椭圆形钢管混凝土构件性能的研究Ⅲ:流体作用下阻力系数

Study on Behavior of Elliptical Concrete Filled Steel Tube Members Ⅲ:Drag Coefficient under Fluid Action

椭圆形截面可以比圆形、方形和多边形截面更有效地折减流体对椭圆形钢管混凝土所作用的荷载。例如,采用椭圆形钢管混凝土桥墩,相比圆钢管混凝土和矩形钢管混凝土,可以很有效地折减水流对桥墩的冲击作用。本文采用数值模拟的方法,通过CFD软件建立椭圆形截面的绕流数值模型,分别研究了不同形状的椭圆形截面在不同流速的空气和水中阻力系数随雷诺数变化的情况,得出相同雷诺数下阻力系数随截面形状的变化规律以及同一种形状截面阻力系数随雷诺数的变化规律,最后给出了阻力系数与雷诺数、截面形状之间的关系式和风载计算公式。

Compared with the cross-section shape of circle,square,polygon,elliptical section can be more effective in reduction of the load that the fluid acts on it. For example,the piers using elliptical concrete filled steel tube （CFST）,can more effectively reduce the impact acting on the piers,compared with piers using circular or rectangular CFST. In this paper,using the method of numerical simulation,numerical simulation models of elliptical CFST flow around are established by CFD software,the relationship that drag coefficient varies with Reynolds numbers of elliptical section of different cross-section in air and water with different velocities is investigated,and the regularity between drag coefficient and cross-section under fixed Reynolds number,between drag coefficient and Reynolds numbers of fixed cross-section is obtained. Through it,the relationship of drag coefficient,and shape of the section is obtained. Finally,the calculating formula of wind or water load on the member is given.