Study of technique for measuring liquid volume using acoustic wave on orbit

Abstract

Near feature, cryogenic propellants including liquid hydrogen, liquid oxygen and liquid natural gas will be handled on orbit for space transportation systems. It will be absolutely needed to measure the liquid volume under the micro-gravity condition. In the present study, Helmholtz resonance is applied to measure a liquid volume. In order to confirm the applicability of this measurement technique to cryogens, the micro-gravity experiment using liquid nitrogen was carried out. We report the experimental results and propose a measurement system for the practical application on orbit.