Trailing edge noise data with comparison to theory

Olsen, W. A.; Boldman, D. R.

doi:10.2514/6.1979-1524

Cited by 13 publications

(19 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For further comments on their analysis, as well as others, the reader may refer to Crighton (1991), but none of the analyses or experiments addressed a resonant condition and the associated frequencies. Olsen & Boldman (1979), on the other hand, presented narrow-band spectral data; some did exhibit sharp spikes that must have been associated with discrete tones. Unfortunately, the physical configuration of the plate relative to the flow was not completely clear.…”

Section: Possible Mechanismmentioning

confidence: 95%

“…A few earlier works on trailing-edge noise are worth noting here. Yu & Tam (1978) and Olsen & Boldman (1979) reported experimental results on the interaction of a rectangular (slot) jet with a flat plate. Both, however, involved wall jets (i.e.…”

Section: Possible Mechanismmentioning

confidence: 98%

“…There is a body of literature on past experimental studies of trailing-edge noise and jet-wing and jet-flap interaction noise (e.g. Tam & Yu 1975;Yu & Tam 1978;Olsen & Boldman 1979;Way & Turner 1980;Miller 1983;SenGupta 1983;Brown & Ahuja 1984;Mead & Strange 1998;Mengle 2011). For a review of past analytical as well as experimental efforts in these areas an interested reader may refer to Crighton (1991).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An experimental investigation of resonant interaction of a rectangular jet with a flat plate

et al. 2015

View full text Add to dashboard Cite

The interaction between an 8:1 aspect ratio rectangular jet and a flat plate, placed parallel to the jet, is addressed in this study. At high subsonic conditions and for certain relative locations of the plate, a resonance takes place with accompanying audible tones. Even when the tone is not audible the sound pressure level spectra are often marked by conspicuous peaks. The frequencies of these peaks, as functions of the plate's length, its location relative to the jet as well as jet Mach number, are studied in an effort to understand the flow mechanism. It is demonstrated that the tones are not due to a simple feedback between the nozzle exit and the plate's trailing edge; the leading edge also comes into play in determining the frequency. With parametric variation, it is found that there is an order in the most energetic spectral peaks; their frequencies cluster in distinct bands. The lowest frequency band is explained by an acoustic feedback involving diffraction at the plate's leading edge. Under the resonant condition, a periodic flapping motion of the jet column is seen when viewed in a direction parallel to the plate. Phase-averaged Mach number data on a cross-stream plane near the plate's trailing edge illustrate that the jet cross-section goes through large contortions within the period of the tone. Farther downstream a clear 'axis switching' takes place for the time-averaged cross-section of the jet that does not occur otherwise for a non-resonant condition.

show abstract

Section: Possible Mechanismmentioning

confidence: 95%

Section: Possible Mechanismmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An experimental investigation of resonant interaction of a rectangular jet with a flat plate

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Most literature deals with analytical theories of acoustics of Amiet, Lighthill and Ffowcs-Williams, which are limited to low Mach number, incompressible flow (Jones and Sandberg 2012;Olsen and Boldman 1979). Howe (1991bHowe ( , 1999 used these theories in numerous papers for the analytical prediction of noise and the generation of sound waves in various geometrical cases.…”

Section: List Of Symbolsmentioning

confidence: 99%

Investigation of wave phenomena on a blunt airfoil with straight and serrated trailing edges

et al. 2015

View full text Add to dashboard Cite

“…The noise amplification associated with jet--surface interaction was investigated experimentally by Scharton et al [11] in the context of aerofoil flap noise. Figure (13) in their paper indicates that the trailing edge interaction effect (with the flap alligned with the airfoil) is almost 10 dB greater than the jet noise at the peak frequency of the jet noise ninety-degree spectrum. The Scharton et al experiment was at an acoustic Mach number ( Ma = U J c ∞ , where U J is the jet exit velocity and c ∞ is the ambient speed of sound) of about 0.5 (corresponding to a jet speed of 550 ft s ) for a jet--aerofoil flap configuration, however, Head & Fisher [12] obtained similar low frequency amplification results (see their Fig.…”

mentioning

confidence: 97%

Effect of de-correlating turbulence on the low frequency decay of jet-surface interaction noise in sub-sonic unheated air jets using a CFD-based approach

Afsar

Leib

Bozak

2017

Journal of Sound and Vibration

View full text Add to dashboard Cite

In this paper we extend the Rapid-distortion theory (RDT)-based model derived by Goldstein, Afsar & Leib (J. Fluid Mech., vol. 736, pp. 532-569, 2013) for the sound generated by the interaction of a large-aspect-ratio rectangular jet with the trailing edge of a flat plate to include a more realistic upstream turbulence spectrum that possess a de-correlation (i.e. negative dip) in its space-time structure and use results from three-dimensional Reynolds-Averaged Navier-Stokes (RANS) solutions to determine the mean flow, turbulent kinetic energy and turbulence length & time scales. Since the interaction noise dominates the low-frequency portion of the spectrum, we use an appropriate asymptotic approximation for the Rayleigh equation Green’s function, which enters the analysis, based on a two-dimensional mean flow representation for the jet. We use the model to predict jet-surface interaction noise for a range of subsonic acoustic Mach number jets, nozzle aspect ratios, streamwise and transverse trailing-edge locations and compare them with experimental data. The RANS meanflow computations are also compared with flow data for selected cases to assess their validity. We find that finite de-correlation in the turbulence spectrum increases the low-frequency algebraic decay (the low-frequency “roll-off”) of the acoustic spectrum with angular frequency to give a model that has a pure dipole frequency scaling. This gives better agreement with noise data compared to Goldstein et al. (2013) for Strouhal numbers less than the peak jet-surface interaction noise. For example, through sensitivity analysis we find that there is a difference of 10 dB at the lowest frequency for which data exists (relative to a model without de-correlation effects included) for the highest acoustic Mach number case. Secondly, our results for the planar flow theory provide a first estimate of the low-frequency amplification due to the jet-surface interaction for moderate aspect ratio nozzles when RANS meanflow quantities are used appropriately. This work will hopefully add to noise prediction efforts for aircraft configurations in which the exhaust systems are tightly integrated with the airframe

show abstract

Trailing edge noise data with comparison to theory

Cited by 13 publications

References 12 publications

An experimental investigation of resonant interaction of a rectangular jet with a flat plate

An experimental investigation of resonant interaction of a rectangular jet with a flat plate

Investigation of wave phenomena on a blunt airfoil with straight and serrated trailing edges

Effect of de-correlating turbulence on the low frequency decay of jet-surface interaction noise in sub-sonic unheated air jets using a CFD-based approach

Contact Info

Product

Resources

About