Evaluation of dynamic airflow structures in a single-aisle aircraft cabin mockup based on numerical simulation

The airflow distribution characterised by different large- and small-scale eddies in the aircraft cabin is the most important factor to maintain passengers' thermal comfort and to remove contaminants. The airflow distributions in narrow-body aircraft cabins are based on the principle of mixing ventilation. Opposing jets from air diffusers can cause stream deflection and oscillation, which results in the asymmetry of large-scale instantaneous airflow structures. This dynamic airflow structure is very important for analysing time series parameters. Therefore, this study applied numerical simulation to examine the oscillation and asymmetry of instantaneous airflow field structures and phase space reconstruction and used spectrum analysis to evaluate the oscillation amplitude and period of dynamic airflow structure. We also studied the factors that influence the dynamic airflow structure, such as air supply speeds, air supply angles and the strength of the thermal plume. The results showed that as the air supply speed increased, the swing amplitude of the instantaneous airflow structure increased, while the period decreased. The air supply angle affected the jet attachment and collision angle, which in turn affected the swing amplitude and period. The thermal plume restrained the formation of large-scale swings and contributed to the appearance of small-scale structures.