大跨马鞍屋盖脉动风压谱特性

为研究谱能量与旋涡运动或湍流尺度之间的演变关系,基于风洞测压试验,分析了来流垂直于马鞍体迎风墙面时不同矢跨比和不同迎风面高度下的屋面风压分布特性,以迎风低点、迎风中点和迎风高点3个关键测点为研究对象,揭示了在旋涡作用下的脉动风压功率谱特性.分析表明:风吸力最大值出现在迎风低点附近,且风压变化梯度大;矢跨比对屋面风压的影响主要表现在屋盖后方三分之二区域,且曲率越大风吸力越大;迎风面高度越高其风吸力越大,在迎风低点附近其风吸力变化幅度达到最大;马鞍迎风高点和中点处测点风压谱表现为窄频分布,前缘以低频为主控,后缘高频段能量显著高于前缘,而迎风低点处前缘为宽频分布且随来流向后发展高频能量逐渐增大.

Wind pressure spectrum characteristics of the large-span saddle roof

To study the relationship between spectral energy and vortex motion or turbulence scale, wind pressure distribution characteristics of different rise-span ratio and low height of the saddle roof surface were investigated when the flow was perpendicular to the windward wall through the rigid model wind tunnel pressure tests. Then the study focused on the high point, middle point and low point wind measuring point column respectively, and their wind pressure spectra were discussed. Results show that the maximum wind suction is at the location of the low windward point, and the wind pressure gradient changes greatly. The saddle rise-span ratio is mainly embodied in the rear of two-thirds area of the roof of wind pressure, and the severer wind suction occurs with the greater the curvature. The greater the windward side height is with the higher the wind suction. The wind suction has maximum change near the low point of the windward. In high and middle windward point the wind pressure spectrum is the narrowband distribution and low frequency plays a leading role at the front windward, however, the high frequency band energy of back area is greater than that of the front area. The wind is characterized by wide distribution and the high frequency energy increases gradually as the development of flow downstream.