the interaction between wakes of bluff body and airfoil has profound influences on system performance in many industrial applications, e.g., turbo-machinery and cooling fan. the present work investigates the effect of configuration including airfoil’s angle of attack and transverse spacing of the models on frequency behavior of the cylinder’s near-wake. the experiments were carried out under su...

We present an effective technique for suppressing the vortex-induced vibrations of bluff bodies by eliminating the von Kármán street formed in their wake. Specifically, we find that small amounts of combined windward suction and leeward blowing around the body modify the wake instability and lead to suppression of the fluctuating lift force. Three-dimensional simulations and stability analysis ...

Vortex shedding from a circular cylinder and from an inclined flat plate is computed with a finite volume CFD code with RNG k-ε turbulence model. The wake behind the circular cylinder consists of two trains of vortices of equal strengths. Dependence of vortex patterns on Reynolds numbers at Re between 10 and 10 is investigated. Flow over the inclined flat plate is asymmetric and unequal charact...

Vortex interactions in helicopter rotor wakes are visualized using enhanced flow visualization techniques, which in turn play a crucial role in understanding the dynamics of these complex flows. Iso-surfaces are clipped in a 3D volume to reduce visual clutter. Flow textures are improved to highlight vortical flow structure and vortex-wake interactions. These visualization techniques are applied...

Dynamics of a point vortex in interaction with a broad profile of background vorticity is studied experimentally by using an electron plasma. The observed motion of the vortex compares favorably with a recently proposed theoretical model [D. A. Schecter and D. H. E. Dubin, Phys. Rev. Lett. 83, 2191 (1999)]. Perturbations in the background distribution in the wake of the spiral orbit of the vort...

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Results from a wind tunnel test of two delta wings in close proximity are presented and compared with predictions from a vortex lattice method. The wake effects on lift are slightly overpredicted when the aircraft overlap in the spanwise direction. The wake induced effects on pitching and rolling moment are well predicted. A maximum induced drag reduction of 25% is measured on the trail aircraf...

This Letter introduces a control strategy for taming the wake turbulence behind a cylinder. An angular momentum injection scheme is proposed to synchronize the vertical velocity field. We show that the base suction, wake formation length, absolute instability, and the Kármán vortex street are effectively controlled by the angular momentum injection. A control equation is designed to implement t...

Bio-inspired aerodynamic designs have been mutually promoted by the studies on flapping wings in the past decades. Among the tons of researches topics, the wake formation/structure of an oscillating airfoil is more attractive, and it results in the development of both numerical methods and flow diagnostics techniques. In this paper, wake formation behind a sinusoidally piching NACA 0012 has bee...

Research on the lateral line of fish has mainly focused on the detection of oscillating objects. Yet many fish are able to track vortex wakes that arise from other fish. It is not yet known what the sensory input from a wake looks like and how fish can extract relevant information from it. We present a mathematical model to determine how vortices stimulate the canal lateral line and verify it b...