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Showing 1 to 11 of 11 for “"Karman vortex street"”.
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Investigation of a space-time adaptive method for bluff body flows
… able to capture ow unsteadiness, shown as a von Karman vortex street formed behind the cylinders. The adapted results are compared with time-marching solutions to determine the eciency and reliability of this method.
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Development of a data reduction method for a high frequency angle probe
… The first experiment tested the angle probe in a Karman vortex street shed from a cylinder. In the second experiment, the angle probe was placed in an open air jet with an exit Mach number of 0.42. Plots of the time-resolved measurements and the Fast Fourier Transform analysis were made for each …
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Extracting energy from unsteady flows through vortex control
Vortex control is a new paradigm in fluid mechanics, with applications to propulsion and wake reduction. A heaving and pitching hydrofoil placed in a flow with an array of oncoming vortices can achieve a very high propulsive efficiency and reduced wake signature. The canonical example of flow with …
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Active feedback control of a wake flow via forced oscillations based on a reduced model
… the bubble becomes unstable and develops into a Karman vortex street of alternating vortices. This instability is responsible for the occurrence of large amplitude oscillations in the lift and an increase in the mean drag. It was previously shown by numerical simulation that the mechanism driving …
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Investigation of the effect of a circular patch of vegetation on turbulence generation and sediment deposition using four case studies
… are formed downstream of the patch in a von-Karman vortex street that meets at the center of the flow a distance, Lw, downstream of the patch. For the flexible submerged cases, streamlines reattach to the bed of the flume a distance, Lv, downstream of the patch. In addition, for the flexible …
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Investigation of the effect of a circular patch of vegetation on turbulence generation and sediment deposition using four case studies
… are formed downstream of the patch in a von-Karman vortex street that meets at the center of the flow a distance, Lw, downstream of the patch. For the flexible submerged cases, streamlines reattach to the bed of the flume a distance, Lv, downstream of the patch. In addition, for the flexible …
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Analysis, finite element approximation, and computation of optimal and feedback flow control problems
… The uncontrolled flow exhibits an unsymmetric Karman vortex street and a periodic lift coefficient. The size of the oscillations in the lift is reduced through an active feedback control system. The control used is the injection and suction of fluid through orifices on the cylinder; the amount …
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The Testing and Verification of a Nanomembrane Based Pressure Sensor for Small-Scale Underwater Pressure Measurements
… as a result of eddies which are evident in a Von Karman vortex street and a turbulent flow. Despite the presence of EMI noise within a water tunnel, the sensors demonstrated a decay of pressure fluctuations that is consistent with previous research in the field. Overall, the present work increases …
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Modification of Blade-Vortex Interactions Using Leading Edge Blowing
… blowing (LEB) flow control for modifying the vortex induced vibrations on an airfoil in the wake of a circular cylinder. The airfoil was allowed to oscillate perpendicular to the fluid flow direction in response to the impinging Von-Karman vortex street. The flow field and airfoil vibrations …
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Interactions among flow, sediment deposition and aquatic vegetation in a channel
… a solid obstruction, the formation of a von-Karman vortex street behind a porous obstruction is delayed until the end of the steady wake region. As the stem density decreases (i.e. the patch becomes sparser), the velocity deficit in the steady wake region decreases and the length of the …
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Numerical modeling and simulation of cavitating flows in different regimes
… investigate the effects of water quality on tip vortex inception. A numerical method based on the homogeneous mixture model, fully compressible formulation and finite rate mass transfer developed by Gnanaskandan and Mahesh [1] is extended to include the effects of non–condensable gas (NCG). We …