flow structure and heat transfer characteristics around two-equal in-tandem square cylinders in the two dimensional laminar and turbulent flow regimes are simulated numerically for reynolds and prandtl numbers, re=1-1×10 5 , pr=0.71, respectively. the investigation is based on an implicit finite volume scheme for integrating the unsteady navier-stokes equations and use of standard κ-ε model to ...

the flow characteristics around an elliptic cylinder with an axis ratio of ar=2 located near a flat plate were investigated experimentally. the elliptic cylinder was located on the inside and outside a turbulent boundary layer region whose thickness (δ) is 0.38b. the reynolds numbers based on the height of the cylinder cross-section were 15000 and 30000. measurements of mean velocity and turbul...

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...

The objective of this study is to develop a method of controlling vortex shedding behind a bluff body using control theory. A suboptimal feedback control procedure for local sensing and local actuation is developed and applied to the flow behind a circular cylinder. The location of sensors for feedback is limited to the cylinder surface and the control input from actuators is the blowing and su...

In this paper, we study approximate cloaking for the Helmholtz equation in three dimensions where the cloaking device is based on transformations which blow up a cylinder of fixed height and small cross section of radius ε into the cloaked region. Assuming the zero Dirichlet boundary condition is imposed on the boundary of the cloaked region, we show that the degree of visibility is of order ε ...

Now imagine the elliptical cross section replaced by any curve lying on the surface of a right circular cylinder. What happens to this curve when the cylinder is unwrapped? Consider also the inverse problem, which you can experiment with by yourself: Start with a plane curve (line, circle, parabola, sine curve, etc.) drawn with a felt pen on a rectangular sheet of transparent plastic, and roll ...

Consider the scattering of an electromagnetic time-harmonic plane wave by an infinite cylinder having an open crack Γ and a bounded domain D in R2 as cross section. We assume that the crack Γ is divided into two parts, and one of the two parts is possibly coated on one side by a material with surface impedance λ. Different boundary conditions are given on Γ and ∂D. Applying potential theory, th...

Backscattering enhancement phenomenon in a random medium is studied by numerically analyzing a bistatic radar cross-section of a circular cylinder, under the condition that the spatial coherence length of the incident waves around the cylinder is larger enough than the size of the cylinder. The numerical analysis shows that the phenomenon may occur not only in the backward direction but also in...

The scattering enhancement phenomenon is studied by numerically analyzing a bistatic radar cross-section (RCS) of a circular cylinder in a strong continuous random medium, under the condition that the spatial coherence length of the incident waves around the cylinder is larger enough than the size of the cylinder. The numerical analysis shows such a new result that the scattering is not enhance...

Abstract This paper investigates the effect of fitting fins at corners a square cylinder on aerodynamic characteristics via wind tunnel tests and large eddy simulations (LES). Although it has been recognized that corner have remarkable cylinder, no study carried out to systematically evaluate this reveal underlying mechanism. Three types fin configurations, i.e. fitted only leading corners, tra...