27 Mar Thermal Conductivity
The vacuum of space is unforgiving and unlike any environment encountered on Earth. Once in space, astronauts are vulnerable to a number of hostile factors including drastic temperature swings. To protect themselves from the environment of space, astronauts wear an extravehicular mobility unit (EMU) during extravehicular activity (EVA). To achieve thermal regulation within the EMU, the astronaut wears a Liquid Cooling and Ventilation Garment (LCVG). Without the use of an LCVG, the inside of the EMU would create an environment similar to a rainforest due to the expelled body heat.
The cooling garment has gone largely unchanged despite advancements in technology, materials, and physiological knowledge. Kayla Daniels, a University of North Dakota Master student, is applying her knowledge of 3D printing and LCVGs to update the tubing geometry in the LCVG for her thesis. Tubing material and shape are a large part in achieving total body thermal regulation with the LCVG. Cheetah filament provided the durability and flexibility needed for the selected tubing geometries. The printed tubing was integrated into a mock LCVG forearm sleeve which subjects wore while various temperatures of water flowed through the tubing.
The results of the experimentation concluded that off nominal, larger base, tubing geometry performed 22.6% better compared to nominal circular tubing. These results suggest that tubing with a larger base could provide better thermal regulation with the anticipated larger workloads on planetary surfaces. Currently, 3D printing is the most cost-effective way to get the desired tubing geometry with a large, flat base. The next step of Kayla’s study will focus on 3D printing longer sections of tubing and integrating them into a full-body liquid cooled garment.