ヘルムホルツ共鳴現象を利用した体積計測法の 極低温流体への応用に関する研究

抄録

Near feature, cryogenic propellants including liquid hydrogen, liquid oxygen and liquid natural gas will be handled on orbit for space transportation systems. Measurement of liquid volume under the micro-gravity condition is an important aspect of the space technology. In the present study, Helmholtz resonance is applied to measure a liquid volume of nitrogen in order to conˆrm the applicability of this measurement technique to cryogens. It was found that the measurement of spatial temperature distribution in the container is needed to obtain accurate liquid volume because the velocity of sound has strong temperature dependency. The velocity of sound is an important factor to obtain the Helmholtz resonance frequency. And we also found that the liquid stabilization technique is necessary to apply this technique to cryogens because the deformation of a liquid/vapor interface is largely influenced on the spatial temperature distribution