Experimental study of wind-opposed buoyancy-driven natural ventilation.

This paper presents an experimental study of natural ventilation induced by combined forces of thermal buoyancy and opposing wind in a single-zone building. Experiments demonstrated that for a certain range of buoyancy strength and wind speed, two different stable ventilation modes and thus flow rates exist for a fixed building geometry at given buoyancy and wind strength. In these situations, the final ventilation mode and the ventilation flow rate are dependent on the ventilation history of the building. This confirms the theoretical predictions by Li and Delsante (1998) in which multiple solutions were found for wind-opposed buoyancy-driven ventilation. Further, it was shown that the experimental results of ventilation flow rate as well as the turning point between the wind-dominated and the buoyancy-dominated ventilation modes are in good agreement with the theoretical predictions.