Modeling supersonic jet screech 2 - Acoustic radiation from the shock-vortex interaction

1995 ◽  
Author(s):  
E Kerschen ◽  
A Cain
Keyword(s):  
Acoustic Radiation ◽  
Supersonic Jet ◽  
Vortex Interaction

Exploration of temperature effects on the far-field acoustic radiation from a supersonic jet

2014 ◽  
Author(s):  
Haukur E. Hafsteinsson ◽  
Lars-Erik Eriksson ◽  
Niklas Andersson ◽  
Pablo A. Mora Sanchez ◽  
Ephraim J. Gutmark ◽  
...  
Keyword(s):  
Temperature Effects ◽  
Acoustic Radiation ◽  
Supersonic Jet ◽  
Far Field

Validation of a High-Order Large Eddy Simulation Solver for Acoustic Prediction of Supersonic Jet Flow

2020 ◽  
Vol 28 (03) ◽  
pp. 1950023
Author(s):  
Weiqi Shen ◽  
Steven A. E. Miller
Keyword(s):  
Large Eddy Simulation ◽  
Large Scale ◽  
Acoustic Radiation ◽  
Supersonic Jet ◽  
High Order ◽  
High Order Accuracy ◽  
Order Of Accuracy ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Mixing Noise

A high-order large eddy simulation (LES) code based on the flux reconstruction (FR) scheme is further developed for supersonic jet simulation. The FR scheme provides an efficient and easy-to-implement way to achieve high-order accuracy on an unstructured mesh. The order of accuracy and the shock capturing capability of the solver are validated with the isentropic Euler vortex and Sod’s shock tube problem. A heated under-expanded supersonic jet case from NASA’s Small Hot Jet Acoustic Rig (SHJAR) database is used for validation. The turbulence statistics along the nozzle centerline and lip-line are examined. We predict the acoustic radiation with the Ffowcs Williams and Hawkings method, which is integrated with our solver. The far-field acoustic predictions show reasonable agreement with the experimental measurement in the upstream and downstream directions, where the shock-associated noise and the large-scale turbulent mixing noise are dominant, respectively.

Supersonic cooling by shock–vortex interaction

1996 ◽  
Vol 308 ◽  
pp. 363-379 ◽  
Author(s):  
M. D. Fox ◽  
M. Kurosaka
Keyword(s):  
Heat Transfer ◽  
Supersonic Jet ◽  
Vortex Interaction ◽  
Vortical Structures ◽  
The Past ◽  
Impingement Plate ◽  
Temperature Separation ◽  
Total Temperature ◽  
The Subject ◽  
Theoretical Results

The subject of total temperature separation in jets was treated in Fox et al. (1993) for subsonic jets. When we extended this study to the case of supersonic jets, we found the presence of a different mechanism of cooling, an effect which does not appear to have been known in the past. Named the ‘shock-induced total temperature separation’, this cooling can be of much greater magnitude than the subsonic cooling treated previously; it is caused by the interaction of convected vortical structures near the jet exhaust with the shock structure of the supersonic jet.In studying this phenomenon, we focus our attention on overexpanded jets exiting a convergent-divergent nozzle. The theoretical results for the shock-induced cooling which are based on a linearized, unsteady supersonic analysis are shown to agree favourably with experiments.When an impingement plate is inserted, the shock-induced cooling would manifest itself as wall cooling, whose magnitude is significantly larger than the subsonic counterpart. This has implications for heat transfer not only in jets, but wherever vortical structures may interact with shock waves.

Mach waves produced in the supersonic jet mixing layer by shock/vortex interaction

Shock Waves ◽  
2016 ◽  
Vol 26 (3) ◽  
pp. 231-240 ◽  
Author(s):  
H. Oertel Sen ◽  
F. Seiler ◽  
J. Srulijes ◽  
R. Hruschka
Keyword(s):  
Mixing Layer ◽  
Supersonic Jet ◽  
Vortex Interaction ◽  
Jet Mixing ◽  
Mach Waves

scholarly journals Influence of Different Configurations of Microjet Injection on Structure and Acoustic Radiation of Supersonic Jet

2019 ◽  
Vol 14 (2) ◽  
pp. 56-76
Author(s):  
D. A. Gubanov ◽  
S. G. Kundasev ◽  
L. P. Trubitsyna
Keyword(s):  
Acoustic Radiation ◽  
Supersonic Jet ◽  
Jet Noise ◽  
Geometrical Parameters ◽  
Injection Point ◽  
Longitudinal Vortices ◽  
Supersonic Underexpanded Jet ◽  
Pressure Profiles ◽  
Pitot Pressure ◽  
Quantity Effect

