Y. Yokoi and K. Kamemoto, “Initial Stage of a Three-Dimensional Vortex Structure Existing in a Two-Dimensional Boundary Layer Separation Flow: Observation of Laminar Boundary Layer Separation over a Circular Cylinder by Flow Visualization,” JSME International Journal. Ser. 2, Fluids Engineering, Heat Transfer, Power, Combustion, Thermophysical Properties, Vol. 35-II, No. 2, 1992, pp. 189-195.

has been cited by the following article:

• TITLE: Near Wake of a Horizontal Circular Cylinder in Stably Stratified Flows

  AUTHORS: Yuji Ohya, Takanori Uchida, Tomoyuki Nagai

  KEYWORDS: Stratified Flow; Circular Cylinder; Wake Pattern; Vortex Shedding; Lee Wave

  JOURNAL NAME: Open Journal of Fluid Dynamics, Vol.3 No.4, December 4, 2013

  ABSTRACT: The near wake of a circular cylinder in linearly stratified flows of finite depth was experimentally investigated by means of flow visualization and measurements of vortex shedding frequencies, at Reynolds numbers 3.5 × 103-1.2 × 104 and stratification parameters kd 0-2.0. The non-dimensional parameter kd is defined as kd = Nd/U, where N is the Brunt-Vaisala frequency, d, the diameter of the cylinder, and U, the approaching flow velocity. The study demonstrates that as kd increases from zero, the vortex shedding from a circular cylinder progressively strengthens, while the Strouhal number gradually becomes lower than that for homogeneous flow. This phenomenon can be explained by the effect of the increasingly stable stratification which enhances the two-dimensionality of the near-wake flow of the circular cylinder; the enhanced two-dimensionality of the flow strengthens the roll-up of the separated shear layer. Above a certain value of kd, however, vortex formation and shedding are strongly suppressed and the Strouhal number rises sharply. This observation is attributable to the development of stationary lee waves downstream of the circular cylinder because the lee waves strongly suppress vertical fluid motions.