Eko Siswanto, Hiroshi Katsurayama, Yasuo Katoh
Instability on condensate propagation in porous bed of glass-beads and alumina-balls media is observed experimentally. This study is done by streaming the varied temperature of saturated humid-air over the media. Towards the humid air temperatures, the ambient temperatures are restrained on constant 308 K and on constant-ratio, respectively. By calculated evaluation, it is clear that the condensate propagation is in Darcian regime. In this theoretically stable regime, however, based on visualization and on modified Lyapunov-exponent for the longest finger, the propagation lies respectively on stable-dominant, unstable-dominant, and temporalchaos behavior. It is known that the instability propagation is not only depended on porosity and permeability, but also controlled by wettability of the porous media and concentration gradient of the condensate in the porous layer. From this study, it is also evident that the ambient temperature plays a key role on generating the concentration gradient.
Yamaguchi University, Science and Engineering, Mechanical Engineering Dept., Ube, Yamaguchi 755-8611, 2-16-1 Tokiwadai, Japan; Brawijaya University, Mechanical Eng. Dept., Malang, Indonesia