The work is devoted to experimental study of the structure and acoustic radiation of a supersonic underexpanded jet Ma = 1, Npr = 5 with the presence of vortexgenerators in the form of small-sized jets injections. Ten different configurations were tested, in which following the gas-dynamic and geometrical parameters of the microjets were changed one by one: microjets pressure, the injection distance from the main nozzle section, azimuthal, tangential, and axial angles of micronozzles inclination. The flow visualization, azimuthal Pitot pressure profiles and characteristics of jet noise in the far field were obtained. It has been revealed that the injection of microjets in general leads to an increase in the jet long-range and a decrease in its mixing. The advantageous parameters of the microjets injection for reducing the jet acoustic emission are the injection point vicinity to the main nozzle section, micronozzles inclination to main jet axis and the small tangential angle of micronozzles. The micronozzles quantity effect is non-linearly in relation to the structure and the jet noise. The average pressure measuring distribution near artificial longitudinal vortices in a jet stream cannot predict the characteristics of its mixing and acoustic radiation.

Experiments on the instability waves in a supersonic jet and their acoustic radiation

1975 ◽  
Vol 69 (1) ◽  
pp. 73-95 ◽  
Author(s):  
Dennis K. Mclaughlin ◽  
Gerald L. Morrison ◽  
Timothy R. Troutt
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Large Scale ◽  
Acoustic Radiation ◽  
Low Reynolds Number ◽  
Supersonic Jet ◽  
Hot Wire ◽  
Theoretical Predictions ◽  
Low Reynolds ◽  
High Reynolds

An experimental investigation of the instability and the acoustic radiation of the low Reynolds number axisymmetric supersonic jet has been performed. Hot-wire measurements in the flow field and microphone measurements in the acoustic field were obtained from different size jets at Mach numbers of about 2. The Reynolds number ranged from 8000 to 107000, which contrasts with a Reynolds number of 1·3 × 106for similar jets exhausting into atmospheric pressure.Hot-wire measurements indicate that the instability process in the perfectly expanded jet consists of numerous discrete frequency modes around a Strouhal number of 0·18. The waves grow almost exponentially and propagate downstream at a supersonic velocity with respect to the surrounding air. Measurements of the wavelength and wave speed of theSt= 0·18 oscillation agree closely with Tam's theoretical predictions.Microphone measurements have shown that the wavelength, wave orientation and frequency of the acoustic radiation generated by the dominant instability agree with the Mach wave concept. The sound pressure levels measured in the low Reynolds number jet extrapolate to values approaching the noise levels measured by other experimenters in high Reynolds number jets. These measurements provide more evidence that the dominant noise generation mechanism in high Reynolds number jets is the large-scale instability.

Global modes and transient response of a cold supersonic jet

2011 ◽  
Vol 669 ◽  
pp. 225-241 ◽  
Author(s):  
JOSEPH W. NICHOLS ◽  
SANJIVA K. LELE
Keyword(s):  
Acoustic Radiation ◽  
Near Field ◽  
Supersonic Jet ◽  
Mode Analysis ◽  
Wave Radiation ◽  
Far Field ◽  
Transient Growth ◽  
Global Mode ◽  
Laminar Jet ◽  
Global Modes

Global-mode analysis is applied to a cold, M = 2.5 laminar jet. Global modes of the non-parallel jet capture directly both near-field dynamics and far-field acoustics which, in this case, are coupled by Mach wave radiation. In addition to type (a) modes corresponding to Kelvin–Helmholtz instability, it is found that the jet also supports upstream-propagating type (b) modes which could not be resolved by previous analyses of the parabolized stability equations. The locally neutrally propagating part of a type (a) mode consists of the growth and decay of an aerodynamic wavepacket attached to the jet, coupled with a beam of acoustic radiation at a low angle to the jet downstream axis. Type (b) modes are shown to be related to the subsonic family of modes predicted by Tam & Hu (1989). Finally, significant transient growth is recovered by superposing damped, but non-normal, global modes, leading to a novel interpretation of jet noise production. The mechanism of optimal transient growth is identified with a propagating aerodynamic wavepacket which emits an acoustic wavepacket to the far field at an axial location consistent with the peaks of the locally neutrally propagating parts of type (a) modes.

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