Characterization of H2O transport through Johnson Space Center number 1A lunar regolith simulant at low pressure for in-situ resource utilization

Abstract

H2O transport through a packed bed of Johnson Space Center number 1A (JSC-1A) lunar regolith simulant was examined at relevant temperatures and pressures for in-situ resource utilization (ISRU) on the Moon. Experimentation was conducted over a range of pressures from 50 to 2065\u2009Pa at ∼350\u2009K, corresponding to Knudsen numbers of 0.3\u2009<\u2009Kn\u2009<\u200911. Pressure and temperature conditions were relevant toward ISRU technologies. A piecewise function was used to evaluate transition and Knudsen regime flows. The piecewise model utilized a Knudsen number that predicted the transition point between advective and Knudsen flows. A transition Knudsen number of 1.66\u2009±\u20090.61 and a tortuosity shape parameter of 0.736\u2009±\u20090.13 were determined from non-linear regression, and Knudsen diffusivities of 10.62\u2009cm2·s−1, 10.40\u2009cm2·s−1, and 9.04\u2009cm2·s−1 for packed beds of JSC-1A with porosities of 0.388, 0.385, and 0.365, respectively. The experimental measurements, methodology, and modeling provide useful information for ISRU technologies involving the transport of volatiles (e.g., thermal extraction of H2O).