Journal ArticleDOI
The formation and evolution of synthetic jets
Barton L. Smith,Ari Glezer +1 more
Reads0
Chats0
TLDR
In this article, a nominally plane turbulent jet is synthesized by the interactions of a train of counter-rotating vortex pairs that are formed at the edge of an orifice by the time-periodic motion of a flexible diaphragm in a sealed cavity.Abstract:
A nominally plane turbulent jet is synthesized by the interactions of a train of counter-rotating vortex pairs that are formed at the edge of an orifice by the time-periodic motion of a flexible diaphragm in a sealed cavity. Even though the jet is formed without net mass injection, the hydrodynamic impulse of the ejected fluid and thus the momentum of the ensuing jet are nonzero. Successive vortex pairs are not subjected to pairing or other subharmonic interactions. Each vortex of the pair develops a spanwise instability and ultimately undergoes transition to turbulence, slows down, loses its coherence and becomes indistinguishable from the mean jet flow. The trajectories of vortex pairs at a given formation frequency scale with the length of the ejected fluid slug regardless of the magnitude of the formation impulse and, near the jet exit plane, their celerity decreases monotonically with streamwise distance while the local mean velocity of the ensuing jet increases. In the far field, the synthetic jet i...read more
Citations
More filters
Journal ArticleDOI
Three-Dimensional Computation of a Synthetic Jet in Quiescent Air
Jing Cui,Ramesh K. Agarwal +1 more
TL;DR: In this article, an unsteady Reynolds-averaged Navier-Stokes solver, WIND, is employed to capture the flowfield features of a synthetic jet pulsing into the quiescent air, case 1 of NASA Langley Research Center Workshop: "CFD validation of synthetic jets and turbulent separation control," held at Williamsburg, Virginia in March 2004.
Journal ArticleDOI
Active Flow Control for High Speed Jets with Large Window PIV
Zachary Berger,Patrick R. Shea,Matthew G. Berry,Bernd R. Noack,Sivaram Gogineni,Mark Glauser +5 more
TL;DR: In this paper, a Mach 06 jet flow field with particle image velocimetry (PIV) and simultaneously sampled near and far-field pressure was investigated and it was found that active flow control changes the potential core length and shear layer expansion, which affects the overall sound pressure levels in the far field.
Proceedings ArticleDOI
Synthetic jets in cross -flow. part i: round jet
Khairul Q. Zaman,Ivana Milanovic +1 more
TL;DR: In this article, an experimental investigation on synthetic jets fro m round orifices with and without cross-flow is presented, and the threshold of stroke length for synthetic jet formation, in the abse nce of the cross -flow, is found to be L 0 /D � 0.5.
Journal ArticleDOI
Interaction of synthetic jets with a fully developed turbulent channel flow
Gaetano Iuso,G. M. Di Cicca +1 more
TL;DR: In this paper, the effects of the interaction of a spanwise array of inclined circular synthetic jets with a turbulent channel flow have been experimentally studied, where the array is arranged in a convergent couple configuration, where each single jet is oriented at ± 45° in the plane perpendicular to the mean channel flow.
Journal ArticleDOI
Active manipulation of a particle-laden jet
David Tamburello,Michael Amitay +1 more
TL;DR: In this article, a reduction technique was used to calculate 3D flow fields from multiple 2D measurement planes to study the complex 3D interactions between a particle-laden jet and a single synthetic jet or a continuous control jet.
References
More filters
Journal ArticleDOI
An Album of Fluid Motion
Milton van Dyke,Frank M. White +1 more
TL;DR: In this paper, the authors present a visualisation de l'ecoulement for tourbillon and dynamique des: fluides, aubes, cylindre, instabilite.
Journal ArticleDOI
Streamwise vortex structure in plane mixing layers
Luis P. Bernal,Anatol Roshko +1 more
TL;DR: In this paper, it is shown that superimposed on the primary, spanwise vortex structure there is a secondary, steam wise vortex structure, and the spatial organization of the secondary structure produces a well-defined spanwise entrainment pattern in which fluid from each stream is preferentially entrained at different spanwise locations.
Journal ArticleDOI
The planar turbulent jet
Ephraim Gutmark,Israel Wygnanski +1 more
TL;DR: In this article, hot-wire measurements in a plane incompressible jet are reported, where the flow was found to be self-preserving beyond x/d > 40 and measurements were made up to x/D = 120.
Journal ArticleDOI
The structure of a self-preserving turbulent plane jet
TL;DR: The structure of a self-preserving turbulent plane jet exhausting into a slow-moving parallel airstream is studied in this paper, where results of turbulence measurements and the structure is compared with that of the plane wake.
Journal ArticleDOI
Preferred modes and the spreading rates of jets
Ephraim Gutmark,Chih-Ming Ho +1 more
TL;DR: In this article, it is suggested that extremely low-level spatially coherent disturbances in individual facilities change the initial conditions of a laminar shear layer and result in the discrepancies reported in the literature.