抄録
The measurement of liquid volume under micro-gravity conditions is an important aspect of space technology. Cryogenic propellants including liquid hydrogen, liquid oxygen, and liquid natural gas will soon be handled in orbit for space transportation systems. In the present study, Helmholtz resonance is applied to measure a liquid volume. To confirm the applicability of this measurement technique to cryogens, a micro-gravity experiment using liquid nitrogen was carried out. And a theoretical model of a closed system is proposed for the practical application in orbit. A preliminary experiment with water as the test liquid was also carried out to confirm the validity of the model. We successfully detected the Helmholtz resonance frequency and its higher order harmonics. It is confirmed that the measurement method is an effective means for practical application.
