Yttrium samples were levitated in an electrostatic levitator and their radiation intensities at their melting temperature were measured by spectrometers over a wide wavelength range. By comparing the measured intensities with those of a blackbody, spectral hemispherical emissivity values were calculated. The total hemispherical emissivity of yttrium at its melting temperature was calculated by integrating the spectral hemispherical emissivity and was found to be 0.32. The constant pressure heat capacity was also calculated using time-temperature data and was found to be 37.8 J·mol-1·K-1 at 1795 K.
Toward the on-orbit experiments on liquid-gas behaviors in Space exp. range
closed vessels aboard the International Space Station (ISS), a series of
ground experiments were conducted by use of the engineering model
(EM). Target phenomenon was a sloshing in a rotationally oscillating
rectangular vessel. Numerical model was developed to predict the motion
of the liquid with the free surface by applying the level-set method
and continuum surface force (CSF) method. Based on the prediction of
the resonant frequencies in the laterally oscillating rectangular vessel,
our numerical model well reproduced the ground-experiment results
with n-hexane as the test liquid, whereas significant discrepancy was
found against those with water. We successfully reproduced the sloshing
of water in the EM by proposing another numerical model with small pinning plates to prevent smooth motion of
the contact line on the side walls.