Impact of Clothing, Breathing and Body Posture on the Shaping of a Thermal Plume above a Human

The impact of clothing, breathing and body posture on the thermal plume above a thermal manikin was investigated. Measurements of air velocity and temperature above the manikin were performed at four different heights above a sitting and a lying manikin. The results obtained from tests above the sitting manikin show an inverse proportion between the thermal insulation of clothing and the air velocity in the thermal plume. Air velocity in the thermal plume with the breathing function switched on equalled 90–98% of the values obtained for non-breathing experiments. The use of the breathing function caused an asymmetry of the thermal plume above the manikin’s knees. The presence of an area of increased velocity and temperature originating from the breathing process was observed (“warm cloud”). Results obtained from the measurements above a lying manikin confirmed the impact of thermal insulation on the thermal plume, however a reverse relationship was observed at the lowest measurement height with the breathing function on. The existence of three areas influencing the thermal plume was revealed - head, torso, feet. For the lying manikin the air velocity increased by 6–13% when the breathing function was used in relation to non-breathing tests.