Unsteady free surface wave-induced separation: Vortical structures and instabilities

Shock wave–boundary layer interactions in rectangular inlets: three-dimensional separation topology and critical points

“…The owl-face has been observed when a cylindrical post is mounted perpendicular to a wall (Akilli & Rockwell 2002;Palau-Salvador et al 2010), on the downstream side of a missile-shaped body at an angle of attack (Perry & Chong 1987) and on an aircraft wing (Kandasamy, Xing & Stern 2009). The leading edge of the owl-face in figure 4(a) is similar to the pattern in figure 3(a) in that it contains a saddle point (S) and the upstream streamlines diverge.…”

The effect of air–water interface on the vortex shedding from a vertical circular cylinder

“…16 shows the separation pattern of the mean flow. The separated shear layer was visualized approximately using the isosurfaces of the stagnation C p near the interface immediately before the separation, assuming that the flow outside the separation region is inviscid (Kandasamy et al, 2009). Inside the separated region, the mean vortex core lines are extracted using the vortex core identification technique (Sujudi and Haimes, 1995).…”

“…Its far-wake velocity magnitude is also remarkably smaller than the deep flow region. In addition, the small positive streamwise centerline velocity zone is observed to exist immediately downstream of the cylinder (see the top-left close-up view of the interface centerline velocity), which means a complicated interface topology with the presence of nodal and saddle points (Kandasamy et al, 2009). The mean streamwise velocities in the wake for several vertical locations and the interface are compared in Fig.…”

Towed underwater PIV measurement for free-surface effects on turbulent wake of a surface-piercing body

“…Metcalf et al (2006) investigated boundary layer separation around NACA 0024 foil in various Froude numbers by measuring the surface pressure on the model and free surface elevation, and suggested the unsteady PIV measurement as future work. Based on the measured data, Xing et al (2007) and Kandasamy et al (2009) validated their computational fluid dynamics (CFD) codes. The flow around circular cylinders, as well as hydrofoils, is another major concern in surface piercing object problems since it contains unsteady vortex shedding.…”