Numerical Study Of Wind-rain Interaction Effect On Low-rise Buildings

The coastal regions of China are those areas that typhoon often visits. Intensive rainfall always happens before and after the typhoon, rain is given a horizontal velocity component by the wind, striking onto low-rise building facades, which is the primary reason of the destroyed buildings. Previous wind disaster surveys indicate that most destroyed buildings in the disaster are low-rise buildings, include single and group low-rise buildings. Therefore it is highly necessary to grasp the distributing law of wind-rain load on facades and distribution of wind-driven rain for such kind of buildings and the airflow interference between adjacent buildings, moreover, to find out the corresponding wind-driven rain resistant ways.In this paper, numerical simulation method was employed to research action effect of wind-driven rain on the facade of low-rise building that with different wind velocity, different precipitation and different roof configuration. On the basis of the existing research achievement, the basic equations and numerical discretization and solution approaches for turbulent wind flow based on the averaged Navier-Stokes equation and the k-εturbulence model are established, and introduce the rain fall model, discrete phase models(DPM). Then a series of working condition such as different wind velocity, different wind direction and different precipitation to further study the action effects of wind-driven rain, and compared with different roof configuration buildings, include non-cornice and flat roof. Research shows that the load induced by wind-driven rain has obviously affected the facade of low-rise building. The additional load can reach wind load more than 30%.Secondly, the distribution of wind-driven rain was fully simulated numerically and analyzed concerning two gable roofed buildings bearing same geometrical shape along with varying distance with different array. Research shows that distribution law of wind-driven rain on facade of low-rise building has significantly different from single building with the distance variation. Finally, the wind-driven rain on buildings complex, which consisted of three low-rise buildings with gable roof, have been predicted using the numerical simulation technique. The distribution law and behavior of wind-driven rain on the facade of low-rise buildings complex induced by the effect of multi-building interaction were analyzed in detail. The distribution law of wind-driven rain of group effect is comparatively complicated.The results obtained in this paper could be applicable to structural design of gable roofed buildings under wind and wind-driven rain, and guide the design of resistance of wind and rain on facades.