Laboratory for Flow Control-Fluid mechanics experiment for science & technology-

Deep-sea air-lift pumps

Development of mining technology for valuable mineral resources currently expands worldwide. Japan, the country surrounded by deep ocean, has a long history of the development since 1950. In this 21^st century, the technology attracts further great attention because of increased demands for rare-Earth materials required for high-technology devices. Our laboratory has been developing ultrasound monitoring technique for various multiphase flows[1]. The monitoring technique supports efficient transport of the resources mixed in air and seawater in three-phase flow status in a long vertical pipeline. The technology covers real-time measurement of liquid flow rate[2], void fraction[3], solid concentration[4], and rheological properties of the mixture[5]. This project is operated upon collaboration with JOGMEC, NEDO, The University of Tokyo, and The National Maritime Research Institute of Japan. Recently, we established such an ultrasound technique demonstrated by a laboratory scale air-lift three-phase pump, and found its internal multiphase fluid dynamics that occurs when pipe friction of water phase and buoyancy of large bubbles balance with each other locally showing broad spectrum of the intermittent slugging flow structure.

1. Tan, Murai et al. International Journal of Multiphase Flow, 144, 103811 (2021)
2. Murai, Hayashi et al. Experiments in Fluids, 63, 126 (2022)
3. Park, Yoon et al. Experiments in Fluids, 63, 130 (2022)
4. Park, Yoon et al. Experiments in Fluids, 63, 130 (2022)
5. Tiwari and Murai, Experiments in Fluids , 62, 185 (2021)