Fluid systems play a large role in life support, environmental controls, and thermal control systems. While there are databases and models of fluid flows in microgravity, there is no empirical data, nor models which examine fluids in partial gravity, such as Lunar or Martian gravities. In order to design the next generation of life support systems, the Aerospace Human Systems Laboratory (AHSL) at Texas A&M University plans to investigate fluid physics in variable gravity levels.
STS060-301-003 (3-11 Feb 1994) — Astronaut Kenneth S. Reightler, STS-60 pilot, processes samples in a centrifuge aboard the SPACEHAB module. Photo Credit: NASA.
The aim of Paul Burke’s research is to analyze the effect of gravity level and centrifugal effects on the orifice nucleation, growth, detachment, and movement of nitrogen bubbles in water and silicone oil. Understanding bubble nucleation, growth, and detachment, specifically in microgravity and partial gravity, is a critical component of designing more efficient and lighter two-phase flow thermal management systems.
In microgravity models, surface tension forces and effects dominate the bubble nucleation, while in terrestrial models, the buoyancy forces dominate the bubble nucleation. The project will produce experimentally verified bubble nucleation models which account for surface tension, buoyancy forces, and centrifugal effects to better understand partial gravity fluid physics and to be able to scale terrestrial experimental results across gravity levels.
Paul aims to utilize Techshot’s Multi-use Variable-gravity Platform (MVP) system to perform this experiment. The MVP, is a small centrifuge on board the International Space Station capable of creating artificial gravity up to 2 g on timescales of multiple weeks.