Practicing my passion for aviation and aerospace engineering
Author: Joshua Mora Sanchez | Major: Mechanical Engineering | Semester: Fall 2024
My undergraduate research journey began in the summer of 2023. I worked with Dr. Han Hu from the mechanical engineering department as a research assistant at his Nano Energy and Data-driven Discovery (NED3) laboratory. Although a good part of my research was done that summer, I worked on developing and characterizing a manifold microchannel (MMC) heat sink for the thermal management of highly dense power electronics during the fall of 2024. My goal for the fall semester focused on doing extensive critical literature review and obtaining valuable results from the MMC heat sink tests to support electric aircraft development.
The electrification of aircraft is ultimately limited by the ability to cool down energy conversion electronics, so by providing a compact, and highly efficient heat sink, I hope to promote the development of electric aircraft. My contribution to power electronics will have a significant impact on the use of more sustainable, renewable energy sources in order to reach the zero-CO2 emissions goal for 2050. In the future, I hope to conduct a PhD in aerospace engineering to keep advancing green technologies for urban air mobility (UAM), and ultimately, I wish to work in the aerospace industry.
The miniaturization of microprocessors and power electronics poses significant thermal management challenges. For example, modern computer chips generate heat fluxes of approximately 100 W/cm², far exceeding the capacity of air cooling. This intense heat generation can cause thermal and mechanical failures in electronic devices, underscoring the urgent need for effective cooling solutions. Liquid cooling with microchannel heat sinks is a promising approach for high-power applications. However, traditional straight microchannel designs face issues like high pressure drops and poor temperature uniformity.
To overcome these limitations, I decided to work on a 3D MMC heat sink fabricated via metal additive manufacturing. The innovative flow structure and microchannels reduce flow length, minimizing pressure drops and temperature imbalances. The heat sink is produced using direct metal laser sintering with 6005 aluminum alloy. Its performance was evaluated through flow tests in an in-house liquid test loop, revealing a thermal resistance as low as 0.51 K/W and a pressure drop of 1.5 kPa at flow rates up to 0.4 L/min.
This design offers enhanced thermal performance and cost efficiency, benefiting applications such as wafer-scale engines for supercomputing, radar system amplifiers, and high-voltage converters, inverters, and transformers used in power grids and electric propulsion systems.
Over the fall semester, I developed an advanced cooling device while gaining invaluable experience in collaboration, regular engagement with my professor, and project management. While I designed most of the heat sink’s features, my mentor, Dr. Han Hu, guided me in shaping the research framework. Dr. Hu also helped me connect with internal and external labs to access specialized expertise, such as selecting materials optimized for thermal resistance during flow tests. I used the flow loop developed by Stephen Pierson, fellow research assistant at the NED3 lab. I also worked in tandem with Chinmaya Joshi, who’s research focus was on additive manufacturing processes at the moment, in order to assure manufacturability of my parts. As the design engineer, I led the iterative improvement of heat sinks, analyzing data from literature reviews and conducting flow loop tests. By the end of the project, I had collaborated with a multidisciplinary team and contributed across all phases, from concept design to manufacturing, testing, and results interpretation.