The aerodynamic disturbance caused by the free-ends of a circular cylinder immersed in a uniform flow

Experimental investigation on the aerodynamic loads and wake flow features of a low aspect-ratio circular cylinder

“…The wakes of finite circular cylinders in cross-wind are dominated by the velocity fluctuations induced by the alternate vortex shedding from the body sides, as documented by Farivar (1981), Ayoub and Karamcheti (1982), Fox et al (1993), Bearman (2011), Griffith et al (2011), Suthon and Dalton (2011) and Visscher et al (2011), in which the presence of clear vortex shedding from most of the cylinder span, with frequencies of the same order as those typical of twodimensional flow, was found for models with aspect-ratio h=d 4 10 (where h is the cylinder height and d its diameter). However, a decrease of the frequency was found in a zone approaching the upper end of the cylinders, probably due to an increase in the formation length of the shed vortices.…”

Time-resolved wake dynamics of finite wall-mounted circular cylinders submerged in a turbulent boundary layer

“…Several experimental and numerical studies have been conducted in the past to investigate the wake structure of FWMCs using geometries such as circular cylinders (Sumner, Heseltine & Dansereau 2004;Pattenden, Turnock & Zhang 2005;Krajnović 2011;Tang et al 2016;Heidari et al 2017;Hamed & Peterlein 2020) and cylinders with sharp edges (Balachandar & Tachie 2001;Wang et al 2006;Wang & Zhou 2009;Bourgeois, Sattari & Martinuzzi 2011;Nasif, Balachandar & Barron 2015;Yauwenas et al 2019). While most of the previous studies examined the FWMC in a uniform flow (Farivar 1981;Okamoto & Yagita 1973;Fox, Apelt & West 1993) or thin turbulent boundary layer (TBL) (δ h, where δ is the boundary layer thickness and h is the cylinder height) (Pattenden et al 2005;Wang & Zhou 2009;Krajnović 2011;Yauwenas et al 2019), a FWMC that is fully immersed in a thick TBL (δ > h as illustrated in figure 1) has received less attention, though encountered in many of the aforementioned practical applications. For δ > h, the FWMC encounters stronger mean shear and higher turbulence intensity in the approach flow, which can further complicate the unsteady flow separation and wake dynamics of the cylinder compared to its counterpart in a uniform flow or thin TBL.…”

Effects of free-end corner shape on flow structure around a finite cylinder

“…The study of finite-span bluff bodies located in an atmospheric boundary layer (hereafter, denoted as ABL) is of interest due to its practical importance in civil and wind engineering applications (Uematsu et al, 1990;Fox et al, 1993). The presence of a free end modifies the flow structures in the near-wake region, such as the vortex structure, vortex shedding pattern, turbulent structure and surface pressure distribution.…”