Prediction of Broadband Shock-Associated Noise Using Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics

Morris, Philip J.; Miller, Steven A.

doi:10.2514/1.j050560

Cited by 61 publications

(81 citation statements)

References 21 publications

(48 reference statements)

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“…21,22 The 125 PSD has a rounder shape and reveals a secondary high-frequency peak around 20 kHz. Though not shown, the angular variation in the PSD shapes for the Mach 1.8 jet match published curves of jet mixing and broadband shock-associated noise 20,23 in which the high-frequency secondary peak at similar angles is caused by shockassociated noise. (See 120 data in Fig.…”

Section: Results and Analysissupporting

confidence: 53%

Skewness and shock formation in laboratory-scale supersonic jet data

Gee

Neilsen

Atchley

2013

The Journal of the Acoustical Society of America

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Spatial properties of noise statistics near unheated, laboratory-scale supersonic jets yield insights into source characteristics and near-field shock formation. Primary findings are (1) waveforms with positive pressure skewness radiate from the source with a directivity upstream of maximum overall level and (2) skewness of the time derivative of the pressure waveforms increases significantly with range, indicating formation of shocks during propagation. These results corroborate findings of a previous study involving full-scale engine data. Further, a comparison of ideally and over-expanded laboratory data show that while derivative skewness maps are similar, waveform skewness maps are substantially different for the two cases.

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Section: Results and Analysissupporting

confidence: 53%

Skewness and shock formation in laboratory-scale supersonic jet data

Gee

Neilsen

Atchley

2013

The Journal of the Acoustical Society of America

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“…27 The cases represent over-expanded and under-expanded conditions over a range of Mach numbers for a convergent and convergent-divergent nozzle. The nozzles and operating conditions are shown in Table 1 and the T T R varies from 1.00 to 4.00 for each case.…”

Section: Resultsmentioning

confidence: 99%

The Scaling of Broadband Shock-Associated Noise with Increasing Temperature

Miller

2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

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A physical explanation for the saturation of broadband shock-associated noise (BBSAN) intensity with increasing jet stagnation temperature has eluded investigators. An explanation is proposed for this phenomenon with the use of an acoustic analogy. For this purpose the acoustic analogy of Morris and Miller is examined. To isolate the relevant physics, the scaling of BBSAN at the peak intensity level at the sideline (ψ = 90 degrees) observer location is examined. Scaling terms are isolated from the acoustic analogy and the result is compared using a convergent nozzle with the experiments of Bridges and Brown and using a convergent-divergent nozzle with the experiments of Kuo, McLaughlin, and Morris at four nozzle pressure ratios in increments of total temperature ratios from one to four. The equivalent source within the framework of the acoustic analogy for BBSAN is based on local field quantities at shock wave shear layer interactions. The equivalent source combined with accurate calculations of the propagation of sound through the jet shear layer, using an adjoint vector Green's function solver of the linearized Euler equations, allows for predictions that retain the scaling with respect to stagnation pressure and allows for the accurate saturation of BBSAN with increasing stagnation temperature. This is a minor change to the source model relative to the previously developed models. The full development of the scaling term is shown. The sources and vector Green's function solver are informed by steady Reynolds-Averaged Navier-Stokes solutions. These solutions are examined as a function of stagnation temperature at the first shock wave shear layer interaction. It is discovered that saturation of BBSAN with increasing jet stagnation temperature occurs due to a balance between the amplification of the sound propagation through the shear layer and the source term scaling. Component of the vector Green's function of the linearized Euler equations xStreamwise direction x = x(x, y, z)Vector observer position y = y(x, y, z)Vector source position from the primary nozzle exit β Off-design parameter γ Ratio of specific heats δ Dirac delta function ǫ Dissipation rate of turbulent kinetic energy η = η (ξ, η, σ) Vector between two source locations λ Parameter equal to ω sin θ/c ∞ π IntroductionAircraft, rockets, and many other vehicles use jet engines as their means of propulsion. The noise produced by jet plumes is often problematic both physically 1 and psychologically. 2 For example, civilian and military aircraft operating in the vicinity of airports can be an annoyance to the community 3 due to jet noise. During take-off, noise from the jet exhaust often dominates other aircraft noise sources.4 High speed supersonic jet flows cause hearing loss for military personnel during carrier landing and take-off and on military practice fields.5 If aircraft cruise a component of the cabin noise is due to jet noise. The loading induced by jet noise can cause sonic fatigue on aircraft and rocket engines.1 Rockets used to place...

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“…He also suggested from the observation of the static pressure measurements by Norum and Seiner [12] that strong screech tones cause a rapid disintegration of the shock-cell structure, leading to the BBSAN attenuation. More recently, Morris and Miller [27] proposed two sets of calibration constants inside their numerical model for BBSAN prediction, designed specifically for the cases of screeching and non-screeching jets. The strong screech tones observed by the authors under flight conditions [22] also induced a strong attenuation of the BBSAN (see Fig.…”

Section: Introductionmentioning

confidence: 99%

Broadband Shock-Associated Noise in Screeching and Non-Screeching Underexpanded Supersonic Jets

2013

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The effect of screech tones on the broadband shock-associated noise of underexpanded jets is investigated experimentally. Screech is removed by means of a notched nozzle, and the properties of the broadband shockassociated noise in the screech-free configuration are compared to that in a screeching flow. It is first demonstrated that the suppressing technique used is nonintrusive in that it does not alter the shock-cell structure of the jet plume. It is then shown that screech has an effect on the aerodynamics of the jet, which induces changes in the broadband shockassociated noise. Indeed, screech accelerates the damping of the shock-cell pattern, leading to an attenuation of the broadband shock-associated noise and a shifting of this noise component to higher frequencies. Moreover, a tuning between the peak frequency of the broadband shock-associated noise and the screech frequency is observed. It is also deduced from the directivity of the broadband shock-associated noise in the far field that the convective velocity in the shear layer is modified in the presence of screech tones.

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Prediction of Broadband Shock-Associated Noise Using Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics

Cited by 61 publications

References 21 publications

Skewness and shock formation in laboratory-scale supersonic jet data

Skewness and shock formation in laboratory-scale supersonic jet data

The Scaling of Broadband Shock-Associated Noise with Increasing Temperature

Broadband Shock-Associated Noise in Screeching and Non-Screeching Underexpanded Supersonic Jets

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