Ventilation similarity of an aircraft cabin mockup with a real MD-82 commercial airliner

Most experimental studies on the aircraft cabin environment were conducted in aircraft cabin mockups. The ventilation differences between the cabin mockups and real cabins is always contentious and has not been identified. Measurements were made to determine the ventilation differences in two cabin facilities with the same single aisle layouts and similar diffuser structures, an MD-82 commercial airliner and a cabin mockup based on the Boeing 737. The ventilation performance of the two cabins, including the ventilation rate, mass balance and air velocity, were compared based on the data collected by ultrasonic anemometers (UAs). The result showed that the two cabins met the requirement of the ASHRAE standard, and the cabin mockup was sufficient to reflect the longitudinal flow in real cabins. The air velocity fields measured by UAs and 2D particle image velocimetry (PIV) in the cabin mockup were compared. Suggesting that the difference introduced by different measurement methods could be ignored, and the simplified diffuser geometry in the cabin mockup had no significant effect on the airflow. The requirement to maintain a certain type of airflow pattern in the cabins was analyzed by calculating the modified Reynolds number (Re) and Archimedes number (Ar), and it was found that the cabin mockup had similar air distribution features as the MD-82. These similar phenomena and similitude criteria verified that this cabin mockup is accurate enough to represent a real cabin environment and could be better used in the study of ventilation.