Study on thermal stratification of an enclosure containing two interacting turbulent buoyant plumes of equal strength

Abstract The emptying-filling box model with two interacting turbulent buoyant plumes of equal strength is investigated in this paper using theoretical analysis and numerical simulation. Theoretical models are deduced and validated to quantitatively predict the thermal stratification height of an enclosure containing two interacting buoyant plume sources with different separations between the two plumes. The variation in the thermal stratification height with the separation between the two plumes is validated by numerical simulation. A threshold for the separation between two plumes is defined to determine whether the two buoyant plumes in the enclosure are interacting or independent, which is also confirmed by numerical simulation. Simultaneous equations containing height difference between the top and bottom openings of the enclosure and effective area of the top and bottom openings of the enclosure are proposed to predict the threshold. These results can be used as a reference on natural ventilation design for buildings with interacting heat sources to make use of the effect of indoor thermal plumes and create a suitable indoor environment.