不同攻角下2:1矩形截面棱柱绕流的大涡模拟研究

Large Eddy Simulation of Flow around a 2:1 Rectangular Prism for Various Attack Angles

本文研究了高雷诺数下(Re=24000),宽高比为2:1的矩形截面棱柱在不同风攻角下的绕流问题.基于大涡模拟理论和Smagorinsky亚格子应力模型,运用开源CFD软件OpenFOAM对Navier-Stokes控制方程进行求解,对均匀来流作用下的矩形截面棱柱绕流问题进行了三维数值模拟.通过对平均分量、脉动分量的比较,验证了数值模拟结果的准确性与可靠性,并给出了阻力系数、升力系数、斯特罗哈数随攻角的变化规律以及平均流场和湍流流场的流场特征.基于本文研究结果,通过开源CFD可视化软件ParaView给出了不同攻角下的流型变化,结合平均压力系数的分布,详细解释了不同流型的特征,这些结果验证了基于风洞实验所提出的假设流型,相关结论可为结构风工程设计提供参考依据.本文所采用的软件均为开源软件,其开源特性具有良好的科研价值.

Flow around a 2:1 rectangular section prism for various attack angles has been studied under high Reynolds number(Re=24000).Based on the large eddy simulation(LES)theory and Smagorinsky sub-grid model,the Navier-Stokes equations are solved by using the open source CFD software OpenFOAM,and the flow around the rectangular prism under the uniform flow is numerically simulated.The statistical characteristics are compared with the existing results to confirm the validity of the numerical results.The variation of the drag coefficient,lift coefficient,Strouhal number with the angle of attack,and the characteristics of both the mean flow field and the turbulent flow field are given.According to the simulation results,the flow pattern at different attack angles are given using the open source CFD visualization software ParaView.Combined with the mean pressure coefficients,the features of each flow pattern are explained in detail.Comparing the flow patterns given by LES with the wind tunnel experiments,the assumed flow patterns based on the wind tunnel experiments are verified,and the relevant conclusions can provide reference for the wind engineering structural design.The software used in this paper is open source software,whose open source feature has good scientific research value.