Investigation of thermal plume and thermal stratification flow in naturally ventilated spaces with multiple heat sources

Abstract

Natural ventilation driven by thermal buoyancy is an energy-efficient approach to reduce indoor air temperature. In practice, there are generally many heat sources in most naturally ventilated buildings. Therefore, the motion of the thermal plume and the effect of multiple equidistant distributed point heat sources on the stratified flow were studied in this paper. The formula for calculating the thermal stratification height of multiple heat sources was derived and validated. The influences of heat source spacing, heat source surface emissivity and other factors on thermal stratification flow were analysed. In addition, the discrete threshold of multiple plumes was obtained, which could be used to estimate whether the thermal plume is independent. Moreover, the variation in the effective entrainment coefficient of multiple plumes with the heat source distance was analysed. These results can provide a reference for designing natural ventilation for buildings with multiple heat sources and creating a suitable indoor environment.