The role of screech tones in mixing of an underexpanded rectangular jet

Krothapalli, Anjaneyulu; Hsia, Y.; Baganoff, D.; Karamcheti, K.

doi:10.1016/s0022-460x(86)80177-8

Cited by 153 publications

(71 citation statements)

References 14 publications

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“…Whereas screech frequency is controlled by the feedback acoustic waves, the screech intensity is governed primarily by the characteristics of the downstream propagating flow disturbances and their interaction with the shock-cell structures. Several detailed measurements [10,12,15,[19][20][21][22][23] and numerical viscous simulations [10,[24][25][26][27][28][29] have been reported and served to throw light on the subject. The experimental description of A-D mode switch (A1 , A2 , B, C, D) according to the jet operating parameters represents a notable step [12].…”

Section: Introductionmentioning

confidence: 99%

Shock-Refracted Acoustic Wave Model for Screech Amplitude in Supersonic Jets

Kandula

2008

AIAA Journal

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Section: Introductionmentioning

confidence: 99%

Shock-Refracted Acoustic Wave Model for Screech Amplitude in Supersonic Jets

Kandula

2008

AIAA Journal

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“…Raman [46] notes that in such jets, the screech field often consists of a "feedback shock", or sound waves with a compact wave forms, which appear to originate from a single source. They are visible in photographs appearing in Raman [44,46], Poldervaart et al [37], Hammitt [7], and Krothapalli et al [18], all of which were based on high aspect ratio supersonic jet flows. The dominance of a feedback shock is also clear in the acoustic measurements of Krothapalli et al [18]; the fundamental frequency is dominant in all directions, suggesting the absence of multiple sources.…”

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confidence: 99%

“…It is well known that the flapping mode of the rectangular screeching jet can be more intense than the flapping modes of the round jet [18]. It is proposed that the compact waveform of the feedback shock is due to the periodic leakage of the shock cell structure.…”

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confidence: 99%

A numerical investigation of sound generation in supersonic jet screech

Manning

Lele

2000

6th Aeroacoustics Conference and Exhibit

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including gathering and maintaining the data needed, and completing and reviewing the collection of information. Send collection of information, including suggestions for reducing this burden, to Washington Headquarters Services Davis Highway, Suite 1 204, Arlington, VA 22202-4302, and fcV-tW 0Vf*si?of Management and Budget, Paper« AGENCY USE ONLY (Leave blank)2. REPORT DATE 11/29/00 REPORV-AFRL-SR-BL-TR-00-öürtl i. mm UM I i:a lUVbHbU 04/01/98-'09/30/00 TITLE AND SUBTITLE(U) A Numerical Investigation of Sound Generation in Supersonic JET Screech AUTHOR(S)Ted A. Manning and Sanjiva K. Lele FUNDING NUMBERSF49620-98-1-0355 The noise : i supersonic jet flows is due in part to the interaction between jet instability waves and the jet shock-cell structure. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)DEPARTMENTThe emitted shock-cell noise re-excites certain instability wave modes at the nozzle lip and causes resonant feedback to occur. This feedback resonance, known as supersonic jet screech, causes the jet to flap violently at discrete frequencies and generate very strong, narrow-banded tones. Jet screech is a source of acoustic fatigue in the tail and nozzle structures of supersonic aircraft. It is therefore important that methods for predicting the screech amplitude be developed.In the present research we investigate the screech sound generation process, particularly for high amplitude instability waves. We isolate the interaction of an unsteady shear layer with a single oblique shock. To obtain an overall understanding of the phenomenon with fewest simplifications, we study this problem through the numerical solution of the Navier-Stokes equations. We then consider idealizations to obtain a similar but wider range of results with specially linearbed Euler equations. These results motivate the use of geometric acoustics to describe the screech generation process. The Navier-Stokes and Euler simulations have revealed important details about the interaction process, how the acoustic field results, and why the screech is so loud. AbstractThe noise of supersonic jet flows is due in part to the interaction between jet instability waves and the jet shock-cell structure. If no counter-measures are taken, the emitted shock-cell noise will re-txcite certain instability wave modes at the nozzle lip and cause resonant feedback to occur. This feedback resonance, known as supersonic jet screech, causes the jet to flap violently at discrete frequencies and generate very strong, narrow-banded tones. Jet screech has been shown to be a source of acoustic fatigue in the tail and nozzle structures of supersonic aircraft. It is therefore important that methods for predicting the screech amplitude be developed. While comprehensive screech models will require taking all elements of the feedback loop into consideration, a basic understanding of each element in isolation will also be necessary. Screech sound generation is one such ...

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“…Very little other work has examined possible compressibility effects at high subsonic or supersonic jet Mach numbers -according to the review of Gutmark and Grinstein 8 this is principally the experiments of Krothapalli et al 15 and Gutmark et al 16 . These studies observed two extra effects on jet mixing introduced by supersonic and improperly expanded jet conditions (in addition to the screech-induced axial forcing already mentioned Installed nozzles will often have at least one side where nearby solid surfaces restrict entrainment into the jet plume.…”

Section: Introductionmentioning

confidence: 99%