Experimental investigations of screech mitigation and amplification by beveled and double-beveled nozzles
Experimental investigations of screech mitigation and amplification by beveled and double-beveled nozzles
An experimental study was conducted to investigate and compare the effects of beveled and double-beveled circular nozzles on supersonic jet screech at a nozzle pressure ratio of 5. In particular, near- and far-field microphone measurements and schlieren visualizations were utilized to look into selected acoustic and flow features associated with jet screech radiation. Results show that beveled nozzles eliminate jet screech by producing asymmetric shock structures and instability waves that are mismatched in phase and amplitude. In contrast, double-beveled nozzles produce symmetric shock structures and amplify screech intensity, even when jet mixing effects have been significantly enhanced. It is further observed that amplified jet screeches produced by double-beveled nozzles are highly unsteady and undergo nonperiodic and stochastic temporal variations. Last but not least, double-beveled nozzles also significantly impact screech peak noise locations and confer different changes along different measurement planes. The present study demonstrates that not all beveled-type nozzles are able to mitigate jet screech, with nonoptimal designs amplifying it instead.
Acoustic measurements, Lip-modified nozzle, Screech, Shock noise, Supersonic jet noise
Wei, X F
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Chua, L P
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Lu, Z B
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Lim, Desmond
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Mariani, R
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Cui, Y D
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New, T.H.
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Wei, X F
4fd4e67e-ec69-4c1e-8e81-7ce59790f668
Chua, L P
ed4f220c-71c3-44db-9479-eb42d3c56d79
Lu, Z B
c173a631-7999-4b2a-b93d-4fd5e90bba5b
Lim, Desmond
82a7e7e8-2ade-44f8-a342-a99c2b9339c4
Mariani, R
aea88ba3-506f-4cb6-964a-273050c0027e
Cui, Y D
eed2f6b6-0ac8-4e15-bd8e-1064a93713f4
New, T.H.
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Wei, X F, Chua, L P, Lu, Z B, Lim, Desmond, Mariani, R, Cui, Y D and New, T.H.
(2022)
Experimental investigations of screech mitigation and amplification by beveled and double-beveled nozzles.
Journal of Aerospace Engineering, 35 (4), [04022050].
(doi:10.1061/(asce)as.1943-5525.0001447).
Abstract
An experimental study was conducted to investigate and compare the effects of beveled and double-beveled circular nozzles on supersonic jet screech at a nozzle pressure ratio of 5. In particular, near- and far-field microphone measurements and schlieren visualizations were utilized to look into selected acoustic and flow features associated with jet screech radiation. Results show that beveled nozzles eliminate jet screech by producing asymmetric shock structures and instability waves that are mismatched in phase and amplitude. In contrast, double-beveled nozzles produce symmetric shock structures and amplify screech intensity, even when jet mixing effects have been significantly enhanced. It is further observed that amplified jet screeches produced by double-beveled nozzles are highly unsteady and undergo nonperiodic and stochastic temporal variations. Last but not least, double-beveled nozzles also significantly impact screech peak noise locations and confer different changes along different measurement planes. The present study demonstrates that not all beveled-type nozzles are able to mitigate jet screech, with nonoptimal designs amplifying it instead.
Text
(ASCE)AS.1943-5525.0001447
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Accepted/In Press date: 2 March 2022
e-pub ahead of print date: 28 April 2022
Additional Information:
Funding Information:
The present study was made possible by the financial support provided by the Singapore Ministry of Education AcRF Tier-2 Grant (Grant No. MOE2014-T2-1-002) and School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore. The authors also acknowledge facility support from Temasek Laboratories, National University of Singapore for the experiments conducted here.
Publisher Copyright:
© 2022 American Society of Civil Engineers.
Keywords:
Acoustic measurements, Lip-modified nozzle, Screech, Shock noise, Supersonic jet noise
Identifiers
Local EPrints ID: 468327
URI: http://eprints.soton.ac.uk/id/eprint/468327
ISSN: 0893-1321
PURE UUID: 30cf30fe-2b68-4b0e-8ad4-65919f4921e8
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Date deposited: 10 Aug 2022 18:09
Last modified: 05 Jun 2024 19:04
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Contributors
Author:
X F Wei
Author:
L P Chua
Author:
Z B Lu
Author:
R Mariani
Author:
Y D Cui
Author:
T.H. New
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