MIXING VENTILATION BY IN-SEAT AIR OUTLETS FOR SINGLE-AISLE AIRCRAFT

Kurzfassung

In recent years, alternative ventilation systems for aircraft cabins have attracted the attention of scientists and aircraft manufacturers due to their potential to save energy and increase thermal comfort. Therefore, two alternative ventilation systems were investigated separately and in combination in the Dornier 728 test facility of the German Aerospace Center in Göttingen: Firstly, in-seat ventilation (ISV), where the fresh air flows vertically into the cabin in the immediate vicinity of the passengers through air outlets attached to the back of the seats. Secondly, floor-based cabin displacement ventilation (CDV), which is based on low supply air velocities through dense membranes under the seats. As a third variation the systems were combined to form a hybrid ventilation system. The measurement techniques were selected and designed to quantify and evaluate the following parameters: boundary conditions, cabin air temperature, efficiency of the ventilation concept, flow velocities, 3D flow measurements and thermal comfort. The aim of this study is to create optimal thermal conditions for passengers using a combination of CDV and ISV. Furthermore, it was investigated whether the combination of the two ventilation technologies could create mixed ventilation in the single-aisle cabin. The results showed that neither CDV nor ISV alone meets the comfort requirements. However, combining the ventilation systems produced good results for the ventilation of a single-aisle aircraft. Despite the high inflow velocities associated with ISV, no threshold values were exceeded near the passengers. Furthermore, ISV reduced the uncomfortable temperature stratification in CDV. Combining the systems resulted in equivalent temperatures that were neither too warm nor too cold for all body parts.