Study on mixing process of two component gases in vertical fluid layer

-Effectiveness on natural convection and molecular diffusion

Abstract

The purpose of this study is to investigate the effect of natural convection and molecular diffusion on the mixing process under the stable density stratified fluid layer of two component gas. An experiment has been carried out to investigate a control method of natural circulation of air by injection of helium gas. The experimental apparatus consists of a reverse U-sharped vertical slot and a storage tank. The left side vertical slot consists of the heated wall and cooled wall. The right side vertical slot does not insert anything. Experimental results regarding mixing process of two component gases in vertical fluid layer were as follows. The heavy gas was transported to the slot by the molecular diffusion and natural convection. As time elapses, natural circulation of heavy gas suddenly occurs through the reverse U-shaped slot. As a result of experiments, the onset time of natural circulation is affected by not only molecular diffusion coefficient but also the strength of natural convection. When the helium gas is injected into the channel, it is possible to control the natural circulation of air. The onset time of the reproduction of the natural circulation can be varied by changing the injection rate of the helium gas.