## 2 Materials and Methods  
### Experimental Setup  
The experimental campaigns were carried out in an experimental chamber with dimensions of 3.8 m \(\times\) 2.6 m \(\times\) 2.5 m (L \(\times\) W \(\times\) H), where we reproduced a configuration of a small part of an aircraft cabin, including 2 rows, each with 2 passenger seats and a general ventilation configuration similar to that in Figure 2. One of our advanced prototype thermal manikins [51] was placed on one seat. Three thermal dummies with advanced control system were placed on the three other seats, simulating a total of 4 passengers (Figure 3). The purpose of this experimental setup was to perform rigorous measurements of the interactions between the thermal plumes of the four passengers, as well as the general ventilation system. Thermal plumes were characterized with and without the functioning of the general ventilation system using infrared (IR) thermography, arrays of thermocouples (Figure 4), and particle image velocimetry (PIV) measurements. The thermocouples were calibrated  
Figure 3: Experimental setup for PIV measurements. prior to the experimental campaign using a thermostatic bath (Lauda Eco Silver). For data logging from the thermocouple array, we used an ALMEMO 710 acquisition system. During thermal plume measurement, the air temperature at several points of the test chamber, as well as the wall temperature, was recorded with PT100 temperature sensors (see Figure 5) connected to a data-acquisition device (ALMEMO 710). Some data-acquisition devices were placed in the center of each wall (\(t_{1}\)-\(t_{4}\)), at a height of approximately 1.5 m, including floor (\(t_{6}\)) and ceiling (\(t_{5}\)), while others were used to measure the ambient air temperature and the air in the diffuser (\(t_{a1}\) at the bottom of the room, 1 m from the floor, and \(t_{a2}\) at 2.1 m). Figure 4: Experimental setup for thermal measurements using IR thermography and an array of thermocouples. Figure 5: Evolution of air and surface temperature during thermal plume measurements, showing the stability of the thermal environment. A Flir E6 IR camera was used to periodically check the wall temperature of the experimental chamber and the temperature of the segments of the manikin. The Flir E6 IR camera has an accuracy of \(\pm\)2% and a thermal sensitivity of <0.06 \({}^{\circ}\)C. Infrared thermography (IR) measurements were also taken with the Flir E6 IR camera to determine the gradient temperature of the thermal plume. A thin, black cardboard sheet was fitted on top of the manikin's heads (Figure 4). A grid of measurement points was placed above the experimental manikin's heads, with 50 mm distance between each of the grid's measurement points (marked using black metallic paint as seen in Figure 4). The emissivity (\(\epsilon\)) for the IR camera, while reading on the black duct tape, was set to 0.98, and 0.75 while reading on the aluminum foil covering the whole manikin. The black cardboard with the grid provided a scale for measuring distances. Particle image velocimetry (PIV) measurements were taken to determine the velocity profiles of the thermal plumes. The PIV system is composed of one high-sensitivity Flow Sense EO camera with 4 \(\times\) 10\({}^{6}\) pixel resolution and a Dual Power 200 mJ laser with a wavelength of 532 nm. The acquisition frequency of the PIV system, between two pairs of images, was 7.5 Hz. The image calibration gave a spatial resolution of 182 um per pixel, which corresponds to a 365 \(\times\) 365 mm\({}^{2}\) field of view. In order to see the airflow, the entire room was seeded with a fog generator that used olive oil. An air compressor was used to supply the fog generator with compressed air. During PIV measurement, the fog generator and the ventilation system were turned off, and the exhaust grilles were sealed. The laser was placed on a rack system, perpendicular to each manikin's head, while the camera was placed on the left side of the laser, rotated at an angle of 90\({}^{\circ}\), to observe the laser plane.