微小重力環境におけるナノ流体による熱対流に及ぼす重力変調の影響

抄録

Three-dimentional numerical analysis was conducted on the natural convection heat transfer of nanofluids under microgravity environment with G-jitter. G-jitter is modeled with sinusoidal oscillation of gravity, and the residual gravity and amplitude are the same as 10^-3 G. Nanofluids is a suspension composed of water and Cu nanoparticles. Shallow rectangular chamber is filled with a nanofluids. The bottom wall is heated and the top wall is cooled, and the periodic boundary condition is applied to other boundaries. Rayleigh number is 3×10⁶, volume fraction of suspensions are 0, 0.01 and 0.05. The findings obtaind are summarized as follows: Thermal plume is observed in the chamber, and thermal convection repeats occurrence and disappearance to follow the gravity modulation. The local heat transfer rate increases at the bottom wall where downward flow collides. Convective heat transfer decreases with increasing volume fraction since viscosity of nanofluids is increased. When the volume fraction was 0.01, heat transfer characteristic is the best in a parameter of this analysis.