首先介绍建筑特征湍流的含义及其表现的几种形式。然后重点对一种典型的特征湍流形式——锥形涡进行了探讨,给出了通过风压信息识别其特征参数的方法。最后,结合一大跨度平屋盖缩尺模型风洞测压试验,对锥形涡的涡心位置、作用范围以及运动模式等特征参数进行研究,并给出了定量结果。这些工作有助于更好地总结屋面风压分布的一些共性规律,并进一步提出符合屋面绕流特点的阵风荷载模型或脉动风压功率谱。
This paper presents the definition of signature turbulence and some representations, especially introducing one typical kind of building generated turbulence, conical vortices on fiat roofs. The characteristics of conical vortices areinvestigated by wind tunnel test, some character parameters are identified through contour maps of roof surface wind pressure coefficient, including the position of the maximum mean suction for the axis of the conical vortex and the position of the maximum r. m.s. pressure coefficient for the width of the conical vortex. The movement of conical vortex is also investigated by studying the changes of wind pressure on some crosswind and longitudinal section. Finally the vortices regions marked are useful for establishing a reasonable gust wind model or a general power spectra of wind pressures.