National Aerospace Laboratory
National Aerospace Laboratory
National Aerospace Laboratory
National Space Development Agency of Japan
National Space Development Agency of Japan
Mitsubishi Research Institute, Inc
Mitsubishi Research Institute, Inc
出版者
宇宙開発事業団
出版者(英)
National Space Development Agency of Japan (NASDA)
The experiments of CDU (Convection Diffusion Unit) of VIBES (Vibration Isolation Box Experiment System) were conducted as scheduled. The first one was executed while running the VIBES system and the second without running the system. G-jitter acceleration was measured by two sets of triaxial accelerometers on board the VIBES and the CDU. Diffusion of OH(-) was measured by color of phenolphtalein by using the fact that phenolphtalein turns color between pH 8 and pH 10. Measured diffusion showed a more than 20 percent faster rate compared to theoretically calculated one. This means that the apparent diffusion coefficient of OH(-) was D(sup *)-2D in the first experiment and D(sup *)-3D in the second, where D is diffusion coefficient of OH(-). Measured g-jitter by the accelerometer on-board the CDU showed a stronger g-jitter level in the second experiment than that in the first. This corresponds that the diffusion in the second was larger than that in the first. This suggests that there exist some convection in the liquid due to g-jitter. With regards to measuring natural convection due to residual gravity, this failed because clear distribution of color could not be obtained. The measured flow from the distribution of color, however, was opposite to that predicted.