A narrow strip has been introduced as a control element to suppress vortex shedding from a cylinder. The strip is set parallel to the cylinder axis, and the key parameter of control in this study is the strip position, which is determined by the angle of attack of the strip and the distance between the strip and the cylinder axis. A circular cylinder and a square cylinder were tested respective...

In this paper, 3D flow past a long tapered tower is examined. A tapered tower is described by the taper ratio. Tapered cylinders are a good description of many structures, like wind turbine tower e.t.c. Similar to the flow around cylinders, the Reynolds number is the important flow parameter, and the Strouhal number represents the shedding frequency. These flow patterns are difficult to predict...

The Bénard-von Karman vortex shedding instability in the wake of a cylinder is perhaps the best known example of a supercritical Hopf bifurcation in fluid dynamics. However, a simplified physical description that accurately accounts for the saturation amplitude of the instability is still missing. Here we present a simple self-consistent model that provides a clear description of the saturation...

The current investigation examines periodic vortex shedding from surface mounted pyramids with taper ratios (2*height/base diameter) of 7.6 to 14.3 in a thin boundary layer using surface pressure measurements along the obstacle faces. Over the lower portion of the pyramids (y/h<~0.5) regular periodic vortex shedding was observed. Near the tip, a large time-scale structure was observed. This str...

To understand the physics of the complex vortex flow field of the F/A-18 aircraft during maneuvering at high incidences, a series of flow visualizations were conducted in the IAR 0.38 x 0.51m water tunnel. A 1/72-scale model was tested on the new orbital-platform rotary apparatus at angles of attack from 20o to 65o with sideslip angles in the range 10 . It was found that the aerodynamic behavio...

By using a Wiener-Hopf approach, an analytical description is derived of the scattered field of a harmonic sound wave coming out of an open ended annular duct (a semi-infinite cylinder inside of which, coaxially, is a doubly infinite hub), submerged in a subsonic, coaxial, uniform mean flow. The possibility of vortex shedding from the pipe exit edge is included. Explicit expressions are given f...

The cavitation characteristics were experimentally investigated about long circular-cylindrical orifices of various throat lengths including the orifice with a trip wire. Especially, the shedding process of separated vortex cavity was examined in detail with the observation using high-speed photography. The cavitation impact was measured with an accelerometer. As a result, it is found that the ...

The sea surface imprints of Atmospheric Vortex Street (AVS) off Aleutian Volcanic Islands, Alaska were observed in two RADARSAT-1 Synthetic Aperture Radar (SAR) images separated by about 11 hours. In both images, three pairs of distinctive vortices shedding in the lee side of two volcanic mountains can be clearly seen. The length and width of the vortex street are about 60-70 km and 20 km, resp...