Descripción
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We propose to study the stability properties of a wake air flow forced by electrohydrodynamic (EHD) actuators, dielectric barrier discharge (DBD) type. EHD actuators can add momentum to the ow around an object in regions close to the wall. As the forcing frequencies, characteristic of DBD, are much higher than the natural shedding frequency of the flow (kHz vs. Hz), we consider in this work the forcing actuation as stationary. The actuators are disposed symmetrically near the boundary layer separation point. We study the ow around a cylinder modi?ed by EHD actuators experimentally by means of particle image velocimetry (PIV) measures and also computationally by solving the generalized eigenvalue problem obtained from linearized Navier-Stokes equations. In the numerical part, the presence of the EHD actuators has been implemented as a boundary condition on the cylinder surface. The base flow obtained computationally using this boundary condition has been compared with the experimental one in order to match the control parameters from both methodologies. Once the base flow agreement has been veri?ed, the Hopf bifurcation produced when the flow starts the vortex shedding has been studied by di?erent methods: ?rst, when the base flow is obtained from experimental snapshots, the evolution of the amplitude velocity oscillations is monitored; second, when the base flow is computationally obtained, a global linearized eigenvalue problem is solved for the instability study. Finally, the critical parameters have been compared. | |
Internacional
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Si |
Nombre congreso
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6th Theoretical Fluid Mechanics Conference. |
Tipo de participación
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960 |
Lugar del congreso
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Honolulu, HI, EEUU |
Revisores
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Si |
ISBN o ISSN
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978-1-61839-172-8 |
DOI
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Fecha inicio congreso
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27/06/2011 |
Fecha fin congreso
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30/06/2011 |
Desde la página
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1 |
Hasta la página
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18 |
Título de las actas
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The scenario of two-dimensional instabilities of the cylinder wake under EHD forcing: A linear stability analysis |