Misc - MURATA Yorinobu

粒子分散媒体における超音波の周波数応答特性

村田頼信

5回超音波シンポ   89   1998

A new vector velocimetry by real time ultrasonic imaging using M-sequence encoding array transducer

Y Murata, H Toda, Y Tamura, K Koyama

1998 IEEE ULTRASONICS SYMPOSIUM - PROCEEDINGS, VOLS 1 AND 2 ( IEEE )    763 - 766   1998

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In order to measure velocity vector of moving object in water, we have developed a new vector velocimetry using ultrasound. Velocity vector was measured by real-time ultrasonic imaging using M-sequence encoding array transducer. When this array transducer was applied to ultrasonic imaging, a cross section image was obtained by a transmitting and receiving process.
In experiment, we tried to measure the two dimensional velocity vector of a wire target moving at a constant velocity of 10.0 mm/s and at a constant angle of 45 degrees away from the transducer surface. An ultrasonic pulse was transmitted with a constant interval time of 10.0 ms, and We obtained ultrasonic images of 16. The system was operated at the frequency of 2.5 MHz, Images at each acquisition were reconstructed by correlation method. The velocity vector was calculated by the trajectory of target in each image. In conclusion, it was found that the velocity vector of the target be measured with accuracy 4 % by the developed vector velocimetry.

A Basic Study on Vector Velocimetry Using Ultrasonic Encoding Aperture Transducer

村田 頼信, 戸田 裕己, 木下 伸司, 田村 安孝, 小山 清人

大会講演概要集   1997 ( 2 ) 33 - 36   1997.11

超音波符号化開口トランスデューサによる速度ベクトル計測の基礎的検討

村田頼信

9年度秋季大会   33   1997

Development of Ultrasonic Transducer Using Piezoelectric Copolymer Film for Ultrasonic Imaging

6th SPSJ Int. Polymer Conf.   pp.294   1997

Development of Ultrasonic Transducer Using Piezoelectric Copolymer Film for Ultrasonic Imaging

N. Kawakami, Y. Tamura, Y. Murata, Y. Masubuchi, J. Takimoto, K. Koyama, Development of, Ultrasonic Transducer Using Piezoelectric Copolymer Film for, Ultrasonic Imaging

6th SPSJ Int. Polymer Conf.     pp.294   1997

Flow of Polymer Melt in a Disk-shaped Mold under Ultrasound Radiation

MURATA Yorinobu, KIMURA Satoshi, MINAGAWA Keiji, TAKIMOTO Jun-ichi, KOYAMA Kiyohito

Journal of the Japan Society of Polymer Processing ( The Japan Society of Polymer Processing )  7 ( 9 ) 478 - 567   1995

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We proposed a new technique for stirring polymer melt in a mold by acoustic streaming to prevent formation of weldlines in injection molding process. We have demonstrated the generation of the acoustic streaming in high viscosity polymer melt. We radiated ultrasound in a disk-shaped mold to induce the acoustic streaming in the thickness direction of the mold. The acoustic streaming in the polymer melt was examined by observing, after cooling, the displacements of tracers in the cross section of the molded product. We have succeeded in generating the acoustic streaming in the polymer melt of 11000Pa·s in the mold. The acoustic streaming was, however, strongly affected by reflected waves from the surface of the melt. We have found that the acoustic streaming can be efficiently generated in the mold if the interference with the reflected waves are decreased by using a tone-burst ultrasound.

DOI