Evaluation of Aircraft Cabin Air Quality Considering Breath by People on Board

For the application to optimal design and effective operation of air-conditioning system in an aircraft cabin, we propose an indicator to represent the air quality. It was derived from the result of the large-eddy simulation (LES) of turbulent flow with the immersed boundary (IB) method, which took into account the respiration of passengers. The cabin air quality is defined as an oxygen concentration of inhalation air (OCIA) per each breath. Degree of air renewal in reference volume is a dominant factor of air quality, OCIA. Intensity of time-averaged velocities by cross-sectional components closely correlates with the degree of the air replacement, and becomes the most suitable indicator of air quality. In case of decrease of the intensity, each of two different flow conditions, namely stagnation and circular flow just around a mouth, was found out at the reference volume as inactivation elements of the air renewal.