Journal ArticleDOI
Vortex evolution in a round jet
H. A. Becker,T. A. Massaro +1 more
TLDR
In this article, a study has been made of the varicose instability of an axisymmetrical jet with a velocity distribution radially uniform at the nozzle mouth except for a laminar boundary layer at the wall.Abstract:
A study has been made of the varicose instability of an axisymmetrical jet with a velocity distribution radially uniform at the nozzle mouth except for a laminar boundary layer at the wall. The evolutionary phenomena of instability, such as the rolling up of the cylindrical vortex layer into ring vortices, the coalescence of ring vortex pairs, and the eventual disintegration into turbulent eddies, have been investigated as a function of the Reynolds number using smoke photography, stroboscopic observation, and the light-scatter technique.Emphasis has been placed on the wavelength with maximum growth rate. The jet is highly sensitive to sound and the effects of several types of acoustic excitation, including pure tones, have been determined.read more
Citations
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Journal ArticleDOI
Orderly Structure in Jet Turbulence
S. C. Crow,F. H. Champagne +1 more
TL;DR: In this paper, the authors show that a large-scale orderly pattern may exist in the noiseproducing region of a round subsonic jet by observing the evolution of orderly flow with advancing Reynolds number.
Book ChapterDOI
Particle Image Velocimetry
TL;DR: In this paper, the authors use hot-wire (HW) or laser velocimetry (LV) to estimate the velocity, vorticity, and pressure fields of wake flows.
Journal ArticleDOI
Vortex pairing : the mechanism of turbulent mixing-layer growth at moderate Reynolds number
C. D. Winant,F. K. Browand +1 more
TL;DR: A mixing layer is formed by bringing two streams of water, moving at different velocities, together in a lucite-walled channel as mentioned in this paper, where dye is injected between the two streams just before they are brought together, marking the vorticitycarrying fluid.
Journal ArticleDOI
Vortical structure in the wake of a transverse jet
T. F. Fric,Anatol Roshko +1 more
TL;DR: In this article, structural features resulting from the interaction of a turbulent jet issuing transversely into a uniform stream are described with the help of flow visualization and hot-wire anemometry.
Journal ArticleDOI
Elliptic jets. I - Characteristics of unexcited and excited jets
Fazle Hussain,Hyder S. Husain +1 more
TL;DR: Experimental studies of incompressible elliptic jets of different aspect ratios and initial conditions are summarized along with the effects of excitations at selected frequencies and amplitudes in this paper, where the experimental facilities and procedures are described and jet spread and decay are discussed.
References
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Journal ArticleDOI
On the inviscid instability of the hyperbolictangent velocity profile
TL;DR: In this paper, the Rayleigh stability equation of inviscid linearized stability theory was integrated numerically for amplified disturbances of the hyperbolic-tangent velocity profile.
Journal ArticleDOI
Analysis of the stability of axisymmetric jets
G. K. Batchelor,A. E. Gill +1 more
TL;DR: In this article, the authors studied the stability of steady axisymmetric parallel flows of uniform fluid in the absence of rigid boundaries, and they focused on the stability characteristics in the limit of large Reynolds number and determined the (integral) value of n at which the growth rate is a maximum in these simpler circumstances.
Journal ArticleDOI
The stability and transition of a two-dimensional jet
TL;DR: In this article, the response characteristics of laminar jets to artificial external excitation were investigated in detail by using sound as an exciting agent, where the frequency of excitation coincides with that of self-excited sinusoidal fluctuations.
Journal ArticleDOI
Flow through Pipe Orifices at Low Reynolds Numbers
TL;DR: In this paper, it was shown that for a particular diameter ratio (i.e., orifice diameter ÷ diameter of pipe line) discharge coefficient is nearly constant under conditions of turbulent flow, however, very appreciable variations occur in the value of discharge coefficient, suggesting that the accompanying variations in the nature of the flow through and beyond the orifice will be no less marked.
Journal ArticleDOI
On the light-scatter technique for the study of turbulence and mixing
TL;DR: The light-scatter technique facilitates study of the concentration field when one of the streams entering a mixing region is marked with colloidal particles as mentioned in this paper, and the system response is analyzed theoretically.
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