Flow around square-like cylinders with corner and side modifications. Issue 215 (August 2021)

• Record Type: Journal Article
• Authors: Du, Xiaoqing; Shi, Dingjun; Dong, Haotian; Liu, Yantai
• Is Part Of: Journal of wind engineering and industrial aerodynamics. Issue 215(2021)
• Publication Date: 2021-08
• Subjects: Aerodynamic shape modification -- Large-eddy simulation -- Square-like cylinder -- Flow pattern -- Aerodynamic force; Wind-pressure -- Periodicals; Buildings -- Aerodynamics -- Periodicals; Pression du vent -- Périodiques; Constructions -- Aérodynamique -- Périodiques; Buildings -- Aerodynamics; Wind-pressure; Periodicals
• DOI: 10.1016/j.jweia.2021.104686
• Languages: English
• ISSNs: 0167-6105

Abstract

Abstract: Shape modification effectively reduces the wind loading and wind-induced vibrations of slender structures. Large-eddy simulation is used to investigate the flow around multiple square-like cylinders at a Reynolds number of 22, 000. Based on a standard square cylinder, six square-like cylinders are simulated with sharp/rounded corners and straight/concave/convex sides. The combination of rounded corners and convex sides enables the best aerodynamic performance. Furthermore, a parametric study on the round-convex cylinder is conducted considering a fixed corner radius and various side curvatures B / K ( B : nominal side length; K : side radius). The results show that both the aerodynamic characteristics of and the flow features around the cylinder change considerably with varying B / K and that three distinct flow regimes are observed. In Stage I (0 ≤ B / K ≤ 0.71), the flow separates at the front corners, and the aerodynamic forces decrease gradually. In Stage II (0.71 < B / K < 1.00), the shear layer separating at the front corner-side region reattaches to the lateral sides. The fluctuating coefficients rise at B / K = 0.74; thereafter, the aerodynamic forces drop and are minimized at B / K = 1.00. In Stage III (1.00 ≤ B / K ≤ 1.77), flow separates at the lateral sides, and the aerodynamic forces recover gradually. Highlights: Rounded corners and convex sides reduce the aerodynamic forces. Three flow regimes are identified for the round-convex cylinder. The side curvature B / K = 1.00 enables the best aerodynamic performance.