Journal ArticleDOI
Experiments on the flow and acoustic properties of a moderate-Reynolds-number supersonic jet
TLDR
In this article, the authors studied the flow and acoustic properties of a jet at Reynolds number of 70,000 at Mach 2.1 with pitot tubes and hot-wire anemometry.Abstract:
Flow and acoustic properties of a jet at Reynolds number of 70,000 were studied at Mach 2.1. Measurements in a free jet test facility were made with pitot tubes and hot-wire anemometry. Center-line Mach number distributions for natural and excited jets were obtained. A slow initial growth rate was in the potential core region of the jet, indicating a transition from laminar to turbulent flow in moderate Reynolds number jets. The transition occurred within the first 2-3 diameters. Spectral components were calculated for the fluctuating flowfield, and sound pressure levels were measured for the overall near-field noise. The centroid of noise was located about 8 nozzle diameters downstream. The growth rates of instabilities were determined to be in agreement with linear stability theory predictions over a broad frequency range.read more
Citations
More filters
Journal ArticleDOI
Computational aeroacoustics: progress on nonlinear problems of sound generation
Tim Colonius,Sanjiva K. Lele +1 more
TL;DR: A hierarchy of computational approaches that range from semi-empirical schemes that estimate the noise sources using mean-flow and turbulence statistics, to high-fidelity unsteady flow simulations that resolve the sound generation process by direct application of the fundamental conservation principles is discussed in this paper.
Journal ArticleDOI
Noise Investigation of a High Subsonic, Moderate Reynolds Number Jet Using a Compressible Large Eddy Simulation
TL;DR: In this article, the authors investigated the noise radiated by a subsonic circular jet with a Mach number of 0.9 and a Reynolds number of 65000 computed by a compressible Large Eddy Simulation (LES) and demonstrated the feasibility of using LES to predict accurately both the flow field and sound radiation on a domain including the acoustic field.
Journal ArticleDOI
Sound generated by instability waves of supersonic flows. Part 2. Axisymmetric jets
TL;DR: In this paper, a solution describing the spatial evolution of small-amplitude instability waves and their associated sound field of axisymmetric supersonic jets is found using the method of matched asymptotic expansions (see Part 1, Tam & Burton 1984).
Journal ArticleDOI
Active control of high-speed and high-Reynolds-number jets using plasma actuators
TL;DR: In this paper, an axisymmetric Mach 1.3 ideally expanded jet of 2.54 cm exit diameter and a Reynolds number based on the nozzle exit diameter of about 1.1×106.
Journal ArticleDOI
Proposed relationship between broadband shock associated noise and screech tones
TL;DR: In this paper, the relationship between broadband shock associated noise and screech tones is examined and it is shown that from the spectral characteristics point of view, the screech tone may be regarded as a special case of broadband wave associated noise.
References
More filters
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.
Journal ArticleDOI
The role of shear-layer instability waves in jet exhaust noise
TL;DR: In this article, large-scale structures in the form of instability waves are shown to be present in an acoustically and aerodynamically well behaved jet even at high Mach numbers.
Journal ArticleDOI
Stability of slowly diverging jet flow
D. G. Crighton,Michael Gaster +1 more
TL;DR: In this paper, coherent axisymmetric structures in a turbulent jet are modelled as linear instability modes of the mean velocity profile, regarded as the profile of a fictitious laminar inviscid flow.
Journal ArticleDOI
The noise from turbulence convected at high speed
TL;DR: In this article, the authors extended Lighthill's theory for the purpose of estimating the sound radiated from a turbulent fluid flow to deal with both the transonic and supersonic ranges of eddy convection speed.
Journal ArticleDOI
On the generation of sound by supersonic turbulent shear layers
TL;DR: In this paper, a convected wave equation (2.8) is derived to describe the generation and propagation of the pressure fluctuations in the supersonic turbulent shear zone.