Experimental Study Of Air Contaminant Diffusion Law In Civil Aircraft Cabin

The existence of contaminant in aircraft cabin can be a serious threat to the health and life of passengers since aircraft cabin is a confined space,so it is very significant to research the diffusion of contaminant within cabins which also contribute to reduce and eliminate contaminant transport in aircraft cabin cause there are so many different sources of contaminant and effect inside aircraft cabins.Aim at a certain type aircraft cabin,the measure methods of different contaminant type are designed relatively,and base on which the air contaminant transport in aircraft cabin is investigated.As for contaminant which is from ventilation,different type of instantaneous and continuous are considered,the transport rule of these two type contaminant under ventilation with different type and rate are investigated meanwhile the effect of different ventilation patterns on ventilation efficiency is investigated base on the method of tracer gas.As for contaminant which is from cabin,the effect of different ventilation and contaminant source location on contaminant transport rule is investigated within valid measurement area.The whole air flow field is measured under different ventilation conditions by PIV and the mechanism of contaminant transport is explained with vortex structure.The effect of contaminant transport caused by ventilation with different types and rates and contaminant positions is figured out by analyzing the rule of contaminant transport and character of air flow field within aircraft cabin.The results showed as below: 1)there is the difference of bleed contaminant concentration among different positions when it came into cabin at the beginning phase while the concentration diffused symmetrically in the cabin and got a peak in a short time which has nothing to do with the ventilation types;2)Mixed ventilation can transfer the fresh air to passengers faster than ceiling ventilation when there is no contaminant,however,it can strengthen the diffusion of contaminant within cabins when there is the contaminant but with a faster elimination rate;3)It is more likely to make contaminant accumulate with a high concentration under ceiling ventilation whilemore likely to transport under mixed ventilation;4)The structure of air flow field is totally different under different ventilation conditions.The different vortex structure is the nature of the various ventilation types and contaminant positions that determine the rule of contaminant transport.