Abstract
Cross ventilation in interior spaces is a commonly adopted means of providing natural ventilation in Japan during moderate seasons, including summer. Cross ventilation is occurred by interaction that caused by the airflow in interior and exterior rooms and the pressure distribution of the building walls. The airflow distribution varied depending on the outside wind direction and velocity. Moreover, the outside wind turbulence affects cross ventilation, for example, in the case of two wall openings symmetrical to the wind direction. Cross ventilation is a unsteady-state phenomenon, and in order to understand it better, the wind flow and velocity have to be quantified. This study describes the airflow distribution in a simple cross-ventilated house model by using PIV and a large-size boundary wind tunnel. In this paper, the location of the openings and the wind direction are the experimental variables. The wind speed ratio and turbulent kinetic energy distribution by wind velocity vector of 2 dimensions and 2 components in and around the model are reported. In Case B (two openings placed on opposite walls parallel to wind direction), Case C (two openings placed on windward wall) and Case D (two openings placed on leeward wall), where there is no pressure difference of the building walls as a function of time, it is clarified that airflow moves into and out of the model through the openings in turn due to the outside wind turbulence.
