Shock associated noise of supersonic jets from convergent-divergent nozzles

Tam, Christopher K. W.; Tanna, H. K.

doi:10.1016/0022-460x(82)90244-9

Cited by 364 publications

(268 citation statements)

References 16 publications

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“…[6][7][8][9][10] The broadband contribution is also produced by the interaction of vortices with the shock cells but without feedback loop. [11][12][13] Although acoustically interesting and used in a large number of industrial sectors for discharging flow or generating pressure drops, acoustic radiation from a flow through a perforated plate or more generally from multiple jet nozzle has been very little studied in the literature. Among the few works on this subject, one can cite the work of Atvars et al 14 who studied the noise radiated by multitube nozzles and acoustically lined ejectors.…”

Section: Figure 1 Experimental Setup and Of Few Typical Samplesmentioning

confidence: 99%

Experimental investigation of the transient bleed valve noise

Laffay

Jacob

Moreau

et al. 2017

23rd AIAA/CEAS Aeroacoustics Conference

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This study presents the first step of an experimental study of the transient bleed valve noise. It was carried out on a simplified TBV geometry composed of a cylindrical inlet pipe leading to a diaphragm or a perforated disk for the purpose of generating pressure drops. Numerous diaphragms and grids have been tested in order to identify parameters that influence the acoustic radiation of the TBV and for NPR (Nozzle pressure ratio) from 1.2 to 3.6 to cover both subsonic and supersonic regimes. A large number of acoustic behaviors have been identified. For diaphragms far field acoustic spectra is dominated by mixing noise for all NPR and by shock-associated noise (screech and broadband shock associated noise (BBSAN)) when the critical value of the NPR delimiting the subsonic and supersonic behavior (NPRc = 1.89) is exceeded. For grids the mixing noise is still present but is composed of two humps. The parametric study allowed to associate the first hump to the noise of an equivalent jet having the smallest diameter encircling the grid perforations while the second is associated to the noise of the outer isolated jets. A first prediction model has thus been proposed based on this double source. Furthermore, the grids offer a significant noise reduction in the audible range with respect to a diaphragm of the same cross-section by shifting the radiation towards the high frequencies. The noise associated with supersonic phenomena (screech and BBSAN) are also strongly reduced and even suppressed in most of the tested cases.

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Section: Figure 1 Experimental Setup and Of Few Typical Samplesmentioning

confidence: 99%

Experimental investigation of the transient bleed valve noise

Laffay

Jacob

Moreau

et al. 2017

23rd AIAA/CEAS Aeroacoustics Conference

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“…The under performance at these conditions is thought to be due to the large screech amplitude reductions following the results of Jothi and Srinivasan [46], which indicate that reduction in screech amplitude can lead to amplification of broadband shock associated noise. The typical profile [47][48][49] is exhibited by all of the configurations investigated; shock noise generally increases with jet Mach number with a local minimum occurring near ideal expansion. The local minimum of the current data is slightly higher than the geometric design condition, a feature which is attributed to spectral amplification due to screech at the design condition as discussed above.…”

Section: Acoustic Fieldmentioning

confidence: 91%

Impact of chevron spacing and asymmetric distribution on supersonic jet acoustics and flow

Heeb

Gutmark

Kailasanath

2016

Journal of Sound and Vibration

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“…Tam and Tanna [15] put forth an equation relating the fully expanded jet diameter, D fej , and the exit diameter of the jet, D j . By using a shield to cover the region between the whistle and the jet inlet, it is seen that the exiting jet sticks to the wall of the shield without causing spill over around the cavity mouth, thus maintaining shock oscillation and jet regurgitance as seen in the un-shielded Hartmann whistle, which has intense flow/shock oscillation and spill over features near its mouth as already reported by Narayanan et al [11].…”

Section: Validationmentioning

confidence: 99%

Numerical simulation of jet flow impinging on a shielded Hartmann whistle

Michael¹,

Narayanan²,

H³

2015

International Journal of Aeronautical and Space Sciences

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The present study numerically investigates the effect of shield on the flow characteristics of Hartmann whistle. The flow characteristics of un-shielded Hartmann whistle are compared with whistles of different shield heights 15 mm, 17 mm, 20 mm, 25 mm and 30 mm. The comparison of Mach number contours and transient velocity vectors of shielded Hartmann whistles with un-shielded ones for the same conditions reveal that the presence of shield causes the exiting jet to stick to the wall of the shield without causing spill-over around the cavity inlet, thus sustaining the shock oscillation as seen in the unshielded Hartmann whistle, which has intense flow/shock oscillation and spill-over around the cavity mouth. The velocity vectors indicate jet regurgitance in shielded whistles showing inflow and outflow phases like un-shielded ones with different regurgitant phases. The sinusoidal variation of mass flow rate at the cavity inlet in un-shielded Hartmann whistle indicates jet regurgitance as the primary operating mode with large flow diversion around the cavity mouth whereas the non-sinusoidal behavior in shielded ones represent that the jet regurgitance is not the dominant operating mode. Thus, this paper sufficiently demonstrates the effect of shield in modifying the flow/shock oscillations in the vicinity of the cavity mouth.

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Shock associated noise of supersonic jets from convergent-divergent nozzles

Cited by 364 publications

References 16 publications

Experimental investigation of the transient bleed valve noise

Experimental investigation of the transient bleed valve noise

Impact of chevron spacing and asymmetric distribution on supersonic jet acoustics and flow

Numerical simulation of jet flow impinging on a shielded Hartmann whistle

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