, M. Suzuki 2

Abstract. Recently, terrorism is one of most daunted dangers in the world. Various terrorisms can come about. Biological and chemical terrors have particularly high mortality rate, and tend to wreak the secondary disaster. For these reasons, research and development of measures for decontaminations are emergent and of key issue on a world scale. One of these requirement is gas decontamination technique. In the system of gas decontamination, the gaseous decontamination agent is supplied to a contamination surface. The gas decontamination does not cause corrosion and rust to the target and has high applicability to non-water-resistant targets. However, the research and development of decontamination technique are of great difficulty, and the experiments are highly risky and also legally-prohibited in many cases. Therefore, in this study, computational fluid dynamics is used to simulate the flow and concentration fields where gaseous decontamination flows in a room which is enclosed by contaminated walls. We investigate the local concentrations of decontamination agent, and find that the introduction of circulators is effective to get the uniform concentration of decontamination agent in the room. Finally, the optimum arrangement of the circulators is proposed