2006 Fiscal Year Final Research Report Summary
Reduction in Supersonic Jet Noise from a Laval Nozzle available in Various Industry and Development of a High Efficiency Nozzle
Project/Area Number |
16560148
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Fluid engineering
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Research Institution | The University of Kitakyushu (2006) Kyushu University (2004-2005) |
Principal Investigator |
MIYAZATO Yoshiaki The University of Kitakyusyu, Faculty of Environmental Engineering, Associate Professor, 国際環境工学部, 助教授 (30253537)
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Project Period (FY) |
2004 – 2006
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Keywords | Laval nozzle / Supersonic jet / Noise reduction technique / Screech tone / Pitot pressure / Nozzle lip / Schlieren method |
Research Abstract |
The present paper describes the experimental investigations on reduction in supersonic jet noise from a Laval nozzle available in various industry and development of a high efficiency nozzle. A design Mach number of the nozzle is 2.0 with the throat diameter of 20mm and the nozzle exit diameter of 26mm. The experiments have been conducted over a range of nozzle pressure ratios from 2.0 to 18.0 including the overexpanded and the underexpanded jets. The measurements were conducted in an anechoic room providing a free-field environment. Schlieren technique was used as the tool to study qualitatively the shock wave patterns which are primarily responsible for screech tones. The effect of the nozzle-lip thickness on screech tones has been investigated experimentally. As a result, for the nozzle-lip thickness below one nozzle exit diameter, the screech tone amplitude at the overexpanded condition increases with increasing the nozzle-lip thickness, and the jet oscillation mode changes from ax
… More
isymmetric to spiral or flapping, while for the nozzle-lip thickness beyond the two nozzle exit diameter, the screech tone amplitude decreases with increasing the nozzle-lip thickness. Two new techniques on supersonic jet noise reduction are proposed, one is the method by a cross-wire which is composed of long cylinders with a very small diameter and its location is varied in the jet axis direction in the supersonic jet stream, the other a mesh screen which is long stainless wires with a very small diameter. The cross-wire is significantly affects the jet structure. Schlieren photographs show that the cross-wire destroys the shock cell structure and weakens the strength. Therefore, the wire reduces the amplitude of screech tones. The mesh screen is perpendicularly placed at the nozzle exit plane and the hole is perforated in the central part of the screen to perturb the initial jet shear layer. The mesh screen leads to a substantial suppression of jet screech tones and the over all sound pressure level. The hole size is an important factor in reducing the supersonic jet noise. Less
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Research Products
(20 results)
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[Journal Article] Control of Supersonic Jet Noise Using a Mesh Screen2006
Author(s)
Kweon, Y.H., Lim, C.M.Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
Proc. of the 13th International Congress on Sound and Vibration (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] An Experimental Study of the Nozzle-Lip Thickness Effect on Supersonic Jet Screech Tones2006
Author(s)
Aoki, T., Kweon, Y.H., Miyazato, Y., Kim, H.D., Setoguchi, T.
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Journal Title
J. Mechanical Science and Technology Vo1.20,No.4
Pages: 522-532
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] A New Control Technique of the Supersonic Jet Using a Wire Device2005
Author(s)
Kweon, Y.H., Lim, C.M., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
Proc. of the 6th KSME-JSME Thermal Fluid Engineering Conference (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] The Effect of a Cross Wire Device in Supersonic Jet Noise2005
Author(s)
Kweon, Y.H., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
AIAApaper No.2005-2891, (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] The Effect of a Reflector Size on the Flow-Field in Supersonic Jet2005
Author(s)
Kweon, Y.H.H., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
Proc. of the 8th International Symposium on Fluid Control, Measurement and Visualization (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Effect of Sound-Absorbing Materials on the Characteristics of Supersonic Jet Noise2005
Author(s)
Kweon, Y.H.H., Tsuchida, Y., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
Proc. of the 7th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Effect of Reflector on the Flow Features of Supersonic Jet2005
Author(s)
Kweon, Y.H, Nishiyama, Y., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
Proc. of the 7th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] The Effect of Reflector with Sound-Absorbing Material on Supersonic Jet Noise2005
Author(s)
Kweon, Y.H., Tsuchida, M., Miyazato, Y., Aoki, T., Kim, H.D., Setoguchi, T.
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Journal Title
J. Thermal Science Vo1.14,No.1
Pages: 22-27
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Experimental Investigation on Supersonic Jet Noise from Convergent-Divergent Nozzle2004
Author(s)
Miyazato, Y., Aoki, T., Kondoh, N., Masuda, M., Kweon, Y.H., Kim, H.D., Setoguchi, T., Matsuo, K.
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Journal Title
Proc. of the 24th International Shock Wave Symposium (CD-ROM)
Description
「研究成果報告書概要(欧文)」より
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