Jensen, Rasmus Lund

Lia, Yuguo

Litewnicki, Michal

Liua, Li

Nielsen, Peter V.

Zajasb, Jan

English

The Thermal Plume above a Human Body exposed to different air distribution strategies Li Liua, Peter V. Nielsenb, Yuguo Lia,  Rasmus L. Jensenb, Michal Litewnickib, Jan ZajasbaDepartment of Mechanical Engineering, the University of Hong Kong, Pokfulam Road, Hong Kong SAR, ChinabDepartment of Civil Engineering, Aalborg University, Sohngårdsholmsvej 57, 9000, Aalborg, DenmarkThis study compares the impact of air distribution on the thermal plume above a human body in indoor environments. Three sets of measurements are conducted in a 3.17 m (l) × 2.64 m (w) × 2.93 m (h) test room with different ventilation conditions, i.e., no ventilation, displacement ventilation and mixing ventilation. One breathing thermal manikin standing in the room is used to simulate the human body. Vertical temperature gradient in the room is measured to characterize the stratified environment. Long-time average air velocity profiles at locations closely above the manikin are taken to identify the wandering thermal plume. The results reveal that the thermal plume above the manikin with displacement ventilation is the weakest. Unlike the axis-symmetrical Gaussian distribution of the velocity profiles in other two cases, the velocities along the horizontal axis to the nose do not vary a lot. The peak value of the average velocities is nearly one third of those in other two cases. It may indicate that less contaminant would be transmitted from lower part to breathe region of the occupants by the thermal plume in a displacement ventilated room. It is also found that the variance of the velocity distribution above the manikin with mixing ventilation is lower than that with no ventilation. The air distribution with mixing ventilation may mix round the thermal plume and change the fate of the contaminant. CFD simulation has also been carried out and it agrees well with the measurement results.  Keywords: plume, air velocity, temperature gradient, full-scale measurement

The Thermal Plume above a Human Body exposed to different air distribution strategies

https://vbn.aau.dk/ws/files/19052536/The_Thermal_Plume_above_a_Human_Body_exposed_to_different_air_distribution_strategies_

The Thermal Plume above a Human Body exposed to different air distribution strategies

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