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2004 Fiscal Year Final Research Report Summary

Control and Application of a Locked in Phenomenon of a Jet Screech/Self-Exited-Vibration by using a Spherical Reflector.

Research Project

Project/Area Number 15560201
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Dynamics/Control
Research InstitutionSAGA UNIVERSITY

Principal Investigator

SETO Kunisato  Saga University, Mechanical Engineering, Professor, 理工学部, 教授 (80039271)

Project Period (FY) 2003 – 2004
KeywordsSpherical Reflector / Jet Screech / Shock Wave / Self-Exited Vibration / Resonance / Noise Cancellation / Sound Shielding
Research Abstract

One of the purposes of the present research is to clarify the generation mechanism of jet screech. The special issues are interaction between vortex disturbances and a shock wave and a resonance mechanism caused through instability of shear layer near to the exit of a nozzle.
The next one is to control the jet screech by using a spherical reflector set at the nozzle exit that controls the location of an image noise source and cancels the jet screech.
(1)In order to identify the coherence of sound waves, a laser beam sound detector has been designed and built up. Fundamental data of the performance have been obtained through current investigations.
(2)Visual observation of the change in flow field by the attachment of a spherical reflector has been carried out by using a Schlieren system and a high speed video camera. It was found that the shock cell structure was kept up to downstream in case of the attachment of the spherical reflector. The reason is that cancellation of sound waves at t … More he nozzle exit quits exciting instability and stops generating disturbances. Hence the interaction between the disturbances and a shock wave becomes weak and the structure of the shock wave is not hampered.
(3)The above mentioned observation has been carried out through a spherical reflector with a slit hole. The slit hole lowered the level of the noise cancellation but still held the effect.
(4)Comparison of the sound cancellation effect between a spherical reflector and a flat plane reflector has been carried out.
(5)Comparison of the sound cancellation effect between a spherical reflector and a parabola reflector has been carried out.
(6)Sizing effect of a spherical reflector has been investigated by a variety of reflectors. It was confirmed that even a small sized spherical reflector could cancel a jet screech.
(7)Noise reducing effect of spherical reflectors has been studied at various pressure ratios and it was shown that there is an appropriate radius of curvature corresponding to each pressure ratio.
(8)In the above experiment, it was found that there was a special pressure ratio corresponding to any size of a spherical reflector where the noise reducing effect was highest.
(9)Preparation for the measurement of magnitude of resistance (thrust loss) of a spherical reflector in flow has been done.
(10)Preparation for the application of a spherical reflector to a duct silencer has been done. Less

  • Research Products

    (24 results)

All 2004 2003

All Journal Article (24 results)

  • [Journal Article] An Approach to Noise Reduction of a Supersonic Jet with a Spherical Reflector2004

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu, Hiromitsu Ohta
    • Journal Title

      Acoustical Science and Technology (Acoustical Society of Japan) 25・2

      Pages: 136-143

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Improvement of Performance of a Perforated Tube as a Noise Suppress or by Oblique Perforation2004

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu I
    • Journal Title

      JSME International Journal, B 47・3

      Pages: 605-611

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Aero-Acoustic Performance of a Forward Slanted Oblique Perforated Tube for Reducing Noise of a Supersonic Jet2004

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu, Takeshi MoriI
    • Journal Title

      International Journal of Acoustic and Vibration 19・1

      Pages: 23-29

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Jet Screech Reduction With a Spherical Reflector2004

    • Author(s)
      Md.Tawhidul Islam Khan, Kunisato Seto, Zhixiang Xu
    • Journal Title

      Proc.of 2^<nd> BSME-ASME International Conference on Thermal Engineering 1

      Pages: 433-438

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] A Comparison of Jet Noise Reduction with a Flat Reflector and a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu
    • Journal Title

      Proc.11^<th> ICSV Conference 1

      Pages: 401-406

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Aeroacoustic Modification of Jet Flow by a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul l IslamKhan, Zhixiang Xu
    • Journal Title

      Proc.11^<th> ICSV Conference 1

      Pages: 2475-2480

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Observations of Aero-Acoustic Modifications of a Supersonic Jet by using a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan
    • Journal Title

