Stream Tube

This paper reviews the application of CFD for designing and parametric studies of wind-induced natural ventilation. The approaches employed in such applications of CFD are whole-domain and domain-decoupled CFD modelling. The domain-decoupled technique separately analyses the external airflow fields outside and internal flows inside a building. In the whole-domain approach, the outdoor and indoor airflow is modelled simultaneously and within the same computational domain.

Conventional method to predict ventilation rate induced by wind is based on the orifice equationassociated with the discharge coefficient and wind pressure coefficient. In the cross-ventilationphenomena, however, this method has a problem due to the difficulty to predict resistance of thebuilding related with total pressure loss. In this paper, therefore, the stream tube caught by the inletopening is analyzed to investigate the pressure loss due to the transformation (and possiblyconvergence and divergence) of the stream tube.