NASA’s future deep-space missions, including journeys to Mars, require spacecraft to refuel using cryogenic propellants that must remain at extremely low temperatures. Cooling systems maintain these fuel temperatures, relying on heat exchangers to remove excess heat. Traditional heat exchangers are often heavy and bulky, problematic for space travel where weight minimization is critical. While NASA aims to increase recuperator performance, increasing their size is not ideal.
We designed a recuperator using an internal coral-like porous structure to address this challenge. In our design, a thin wall separates the channels for hot and cold fluids, allowing them to intertwine without mixing. The complex geometry provides increased surface area, enabling more heat transfer in the same volume. Research showed that a coral-like porous heat exchanger core with diamond-shaped channels offers the best heat transfer performance.
We intended the design for 3D-printing, as the porous structure is too complex for traditional manufacturing methods. We printed multiple scaled- down versions in plastic and nylon to verify the design geometry. We also printed a final metal version to test heat transfer performance and pressure retention capability.
Our results indicate that coral-like porous recuperators are theoretically more efficient than current designs. However, due to current cost and size limitations of metal 3D printing, further development is required before this technology can compare to NASA’s other designs.
