Pneumatic Conveying of Materials at Partial Gravity

Abstract

This project's goal was to evaluate the feasibility of pneumatic transfer for the movement of regolith (lunar soil) at a lunar base. Operation of pneumatic conveying systems at partial (lunar and Mars) gravity conditions on NASA's KC‐135 aircraft allowed the determination of some key parameters necessary for the design of an operable system. Both horizontal and vertical transfer were studied. In the vertical experiment, the choking velocity for 150 μm glass spheres at lunar gravity was determined to be 1/2–1/3 the velocity required at 1 g. Pressure drops were reduced by roughly the same amount. Choking velocity and pressure‐drop data for runs at Mars gravity were problematic due to the intermittent nature of the experiment. Determination of the saltation velocity in the horizontal run was also problematic, but qualitatively similar results were obtained. Comparison of the partial g results to 1 g behavior and theoretical analysis is made.