Application of CFD in Modelling Wind-Induced Natural Ventilation of Buildings - A Review

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. The review showed that the whole-domain approach has been more popular than the domain-decoupled approach, and with efficient computing algorithms, grid generation techniques and advances in hardware technology, can overcome the computational overhead it incurs during application. CFD has also allowed the concept of stream tube and the local dynamic similarity model (LDSM) to be used in practice. These concepts have helped in the fundamental understanding of wind-driven natural ventilation and in distinguishing flow through large openings from that of "cracks". An important and practical approach for natural ventilation design and analysis is the integration of CFD with other simulation programs such as Building Simulation (BS) and Geographic Information Systems (GIS). Apparently, CFD is increasing its importance in sustainable building design and it is expected that more complex naturally ventilated buildings will be designed and analysed as CFD techniques continue to improve.