Abstract
A gas-droplet mixture flow has been investigated by a light extinction and scattering method in an expansion-shock tube. A mist flow was produced by an adiabatic expansion of a mixture of water vapor and N2 gas. The expanded mixture is at 190 K and 13 kPa. A shock wave propagates in the mist. The propagation in the gas-droplet mixture was observed by an optical nethod. The fundamental setup of optical observation is a kind of spatial filtering method. A knife edge was replaced by the spatial filter, which was designed to pass a transmitted light and cut scattering light. The recorded image was converted to a digital one by the film scanner with a high resolution. The variation of the droplet radius was obtained from the recorded photograph using a suitable procedure. On the other hand, the ratio of the number density of the mist across the shock wave was obtained from the image of the photograph experimentally obtained. The computed result was compared with the experimental one. The experimental results show a good agreement with the computed one.
