Experimental investigation of large-scale flow structures in an aircraft cabin mock-up

Abstract

The purpose of this study was to investigate the influence of large-scale circulation on the flow field in a cabin mockup. The velocity was measured by ultrasonic anemometers (UA). Then, this study analyzed the turbulence kinetic energy spectra of the velocity fluctuation signal. The turbulence kinetic energy spectra of the measurement points reflect the flow characteristic of the large-scale circulation in the cabin mockup. The results contribute to the understanding of the role of the thermal plume on the large-scale circulation in the cabin. The large-scale circulation's impact on air quality was also investigated, and the contaminant distribution was measured using tracer gas in the cabin. The two large-scale circulation interactions made the air flow mixing approximately uniform.

Airplane cabin mixing ventilation with time‐periodic supply: Contaminant mass fluxes and ventilation efficiency

“…It should be mentioned that thermal effects from heat sources (e.g., passenger thermal plumes) are not implemented (isothermal conditions). This choice is substantiated by previous studies 19,21,29,57 that showed thermal effects to be of secondary importance compared with the significant impact of the supply jets in opposing‐jet SV configurations. Thermal effects may create a more stable flow and have an influence on the mean flow symmetry to some degree.…”

“…In addition, thermal discomfort may also be caused by the higher cooling effect on the human body when subjected to fluctuating air velocities 108–111 . However, this may equally well provide an opportunity to increase the design temperature of the TPV system (which under SV is usually set low enough to provide sufficient cooling) to counteract the stronger cold sensation, thereby also reducing the energy demand as less cooling of the supply air is needed. Although for opposing‐jet configurations several studies pointed out that thermal effects are of secondary importance 19,21,29,57 due to the dominant influence of the supply jets (Section 1), non‐isothermal conditions should also be examined in which thermal plumes of passengers and conditioning of the airsupply air temperature are considered. Incorporation of heat loads can be important as it is the main factor that determines the required supply flow rate 1,51 .…”

“…Thermal effects may create a more stable flow and have an influence on the mean flow symmetry to some degree. In addition, an increased width of the supply jets (i.e., more entrainment), an increased overall flow velocity, and a higher turbulent kinetic energy of the smaller‐scale flow structures were also observed under non‐isothermal conditions, 19,21,22,25,29 although the prevailing flow patterns remained dominated by the high‐momentum opposing supply jets.…”

Experimental study of the impact of passenger behavior on the aircraft cabin environment

“…The airflow is unstable due to the collision of two jets in the cabin. However, from the point of view of statistics and energy spectrum analysis, turbulent kinetic energy was stable in spatial distribution (Zhang et al 2020). The large-scale circulation (LSC) makes the pollutant mixing almost uniform.…”

Experimental evaluation of particle exposure at different seats in a single-aisle aircraft cabin

“…Due to the uneven distribution of occupants, the cabin layout was not symmetric. In more recent studies [ 24 , 25 ], the cabin was fully occupied by thermal manikins, although the measured airflow and pollutant distribution were asymmetric. To lessen the infection transmission, many airlines have reduced the occupancy density by leaving the middle seats vacant.…”