, is strong and light, which makes it perfect for aerospace applications. The idea was to combine the two into a radiator fin that could transfer heat quickly and stand up to the harsh environment of space.

A big part of the project involved figuring out exactly how pyrolytic graphite behaves under heat. I needed to measure how well it conducted heat both across its surface and through its thickness. That meant building and upgrading a thermal resistance tester that could give me precise, reliable results. I spent months improving the setup, fixing alignment problems, improving insulation, and applying thermal paste to reduce measurement error. I also wrote code in Python to analyze the data and calculate how much uncertainty there was in each measurement.

By the end of Spring 2025, the setup was working well. I was getting consistent data and had made huge progress from where I started. A journal paper is currently in the works that explains the updated testing method and how it improves on older approaches.

This entire process would not have been possible without support from Dr. Han Hu. He helped me troubleshoot problems, think critically about the results, and keep the project moving forward. I also got input from other students in the lab and professionals in the field, including researchers with NASA connections. Their advice helped me improve both the experimental design and the way I interpreted the results.

The Honors College Research Grant made all of this possible. I used the funding to buy important materials, including thermal interface pastes, insulation, and parts for the testing rig. I also used it to explore different titanium 3D printing methods for building the actual radiator fins. Without that funding, a lot of the testing and development would have been delayed or impossible.

This project pushed me in a lot of ways. I learned how to plan and carry out a research project from beginning to end. I got more confident using technical tools like LabVIEW and Python. I learned how to deal with uncertainty in measurements and how to design experiments that actually give useful data. I also developed a better understanding of how materials behave in real thermal systems, especially under tight constraints.

One of the toughest parts of the project was measuring how pyrolytic graphite conducts heat through its thickness. Because of its internal structure, it behaves very differently in that direction, and the measurements are sensitive to small errors. I had to completely redesign the way samples were clamped in the tester to get accurate readings. Working with titanium was also tricky. It reacts easily at high temperatures, so it had to be printed and handled very carefully. I explored different ways to work around that, including testing various printing services and materials.

Now that the project is finishing up, I’m preparing to start my PhD in Aerospace Engineering at the University of Colorado Boulder. My research there will focus on things like wave dynamics, hypersonics, and transition control using advanced materials. The skills and experience I gained during this project will carry over directly. It was great hands-on training in building hardware, testing materials, and thinking like an engineer.

This was one of the most rewarding things I did during my undergraduate years. It challenged me, but it also showed me how much I enjoy solving tough problems and working with real systems. I’m very thankful to the Honors College for giving me the chance to do it.