      The Journal of the Acoustical Society of America 116・4

      Pages: 2539-2539

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Control of Supersonic Jet Noise with a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan
    • Journal Title

      The Journal of the Acoustical Society of America 116・4

      Pages: 2539-2539

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] An Approach to Noise Reduction of a Supersonic Jet with a Spherical Reflector2004

    • Author(s)
      Md.Tawhidul Islam khan, Kimisato Seto, Zhixiang Xu, Hiromitsu Ohta
    • Journal Title

      Acoustical Science and Technology (Acoustical Society of Japan) Vol.25, No.2

      Pages: 136-143

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Improvement of Performance of a Perforated Tube as a Noise Suppressor by Oblique Perforation2004

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato, Seto, Zhixiang Xu
    • Journal Title

      JSME International Journal, B Vol.47, No.3

      Pages: 605-611

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Aero-Acoustic Performance of a Forward Slanted Oblique Perforated Tube for Reducing Noise of a Supersonic Jet2004

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu, Takeshi Mori
    • Journal Title

      International Journal of Acoustic and Vibration Vol.19, No.1

      Pages: 23-29

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Jet Screech Reduction with a Spherical Reflector2004

    • Author(s)
      Md.Tawhidul Islam Khan, Kunisato Seto, Zhixiang Xu
    • Journal Title

      Proc.of 2^<nd> BSME-ASME International Conference on Thermal Engineering Vol.1

      Pages: 433-438

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] A Comparison of Jet Noise Reduction with a Flat Reflector and a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhiriang Xu
    • Journal Title

      Proc.11^<th> ICSV Conference Vol.1

      Pages: 401-406

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Aeroacoustic Modification of Jet Flow by a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul 1 Islam Khan, Zhixiang Xu
    • Journal Title

      Proc.11^<th> ICSV Conference Vol.1

      Pages: 2475-2480

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Observations of Aero-Acoustic Modifications of a Supersonic Jet by using a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan
    • Journal Title

      The Journal of the Acoustical Society of America Vol.116, No.4

      Pages: 2539-2539

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Control of Supersonic Jet Noise with a Spherical Reflector2004

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan
    • Journal Title

      The Journal of the Acoustical Society of America Vol.116, No.4

      Pages: 2539-2539

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] The Effect of Spherical Surface on Noise suppression of a Supersonic Jet2003

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu, H.Ohta
    • Journal Title

      Journal of Thermal Science 12・2

      Pages: 144-150

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] The Effect of Spherical Surface on Jet Screech suppression2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu, H.Ohta
    • Journal Title

      Aerothermodynamics of Internal Flow 2

      Pages: 338-343

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Jet Noise Reduction by using a Spherical Reflector2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu
    • Journal Title

      Proc.internoise 2003 N1022

      Pages: 4325-4331

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Aeroacoustic Performance of Perforated Tube with Oblique Perforation2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu, Hiromitsu Ohta
    • Journal Title

      Proc.internoise 2003 N1023

      Pages: 4332-4337

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] The Effect of Spherical Surface on Noise suppression of a Supersonic Jet2003

    • Author(s)
      Md.Tawhidul Islam khan, Kunisato Seto, Zhixiang Xu, H.Ohta
    • Journal Title

      Journal of Thermal Science Vol.12, No.2

      Pages: 144-150

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] The Effect of Spherical Surface on Jet Screech suppression2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu, H.Ohta
    • Journal Title

      Aerothermodynamics of Internal Flow Vol.2

      Pages: 338-343

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Jet Noise Reduction by using a Spherical Reflector2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu
    • Journal Title

      Proc.internoise 2003 No.1022

      Pages: 4325-4331

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Aeroacoustic Performance of Perforated Tube with Oblique Perforation2003

    • Author(s)
      Kunisato Seto, Md.Tawhidul Islam Khan, Zhixiang Xu, Hiromitsu Ohta
    • Journal Title

      Proc.internoise 2003 No.1023

      Pages: 4332-4337

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2006-07-11  

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