Study on natural and cross-ventilation performance of detached house model considering wind flow fluctuation

Abstract

The driving force behind natural cross-ventilation is outdoor wind. The indoor airflow distribution and flow rate under cross-ventilation vary greatly because the direction and velocity of wind changes constantly. Thus, cross-ventilation is said to be an unsteady fluid phenomena. Recently, unsteady fluid phenomena have been analyzed by using large-eddy simulation. In this study, a new evaluation method that considers flow fluctuation for natural cross-ventilation is proposed. The evaluation results for the performance of this unsteady natural cross-ventilation model are reported. Consequently, in Cases 2 to 4 wherein no ventilation occurs in a time-averaged flow field, there are unsteady ventilation phenomena. In cases 2 to 4, the effective ventilation rates under unsteady flow are approximately 10% to 20% of those in Case1.