Researchers from Purdue University and NASA’s Glenn Research Center have completed a groundbreaking experiment on the International Space Station, shedding light on how boiling and condensation work in the microgravity of space. The findings could pave the way for more efficient thermal management systems in future spacecraft and habitats on the Moon or Mars.
Tackling the Challenges of Thermal Management in Space
Controlling temperature in the extreme conditions of outer space will make this future price worth it.
Unlike its planet, the surface of the moon can change dramatically from as cold 410 degrees Fahrenheit to 250 degrees Fahrenheit. To establish a human presence on the moon, thermal management systems also would need to work effectively in this temperature range.
In a similar way, as we push deeper into space, the requirements for cryogenic fuel depots and advanced propulsion systems such as nuclear fission or Rankine cycle heat engines will necessitate a more robust understanding of fluid behaviors in microgravity. These systems will also require highly efficient cooling systems that can work in a zero-gravity environment.
Unlocking the Secrets of Boiling and Condensation in Microgravity
Difficulties with such devices are investigated as part of the Flow Boiling and Condensation Experiment (FBCE), headed by Purdue’s Issam Mudawar.
A phenomenon known as flow boiling, in which heat is removed by allowing a liquid to flow and then boil into a gas that phase changes and carries the heat away from the surface, has been widely investigated on Earth. But very little was known about how this process behaved in the microgravity of space.
“Over the past century, we have acquired knowledge on the ground of heating and cooling systems, but that [knowledge is] ineffective for radiators in weightlessness,” said Mudawar.
The FBCE experiment was conducted on the International Space Station and included two Purdue-designed test modules, one for flow boiling and one for condensation, integrated with a fluid system designed by Purdue researchers and NASA Glenn. That, in turn, enabled researchers to carry out a virtually unlimited series of ground-based experiments before and after the launch to gather an enormous amount of data about how boiling modes and condensation behave in microgravity.
Conclusion
The data will allow researchers for the first time to study boiling in viciously low gravity, where natural convection is so weak as to be almost nonexistent. This insight is expected to play a critical role in the design of space more efficient thermal management systems used on future spacecraft and habitats, as well as in advanced propulsion technologies. Knowledge of these fundamental physical processes in the exotic environment of space, unlocked by FBCE is paving the way for future exploration and enabling the development of improved systems to sustain human life and activity in space.
