A Novel Testing Protocol for Evaluating Particle Behavior in Fluid Flow Under Simulated Reduced Gravity Conditions 2009-01-2359
A terrestrial analog device was developed to test the performance of a proposed lunar regolith-based water filtration design. To support this study, the flow behavior of tracer particles passing through a glass bead media filter was evaluated on NASA's reduced gravity aircraft in simulated microgravity and lunar gravity environments. The flight results were then compared to tests conducted using a novel application of a clinostat tilted ∼10 degrees from horizontal to simulate a lunar gravity vector fraction (1/6 of Earth's gravity, or 0.17g) acting axially on the fluid system.
Phase I was designed to examine large particle fluidization and sedimentation characteristics, and showed that with relatively large particles, a sedimentation layer formed in the inclined clinostat similar to the true reduced gravity environment. Phase II was conducted with smaller glitter particles used as tracers and indicated that fractional (partial) gravity settling can be simulated in an inclined rotating environment, with the most accurate settling velocity achieved at lower RPMs. The strongly correlated linear relationship between RPM and settling velocity indicates a high level of confidence in the analog, which can potentially be applied to other inclined clinostat studies.
In general, the inclined clinostat concept shows promise as a simulation tool for evaluating expected particle behavior under fractional gravity conditions, and may be feasible for evaluating numerous applications intended for the Moon, Mars or other partial gravity environments.