LES for Turbulent Flows through Ducts of Regular-Polygon Cross-Sections

• 作者: Masayoshi Okamoto
• 来源期刊: 机械工程与自动化:英文版
• 学科: 物理学
• 关键词: TURBULENCE secondary flow regular polygonal duct LES IB method
• 年，卷（期）: 2020,（5）
• 页码范围: 140-154
• 页数: 15页
• 分类号: O35

摘要

In this study,a large eddy simulation(LES)for fully-developed turbulent flows through a duct of regular-polygon cross-section using the immersed boundary(IB)method is performed.In case of the turbulent flow through the square duct,though there are some disagreements of the mean quantities related with the streamwise velocity among the present LES,the previous direct numerical simulation(DNS)and the LES without the IB method,and the present LES can reproduce the secondary flow of the DNS and LES.The LES result for ten types of regular-polygon duct shows that the secondary-flow speed decreases as the number of sides of the regular polygon n increases and that the secondary flow in case of the regular icosagon duct disappears like the turbulent pipe flow.In case of low n,the behavior of the turbulent structures near the side center is different from that near the vertex.