Nozzle thrust optimization while reducing jet noise

Seiner, J. M.; Gilinsky, Mikhail

doi:10.2514/6.1995-2191

Cited by 13 publications

(9 citation statements)

References 3 publications

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“…To reduce both the shock associated and mixing noise, Dr. John M. Seiner patented a novel design that addresses both the imperfect expansion of the flow inside the nozzle while also enhancing mixing leading to a significant reduction in jet noise [11,12]. This new corrugated VEN seal concept was based on earlier work on the 'Telescope' and 'Bluebell' nozzles to reduce jet noise while optimizing thrust [13,14]. The increase in thrust came as a result of an "increase in nozzle internal surface area while maintaining nozzle projected area equivalent to the baseline reference" [13].…”

Section: Introductionmentioning

confidence: 99%

Performance Efficient Jet Noise Reduction for Supersonic Nozzles

Murray

Jansen

2012

International Journal of Aeroacoustics

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The variable area, round, axisymmetric, supersonic exhaust nozzle for high performance military aircraft represents a remarkable technological achievement. These variable exhaust nozzles (VEN) utilize conic contraction and expansion sections and provide a simple mechanical means to control the throat-to-exhaust area ratio as a function of throttle input while maintaining structural and thermal integrity. Despite this admirable design, the result is a jet that unavoidably includes shockwaves both inside the nozzle and in the exhaust. The sharp throat radius provides the potential for flow separation which is exacerbated by shock-boundary-layer interactions within the nozzle resulting in reduced pressure recovery on the wall which translates into reduced thrust. A novel design, patented by Dr. John M. Seiner, is shown to eliminate shocks by altering the contour of the VEN seals. This results in the elimination of shock noise in the far-field spectra. The shape of the contoured seals provides the added benefit of generating streamwise vorticity which is evident in the reduction in mixing noise in the far-field spectra. Particle image velocimetry data is presented to demonstrate the enhanced mixing that is generated. Experimental evidence obtained at both model scale and full-scale demonstrates the ability to obtain 2-5 dB noise reduction with an optimized contoured seal design.

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Section: Introductionmentioning

confidence: 99%

Performance Efficient Jet Noise Reduction for Supersonic Nozzles

Murray

Jansen

2012

International Journal of Aeroacoustics

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“…Various methods have proposed for reducing engine jet noise, without affecting other design parameters of the propulsion system. Some of these methods are the variable output nozzle using memory alloys [23][24][25], fan flow deflector [26][27][28] and the sinusoidal nozzles [29][30][31] as shown in Fig 4. Since 1996, many numerical and experimental studies on the performance of the serrated nozzles are conducted [32]. It can be concluded that the main source of noise in the nozzle is turbulent shear layer.…”

Section: Aeroacoustics In Aerospace Industriesmentioning

confidence: 99%

Synergy between Noise Reduction Techniques Applied in Different Industries: A Review

2020

IJM

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This review aims to assist aerodynamic noise in three industrial fields: Aerospace, Turbomachinery and Automotive. In this review the general terms in aeroacoustics is defined; and aerodynamic noise sources are recognized. The paper also reviews the brief literature on noise reduction techniques, with a particular focus on the state of the art numerical and experimental works. In Addition, developments in low speed designs for aerodynamic noise reduction, some passive and active methods for example serrated boundaries, porous media, noise absorber, and etc. are discussed. By investigating similarities in noise reduction techniques between these industries, this paper offers an outlook for noise reduction techniques in future.

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“…Also located in B1221A was a smaller anechoic chamber dubbed the Small Anechoic Room (SAR) which was used for sensor calibration, concept development, and research on small jet models. The SAR was 3.9 m × 3. study enhanced mixing concepts for axisymmetric nozzles using tabs, chevrons, and "Blue Bell" style nozzles ( Figure 9) [23,24].…”

Section: Small Anechoic Roommentioning

confidence: 99%

The Contributions of John M. Seiner towards Aeroacoustic Facilities and Experimental Techniques

Jansen

2012

International Journal of Aeroacoustics

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John M. "Jack" Seiner leaves behind a legacy of contributions to the science of Aeroacoustics. This memorial article concentrates on his contributions to the facilities and instrumentation he conceived, developed, and utilized to forward our understanding of jet noise, supersonic flows, and related acoustic issues. From his earliest days at NASA Langley Research Center in 1974, Jack worked to understand the physics of the problems he studied and strove to correctly model the physics of the problem at hand correctly in the laboratory. For jet noise research, this drove the requirement that the facility had to provide heated air to the model nozzle. Jack believed in the future of computational fluid dynamics and supported the development of codes to calculate shock containing jets and later advancements. When a facility capability or experimental technique did not exist to answer his questions, he worked to secure funding and develop these capabilities and techniques to demonstrate their value to aeroacoustic research. He was a pioneer in the study of twin-plume resonance and using propane fueled burners to achieve realistic jet plume conditions in the laboratory.

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Nozzle thrust optimization while reducing jet noise

Cited by 13 publications

References 3 publications

Performance Efficient Jet Noise Reduction for Supersonic Nozzles

Performance Efficient Jet Noise Reduction for Supersonic Nozzles

Synergy between Noise Reduction Techniques Applied in Different Industries: A Review

The Contributions of John M. Seiner towards Aeroacoustic Facilities and Experimental Techniques

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