2012 年 78 巻 787 号 p. 504-512
Progressive ultrasonic waves cause acoustic streaming in a liquid. Although theoretical and experimental studies on acoustic streaming for liquid phase have been carried out, the acoustic streaming for a solid-liquid mixture dose not seems to be investigated. The purpose of this study is to clarify the velocity distribution of acoustic streaming in a solid-liquid mixture. An ultrasonic wave with a frequency of 485 kHz was irradiated on tap water or tap water with aluminum particles in a cylindrical container with a diameter of 120 mm whose orientation was kept horizontal; the acoustic streaming velocities were measured with the irradiation time of ultrasonic wave, particle concentration, and particle shape as the parameters. The followings were obtained: (a) The higher the particle concentration is, the faster the acoustic streaming velocity of solid-liquid mixture becomes; (b) When ultrasonic waves were irradiated on a liquid with heavier solid particles, the acoustic streaming velocity of the solid-liquid mixture decreases with irradiation time to a certain extent.