| Project/Area Number |
06650834
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Metal making engineering
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| Research Institution | Nagoya University |
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Principal Investigator |
KUWABARA Mamoru Nagoya Univ., Faculty of Eng.Assist.Professor, 工学部, 助手 (70023273)
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| Co-Investigator(Kenkyū-buntansha) |
ASAI Shigeo Nagoya Univ., Faculty of Eng., Professor, 工学部, 教授 (80023274)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Ultrasonic Wave / Sound Field / Standing Wave / Natural Convection / Inclusion / Composite / Directional Control / 音響学 |
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| Research Abstract |
For an effective utilization of ultrasonic external force in liquid in materials processing, numerical analysis and measurement has been made on the sound field. Under designed standing wave of ultrasound, model experiments have bee carried out on suppression of thermal convection, coagulated separation of suspended particles, and directional control of reinforcing fibers in composite. The results are summarized as follows :
(1) A numerical scheme based on the characteristic curve method has been developed to analyze one-dimensional sound field. A close agreement between calculated and analytical fields as well as observed ones indicated validity of the scheme. The scheme allows to analyze transient propagation of a wave to result in a standing wave. (2) A two-dimensional numerical scheme based on the finite difference solution of the wave equation has been developed to cope with more complicated sound field. This method allows to design sound field taking configuration and materials of a vessel, depth and properties of liquid bath, and frequency and arrangement of ultrasonic vibrators into consideration. (3) Water model experiments to investigate the effect of ultrasound on thermal convection showed that heated liquid element can be suppressed around sound nodes. Major ultrasonic force acting on a liquid element could be radiation pressure in low energy density case and a body force due to time-averaged gradient of sound pressure in high energy density case. (4) An experiment showed a possible separation of suspended inclusions from liquid bath after their coagulation in plane-like nodes. (5) An effective ultrasonic method for directional control of reinforcing fine fibers in composite has been newly proposed and results of supporting experiments and its mechanism has been discussed.
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