The Generation of Internal Waves by the Movement of Human Body and Their Diffusion in the Displacement Ventilated Room

The displacement ventilation (DV) system with stable and continuous temperature stratification is conducive to energy conservation and indoor air quality improvement. However, the disturbance mechanism of human movement on temperature stratification in the DV system is less studied so far. In this paper, the concept of the internal wave is employed to explain the temperature variation during occupant movement in the DV system. The conclusion is that the moving human can produce two kinds of internal waves caused by air extrusion and air entrainment. The internal wave is anisotropic, and it can only transmit in the occupant moving direction. The extruded air and the entrained air hitting the wall can gain the internal collisional wave in the opposite direction of the moving human. The current study provides new insights into the disturbance of human movement on temperature stratification in the DV system.