建筑结构非定常绕流风场的数值模拟方法

Unsteady numerical simulation method for wind field around building structure

给出了一种适用于计算建筑结构非定常绕流风场的大涡数值模拟算法.该算法基于有限差分法,采用曲线坐标结构网格,能精确描述形状复杂的物面边界,为下一步准确模拟含有因结构受风变形所致运动边界的绕流场奠定了基础.该算法采用投影法解耦纳维-斯托克斯方程中的压力和速度,对非定常流场的时间步进采用二阶Adams-Bashforth方法.采用同位网格以减少计算所需内存,为了平抑同位网格下中心差分格式导致的固有压力波动现象,计算对流速度时采用Rhie-Chow动量插值方法,利用编制的曲线坐标系下大涡模拟数值计算程序,对德州理工大学(TTU)建筑足尺模型绕流风场进行了模拟,所得结果与现场实测和风洞试验结果进行了比较.结果表明,本文算法是建筑结构非定常绕流风场数值模拟的有效方法.

A large eddy simulation algorithm for numerically calculating unsteady wind field around large span structure was given. In this algorithm, a curvilinear coordinate system was used to formulate the numerical model, so the complex wind-structure interface could be described precisely. A projection method was used to split the velocity-pressure linkage in Navier-Stockes （NS） equation. An explicit Adarns-Bashforth differencing scheme was applied for time marching. Governing equations were discredited by central differencing schemes with co-located structured grids to reduce computer memory. The convection velocity was interpolated by using Rhie-Chow method in order to avoid the inherent odd-even decoupling problem. A corresponding computer code was developed and was validated by performing on simulation of wind field around full-scale Texas Tech University （TTU） building model. Furthermore, the simulation results were compared with corresponding field measure data and windtunnel experiment results reported by other authors. The comparison showed that this algorithm is feasible for numerical simulation of unsteady wind field around buildings.