Experimental and Computational Study of Near Field/Far Field Correlations in Supersonic Jet Noise

Kuo, Ching Wen; Du, Yongle; McLaughlin, Dennis K.; Morris, Philip J.

doi:10.2514/6.2012-1170

Cited by 9 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results also suggest that high-frequency fluctuations are generally convected at a higher phase velocity as compared to lowfrequency fluctuations. Since the experimental measurements are not available, similar results are referenced from the authors' previous study [32], where a good agreement was found.…”

Section: Statistics Of the Near-field Turbulent Structuressupporting

confidence: 52%

The separation of radiating and non-radiating near-field pressure fluctuations in supersonic jets

Morris

2015

Journal of Sound and Vibration

Self Cite

View full text Add to dashboard Cite

Section: Statistics Of the Near-field Turbulent Structuressupporting

confidence: 52%

The separation of radiating and non-radiating near-field pressure fluctuations in supersonic jets

Morris

2015

Journal of Sound and Vibration

Self Cite

View full text Add to dashboard Cite

“…[38][39][40][41] An expression for the three-dimensional sound field is written by Papamoschou 39 as…”

Section: A Simulated Input and Output Fieldsmentioning

confidence: 99%

Proper orthogonal decomposition-based spectral higher-order stochastic estimation

Baars

Tinney

2014

Physics of Fluids

View full text Add to dashboard Cite

A unique routine, capable of identifying both linear and higher-order coherence in multiple-input/output systems, is presented. The technique combines two well-established methods: Proper Orthogonal Decomposition (POD) and Higher-Order Spectra Analysis. The latter of these is based on known methods for characterizing nonlinear systems by way of Volterra series. In that, both linear and higher-order kernels are formed to quantify the spectral (nonlinear) transfer of energy between the system's input and output. This reduces essentially to spectral Linear Stochastic Estimation when only first-order terms are considered, and is therefore presented in the context of stochastic estimation as spectral Higher-Order Stochastic Estimation (HOSE). The trade-off to seeking higher-order transfer kernels is that the increased complexity restricts the analysis to single-input/output systems. Low-dimensional (POD-based) analysis techniques are inserted to alleviate this void as POD coefficients represent the dynamics of the spatial structures (modes) of a multi-degree-of-freedom system. The mathematical framework behind this POD-based HOSE method is first described. The method is then tested in the context of jet aeroacoustics by modeling acoustically efficient large-scale instabilities as combinations of wave packets. The growth, saturation, and decay of these spatially convecting wave packets are shown to couple both linearly and nonlinearly in the near-field to produce waveforms that propagate acoustically to the far-field for different frequency combinations.

show abstract

“…And so, an adequate means by which the source mechanisms, responsible for generating Mach waves, can be isolated and studied remains to be found. A resurgence in recent years with the use of wave packets [42][43][44][45][46] may offer some relief, and at a reduced cost. Modeling the evolution of supersonically convecting large-scale instabilities by wave packets provides a theoretical framework for studying the noise radiated by supersonic jets.…”

Section: Sound Pressure Decay In the Jet Far Fieldmentioning

confidence: 99%

Coalescence in the Sound Field of a Laboratory-Scale Supersonic Jet

et al. 2016

View full text Add to dashboard Cite

The spatial evolution of acoustic waveforms produced by a laboratory-scale Mach 3 jet are investigated using both 1∕4 and 1∕8 in. pressure field microphones located along rays emanating from the postpotential core where the peak sound emission is found to occur. The measurements are acquired in a fully anechoic chamber, where ground or other large surface reflections are minimal. Various statistical metrics are examined along the peak emission path, where they are shown to undergo rapid changes within 2 m from the source region. An experimentally validated wave-packet model is then used to confirm the location where the pressure amplitude along the peak emission path transitions from cylindrical to spherical decay. Various source amplitudes, provided by the wave-packet model, are then used to estimate shock formation distance and Gol'dberg numbers for diverging waves. The findings suggest that cumulative nonlinear distortion is likely to occur at laboratory scale near the jet flow, where the waveform amplitude decays cylindrically, but less likely to occur farther from the jet flow, where the waveform amplitude decays spherically. Direct inspection of the raw time series reveals how steepened waveforms are generated by roguelike waves that form from the constructive interference of waves from neighboring sources as opposed to classical cumulative nonlinear distortion.

show abstract

Experimental and Computational Study of Near Field/Far Field Correlations in Supersonic Jet Noise

Cited by 9 publications

References 22 publications

The separation of radiating and non-radiating near-field pressure fluctuations in supersonic jets

The separation of radiating and non-radiating near-field pressure fluctuations in supersonic jets

Proper orthogonal decomposition-based spectral higher-order stochastic estimation

Coalescence in the Sound Field of a Laboratory-Scale Supersonic Jet

Contact Info

Product

Resources

About