The laminar horseshoe vortex upstream of a short-cylinder confined in a channel formed by a pair of parallel plates

Abstract

A flow visualization experiment was performed in order to characterize the laminar horseshoe vortex system that appears upstream of the junction of a short cylinder and a pair of flat parallel plates. The experiments were performed in a water tunnel and the technique used for flow visualization was laser illumination of seeded particles whose traces were captured using long exposure photography. Geometrical and flow parameters, such as Reynolds number and height-to-diameter ratio of the cylinders, are varied during the experiments and the flow regimes are analyzed as a function of these parameters. The behavior of vortex systems is reported. For low Reynolds number cases, the vortices stay in a fixed position, as the Reynolds number is increased the number of vortices grows and for larger Reynolds numbers the vortex system becomes oscillatory and for further increases it becomes periodic. As for the dimensionless height of the cylinders, the vortex system is weak for short cylinders and increases its strength and number of vortices as the cylinder height-to-diameter ratio is increased. For further increases in height the vortex system do not change, which shows that the flow becomes independent of the height-to-diameter ratio for sufficiently tall cylinders. Information of the frequency of appearance of periodic vortices is also included.

The interaction between cross-sea bridge and the environment

“…The hydrodynamic surroundings between Donghai Bridge and the wind turbine array will start changing because of the relationship between the flow of water well with the pier and windmill base, which will modify a multitude of factors in the aquatic environment. These variations are going to not only impact the concentrations of total suspended solids and chlorophyll in addition to the surface temperature of the sea groundwater of the Donghai Overpass and the waterwheels, but they will additionally potentially trigger the necessary modifications in other freshwater ecosystems [5][6]. Due to both the pier and the windmill base's water-blocking action when water flows past them, the movement and structure of the upstream water are going to change.…”

Effects of an upstream triangular plate on the wing-body junction flow

“…Gregory and Walker (1951), Sedney and Kitchens (1975), and Rodriguez y Dominguez et al (2006) showed that horseshoe vortices are weaker for short cylinders and an increase in height leads to an increase in both the strength and the number of vortices. Once the cylinder is sufficiently tall, the horseshoe vortex system becomes independent of height variations [20,21,22]. Leading edge shape of the obstacle was shown to matter for the size and strength of the horseshoe vortices.…”

Effects of an upstream tetrahedron on the circular cylinder–flat plate juncture flow

“…The characteristics of horseshoe vortex at the junction of the cylinder and the base plate were reviewed by Ballio et al (1998). Seal and Smith (1999a), Akilli and Rockwell (2002), Sumner et al (2004), Pattenden et al (2005), Rodríguez y Domínguez et al (2006), Sahin et al (2007), Sumner and Heseltine (2008), Sahin and Ozturk (2009), Kirkil and Constantinescu (2012), and Huang et al (2014) reported the complex flow phenomena of the horseshoe vortex system around the circular cylinder. Porteous et al (2014) reviewed the previous studies on the flow-induced noise from finite wall-mounted circular and square cylinders and then reported that the flow-induced noise characteristics of the wall-mounted cylinders were influenced by the height of the boundary layer.…”