A novel mode of air supply for aircraft cabin ventilation

Aircraft cabin ventilation is essential during commercial passenger flights. Efficient fresh air delivery has become an important research issue in the field of HVAC. This study proposes a novel mode of air supply, which has the potential to improve ventilation performance, without increasing the fresh air supply rate. The velocity at the cabin inlet is set to follow a square-wave signal. Under this periodic supply condition, the fresh air jet, after entering the cabin, appears to oscillate. This motion is able to continue, for an interval of time, during which the mixing between fresh and residual cabin air is enhanced, if the periodic supply signal is properly defined. Consequently, when compared to a traditional steady supply air delivery at the average rate of the periodic supply, the periodic condition may achieve better ventilation, as indicated by the performance measures considered in this study. Note that the reported improvements may need further justification by field tests, due to the somewhat limited capability of a numerical simulation to fully reflect the complexity of real boundary conditions.

► Investigated cabin airflow variations due to change of fresh air supply flow rate.
► Proposed a novel air supply condition where the flow rate varies as a square wave.
► Evaluated CO2 and mean age of air distribution under the novel supply condition.
► By applying the novel supply condition, ventilation performance is improved by 10%.