Analysis Of Wind Flow And Wind Effect On Low-Rise Gable Roof

Wind damage is a main natural disaster in our country, especially in the southeast coastal area. Researches on typhoon show that roof is a vulnerable part of a gable roof building under wind action. Therefore, it's of importance to analyze and understand the wind flow and wind effect around a gable roof.Based on computational fluid dynamics techniques, the wind field around a low-rise gable roof with cornices is investigated with a stabilized fluid finite element method by introducing the Reynolds-averaged Navier-Stokes equations and the Spalart-Allmaras turbulence model. The flow field and the wind pressure distribution around a low-rise gable roof depending on the roof slope and the length of cornices are numerically simulated and systematically analyzed. The results show that the length of vertical cornice has a great impact on wind load shape coefficients and the wind pressure distribution around the roof while that of horizontal cornice doesn't affect the pressure distribution. Adding vertical cornice or both horizontal and vertical cornices can greatly change the wind pressure distribution on the roof, and the negative pressure on some areas obviously increases.Considering the roof slope and the height-width ratio of the building as control parameters, the wind field around gable roof under different wind directions is numerically simulated by using FLUENT software. The results show that wind pressure coefficients of the roof vary with both the wind direction and the roof slope, and the negative pressure is generated by flow separation. The height-width ratio has little influence on wind pressure coefficients and it can just slightly change the wind pressure on some areas of the roof.