Vortex shedding

Throughout history, natural ventilation has remained the preferred choice for the majority of residential buildings, while, in commercial buildings, natural ventilation went from being the single option to somewhat of a lost art as mechanical ventilation systems and air conditioning became the standard during the second half of the twentieth century. Recently, as a result of environmental concerns, in particular the greenhouse gas emissions from buildings, interest in natural ventilation in commercial buildings has seen a resurgence.

The three-dimensional wind environment in Lanqiying community of Beijing city, which is complicated due to the dense distribution of the highrise buildings, is investigated by computational fluid dynamics method. The turbulent flow past the buildings is simulated by solving the incompressible Reynolds-averaged Navier-Stokes equations. Both the reverse flow between the buildings and the ecirculation of the wake can be observed. The spectrum analysis of aerodynamics coefficient are successfully obtained and compared with the twodimensional results.