Capillary Flow in Porous Media UnderHighly Reduced Gravity InvestigatedThrough High Altitude Parabolic AircraftFlights and NASA Space Shuttle Flight

摘要

We have used a highly reduced gravity environment toremove the masking influence of normal gravity andexamine capillary flow in porous media by combiningexperiments from high altitude parabolic aircraft flightsand from the STS-91 space shuttle flight, with simulationsperformed using a simple finite-difference numericalmodel. These studies involved a range of gravitationalaccelerations, surface tensions, viscosities, wettingpreferences, permeabilities, and pore radii on capillaryflow. Throughout enhanced to terrestrial to highly reduced gravitational accelerations, bead-packexperiments and numerical simulation results providedquite good agreement when the constraining cell wallswere not preferentially wetted by the liquid. When thewalls were wetted by the liquid the simulations providedsevere underestimates of the experimental capillary flowresults, apparently due to pronounced fluid flow alongthe inner cell walls under highly reduced gravityconditions. For sand-pack 1g experiments the numericalsimulations provided reasonable predictions; for nearzerogravity experiments some simulations provided