Journal ArticleDOI
The evolution of round zero-net-mass-flux jets
John Cater,Julio Soria +1 more
TLDR
In this article, the structure and mean flow quantities of round zero-net-mass-flux (ZNMF) jets are determined by a piston oscillating in a cavity behind a circular orifice.Abstract:
This paper reports on an experimental investigation to determine the structure and mean flow quantities of round zero-net-mass-flux (ZNMF) jets. These jets are generated by a piston oscillating in a cavity behind a circular orifice. Several different flow patterns were observed with dye flow visualization and a parameter map of these was generated. Cross-correlation digital particle image velocimetry was used to measure instantaneous two-dimensional in-plane velocity fields in a plane containing the orifice axis. These velocity fields are used to investigate the existence of a self-preserving velocity profile in the far field of the ZNMF jet. The mean flow quantities and turbulent statistics of the ZNMF jets were compared with measurements for ‘equivalent’ continuous jets in the same apparatus. Phase-averaged velocity measurements were obtained in the near field of the ZNMF jets and were used to determine the radial entrainment. The out-of-plane vorticity fields were also investigated to gain an understanding of the mechanisms responsible for the difference in spreading rate of ZNMF jets compared to conventional continuous jets. A conceptual model of the ZNMF jet structure in the near field for Strouhal numbers much less than one is proposed that explains the observed behaviour of these ZNMF jets.read more
Citations
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Journal ArticleDOI
Actuators for Active Flow Control
Louis N. Cattafesta,Mark Sheplak +1 more
TL;DR: This review provides a framework for the discussion of actuator specifications, characteristics, selection, design, and classification for aeronautical applications and attempts to highlight the strengths and inevitable drawbacks of each and highlight potential future research directions.
Journal ArticleDOI
Closed-Loop Turbulence Control: Progress and Challenges
Steven L. Brunton,Bernd R. Noack +1 more
Journal ArticleDOI
Experimental investigation on interactions among fluid and rod-like particles in a turbulent pipe jet by means of particle image velocimetry
TL;DR: In this paper, the near field of a turbulent circular pipe jet laden with rigid rod-like particles is investigated experimentally by means of particle image velocimetry and two mass fraction loadings are examined at a Reynolds number equal to 9,000.
Journal ArticleDOI
Experimental study of the formation and scaling of a round synthetic jet
TL;DR: In this article, the flow field from a piston-cylinder synthetic jet actuator was investigated in detail over a range of dimensionless stroke values, L∘∕D∘, and Reynolds numbers, ReU∘.
Journal ArticleDOI
Frequency response of a synthetic jet cavity
TL;DR: In this paper, the effect of excitation frequency on the synthetic jet flow is studied for cavities of different depths and for orifices of different diameters, and the results are expected to be useful for designing synthetic jet cavity.
References
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Book
A First Course in Turbulence
Henk Tennekes,John L. Lumley +1 more
TL;DR: In this paper, the authors present a reference record created on 2005-11-18, modified on 2016-08-08 and used for the analysis of turbulence and transport in the context of energie.
Journal ArticleDOI
Turbulent gravitational convection from maintained and instantaneous sources
TL;DR: In this article, the authors developed a theory of convection from maintained and instantaneous sources of buoyancy, using methods which are applicable to stratified body fluids with any variation of density with height; detailed solutions have been presented for the case of a stably stratified fluid with a linear density gradient.
Journal ArticleDOI
Some measurements in the self preserving jet
Israel Wygnanski,H. E. Fiedler +1 more
TL;DR: In this paper, the axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers and the quantities measured include mean velocity, turbulence stresses, intermittency, skewness and flatness factors, correlations, scales, low-frequency spectra and convection velocity.
Journal ArticleDOI
The formation and evolution of synthetic jets
Barton L. Smith,Ari Glezer +1 more
TL;DR: 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.
Journal ArticleDOI
Velocity measurements in a high-Reynolds-number, momentum-conserving, axisymmetric, turbulent jet
TL;DR: In this article, the turbulent flow resulting from a top-hat jet exhausting into a large room was investigated and the Reynolds number based on exit conditions was approximately 105 Velocity moments to third order were obtained using flying and stationary hot-wire and burstmode laser-Doppler anemometry (LDA) techniques.